Pahnke's "Good Friday Experiment":
A Long-Term Follow-Up and
©The Journal of Transpersonal Psychology, 1991, Vol. 23, No.1
On Good Friday, 1962, before services commenced in Boston University's
Marsh Chapel, Walter Pahnke administered small capsules to twenty
Protestant divinity students. Thus began the most scientific experiment
in the literature designed to investigate the potential of psychedelic
drugs to facilitate mystical experience (Pahnke, 1963, 1966, 1967,
1970; Pahnke & Richards, 1969a, 1969b, 1969c). Half the capsules
contained psilocybin (30mg), an extract of psychoactive mushrooms,
and the other half contained a placebo. According to Pahnke, the
experiment determined that "the persons who received psilocybin
experienced to a greater extent than did the controls the phenomena
described by our typology of mysticism" (Pahnke, 1963, p.
This paper is a brief methodological critique and long-term follow-up
study to the "Good Friday Experiment." Pahnke, who was
both a physician and a minister, conducted the experiment in 1962
for his Ph.D. in Religion and Society at Harvard University, with
Timothy Leary as his principal academic advisor (Leary, 1962,
1967, 1968). Describing the experiment, Walter Houston Clark,
1961 recipient of the American Psychological Association's William
James Memorial Award for contributions to the psychology of religion,
writes, "There are no experiments known to me in the history
of the scientific study of religion better designed or clearer
in their conclusions than this one" (Clark, 1969, p. 77).
Since a classic means of evaluating mystical experiences is by
their fruits, follow-up data is of fundamental importance in evaluating
the original experiment. A six-month follow-up was part of the
original experiment and a longer term follow-up would probably
have been conducted by Pahnke himself had it not been for his
death in 1971. For over twenty-five years it has not been legally
possible to replicate or revise this experiment. Hence, this long-term
follow-up study, conducted by the author, is offered as a way
to advance scientific knowledge in the area of psychedelics and
experimental mysticism. Lukoff, Zanger and Lu's review (1990)
of psychoactive substances and transpersonal states offers a recent
overview of this topic.
Though all raw data from the original experiment is lost, including
the uncoded list of participants, extensive research over a period
of four years and the enthusiastic cooperation of most of the
original subjects have resulted in the identification and location
of nineteen out of the original twenty subjects. From November,
1986 to October, 1989, this author tape recorded personal interviews
with sixteen of the original subjects meeting fifteen in their
home cities throughout the United States and interviewing one
subject (from the control group) over the telephone. In addition
to the interviews, all sixteen subjects participating in the long-term
follow-up, nine from the control and seven from the experimental
group, were re-administered the six-month 100-item follow-up questionnaire
used in the original experiment.
Of the remaining three subjects from the experimental group, one
is deceased. The identity of another is unknown. One declined
to participate citing concerns about privacy. One subject, from
the control group, declined to be interviewed or to fill out the
questionnaire because he interpreted Pahnke's pledge of confidentiality
to mean that the subjects should not talk about the experiment
to anyone. This author's discussion of the meaning of confidentiality
and mention of the explicit support for the long-term follow-up
by Pahnke's wife failed to enlist his participation.
Informal discussions were also conducted with seven out of the
ten of Pahnke's original research assistants for purposes of gathering
background information about the experiment. At the time of the
experiment, these people were professors or students of religion,
psychology and philosophy at universities, colleges and seminaries
in the Boston area.
METHODOLOGY OF THE ORIGINAL EXPERIMENT
Pahnke hypothesized that psychedelic drugs, in this case psilocybin,
could facilitate a "mystical" experience in religiously
inclined volunteers who took the drug in a religious setting.
He further hypothesized that such experiences would result in
persisting positive changes in attitudes and behavior.
Pahnke believed the most conducive environment for his experiment
would be a community of believers participating in a familiar
religious ceremony designed to elicit religious feelings, in effect
creating an atmosphere similar to that of the tribes which used
psilocybin-containing mushrooms for religious purposes (Harner,
1973; Hofmann, Ruck & Wasson, 1978; Hofmann & Schultes,
1979; Wasson, 1968). Accordingly, the experiment was designed
to administer psilocybin to a previously acquainted group of Christian
divinity students in church during a Good Friday service.
Methodologically, the study was designed as a randomized controlled,
matched group, double-blind experiment using an active placebo.
Prior to Good Friday, twenty white male Protestant volunteers,
all of whom were students at the same theological school in the
Boston area, were given a series of psychological and physical
tests. Ten sets of closely matched pairs were created using variables
such as past religious experience, religious background and training,
and general psychological makeup. On the morning of the experiment,
a helper who did not participate further in the experiment and
who did not know any of the subjects, flipped a coin to determine
to which group, psilocybin or placebo, each member of the pair
would be assigned.
Three different methods were used to create numerical scales quantifying
the experiences of the subjects in terms of an eight-category
typology of mystical experiences designed by Pahnke especially
for the experiment. Blind independent raters trained in content-analysis
procedures scored descriptions of the experiences written by the
subjects shortly after Good Friday as well as transcripts of three
separate tape-recorded interviews conducted immediately, several
days and six months after the experiment. A 147-item questionnaire
was administered to the subjects one or two days after Good Friday
and a 100-item questionnaire was administered six months after
the experiment. The subject's responses to the interview and the
two questionnaires were transformed into three distinct scores
averaging the percentage of the maximum possible score in each
category. Each of the three complementary scores was then compared
to each other.
Pahnke secured support and permission to use Marsh Chapel from
Rev. Howard Thurman, Boston University's dynamic black chaplain.
Several small meeting rooms and a self-contained basement chapel
were set aside on Good Friday for the participants in the experiment
while the main service led by Rev. Thurman was taking place upstairs
in the larger chapel. The two-and-a-half hour service was broadcast
into the basement chapel, where altar pews, stained glass windows
and various religious symbols were permanently located.
Pahnke gave an active placebo of nicotinic acid to the controls
who were expecting to receive either the psilocybin or an inactive
placebo. This was done in order to "potentiate suggestion
in the control subjects, all of whom knew that psilocybin produced
various somatic effects, but none of whom had ever had psilocybin
or any related substance before the experiment" (Pahnke,
1963, p. 89).
The ten research assistants worked as part of the experimental
team in order to provide emotional support to the subjects prior
to and during the service. Subjects were divided into five groups
of four with two research assistants, known as group leaders,
assigned to each group. These small groups met for two hours prior
to the service to build trust and facilitate group support. Subjects
were encouraged to "go into the unexplored realms of experience
during the actual experiment and not try to fight the effects
of the drug even if the experience became very unusual or frightening"
(Pahnke, 1963, p. 96).
As a precaution against biasing the subjects toward the typology
of mystical experience, leaders were told not to discuss specific
aspects of the psychedelic or mystical experience. The lack of
overt bias was confirmed by all of the subjects in their long-term
follow-up interviews. In a typical long-term follow-up report,
psilocybin subject S.J. (all initials used to identify subjects
are coded to preserve anonymity) made the following remarks both
about the preparation phase of the experiment and the conduct
of the group leaders:
None of the fine points of the mystical experience were given
to us. We were not told to read any books such as Stace's book
on mysticism or Jacob Boheme's books, nothing like that. They
did not bias us in any way towards that, not at all.
At the insistence of one of the group leaders as well as Pahnke's
faculty sponsor, Timothy Leary, but over the objections of Pahnke,
all of the group leaders were also given a pill prior to the service
(Leary, 1984, p. 107). This was done in a double-blind manner
with one of each group's leaders receiving a half dose of psilocybin
(15 mg) and the other the placebo. Pahnke was concerned this would
lead to charges of experimenter bias being leveled against the
study, but Leary and the group leader felt that the full involvement
of the group leaders would create more of a community feeling
and lend necessary confidence to the subjects. Though administered
a capsule at the Good Friday service, the group leaders' reactions
were not tape recorded, nor did they fill out questionnaires.
Pahnke himself refrained from having any personal experiences
with any psychedelic drug until after the experiment and follow-up
had been completed.
The double-blind was successfully sustained through all of the
preparation phases of the experiment up to and including ingestion
of the capsule. The double-blind was even sustained for a portion
of the Good Friday service itself because of the use of nicotinic
acid as an active placebo. Nicotinic acid acts more quickly than
does psilocybin and produces a warm flush through vasodilation
of blood vessels in the skin and general relaxation. Subjects
in the placebo group mistakenly concluded, in the early stages
of the experiment, that they were the ones who had received the
psilocybin (Pahnke, 1963, p. 212). The group leaders, unaware
that an active placebo was going to be used, were also initially
unable to distinguish whether subjects had received the psilocybin
or the placebo.
Psilocybin's powerful subjective effects were eventually obvious
to all subjects who received it, even though they had not previously
ingested the drug or anything similar to it (Pahnke, 1963, p.
212). Inevitably, the double-blind was broken during the service
as the psychoactive effects of the psilocybin deepened and the
physiological effects of the nicotinic acid faded. At the end
of the day of the experiment, all subjects correctly determined
whether they had received the psilocybin or the placebo even though
they were never told which group they were in (Pahnke, 1963, p.
210). Pahnke himself remained technically blind until after the
six-month follow-up. The comments of subject O.W., gathered in
the course of this author's long-term follow-up, are typical of
members of the control group.
After about a half hour I got this burning sensation. It was more
like indigestion than a burning sensation. And I said to T.B.,
"Do you feel anything?" And he said, "No, not yet."
We kept asking, "Do you feel anything?" I said, "You
know, I've got this burning sensation, and it's kind of uncomfortable."
And T.B. said, "My God, I don't have it, you got the psilocybin,
I don't have it." I thought, "Jeez, at least I was lucky
in this trial. I'm sorry T.B. didn't get it, but I'm gonna' find
out." I figured, with my luck, I'd probably get the sugar
pill, or whatever it is. And I said to Y.M., "Do you feel
anything?" No, he didn't feel anything. So I sat there, and
I remember sitting there, and I thought, "Well, Leary told
me to chart my course so I'm gonna' concentrate on that."
And I kept concentrating and sitting there and all I did was get
more indigestion and uncomfortable.
Nothing much more happened and within another 40 minutes, 45 minutes,
everybody was really quiet and sitting there. Y.M. was sitting
there and looking ahead, and all of the sudden T.B. says to me,
"Those lights are unbelievable." And I said, "What
lights?" He says, "Look at the candles." He says,
"Can you believe that?" And I looked at the candles,
and I thought, they look like candles." He says, "Can't
you see something strange about them?" So I remember squinting
and looking. I couldn't see anything strange. And he says, "You
know it's just spectacular." And I looked at Y.M. and he
was sitting there saying, "Yeah." And I thought, "They
got it, I didn't."
The follow-up interviews yielded no evidence that the experimental
team consciously used their knowledge of which pill the subjects
had received to bias the results. However, unconscious bias resulting
in an "expectancy effect" cannot be ruled out (Barber,
1976). Still, valuable information can be generated without the
successful use of the double-blind methodology. Louis Lasagna,
Director of the Center for the Study of Drug Development at Tufts
We have witnessed the ascendancy of the randomized, double-blind,
controlled clinical trial (RCCT), to the point where many in positions
of authority now believe that data obtained via this technique
should constitute the only basis for registering a drug or indeed
for coming to any conclusions about its efficacy at any time in
the drug's career. My thesis is that this viewpoint is untenable,
needlessly rigid, unrealistic, and at times unethical.... Modern
trial techniques [were not] necessary to recognize the therapeutic
potential of chloral hydrate, the barbiturates, ether, nitrous
oxide, chloroform, curare, aspirin, quinine, insulin, thyroid,
epinephrine, local anesthetics, belladonna, antacids, sulfonamides,
and penicillin, to give a partial list... (Lasagna, 1985, p.
Commenting about the attempt to remove the experimenter from the
experiment completely, Tooley and Pratt remark:
In certain participant-observer situations (e.g. psychotherapy,
education, change induction, action research) the purpose might
be to influence the system under investigation as much as possible,
but still accounting for (though now exploiting) the variance
within the system attributable to the several significant and
relevant aspects of the investigator's participant observation....
From this perspective, the quixotic attempt to eliminate the effects
of participant-observation in the name of a misplaced pseudo-objectivity
is fruitless, not so much because it is impossible but because
it is unproductive.... From our point of view... the question
becomes not how to eliminate bias (unaccounted-for influence)
of participant observation, but how optimally to account for and
exploit the effects of the participant observation transaction
in terms of the purposes of the research (Tooley & Pratt,
1964, p. 254-56).
The loss of the double-blind makes it impossible to determine
the relative contributions of psilocybin and suggestion in producing
the subjects' reported experiences. If the experiment were designed
specifically to measure the pure drug effects of psilocybin, the
failure of the double-blind would be quite damaging. In this instance
the loss of the double-blind is of lesser significance because
the entire experiment was explicitly designed to maximize the
combined effect of psilocybin and suggestion. The setting was
religious, the participants were religiously inclined and the
mood was positive and expectant. Pahnke did not set out to investigate
whether psilocybin was able to produce mystical experiences irrespective
of preparation and context. He designed the experiment to determine
whether volunteers who received psilocybin within a highly supportive,
suggestive environment similar to that found in the ritual use
of psychoactive substances by various native cultures would report
more elements of a classical mystical experience (as defined by
the questionnaires) than volunteers who did not receive psilocybin.
The loss of the double-blind may have enhanced the power of suggestion
to some extent and suggests that restraint should be used in attributing
the experiences of the experimental group exclusively to the psilocybin
Critique of the Questionnaire
Pahnke designed the questionnaire he used to measure the occurrence
of a mystical experience specifically for the experiment. No similar
questionnaires existed at the time (Larson, 1986; Rue, 1985; Silverman,
1983). Pahnke decided to measure the mystical experience in reference
to eight distinct experiential categories. The categories include
1) sense of unity, 2) transcendence of time and space, 3) sense
of sacredness, 4) sense of objective reality, 5) deeply felt positive
mood, 6) ineffability, 7) paradoxicality and 8) transiency. These
categories are very similar to those elaborated by such well-respected
scholars of mystical experience as William James (1902), Evelyn
Underhill (1910), and W.T. Stace (1960) and are accepted as valid
even by academic critics of the Good Friday experiment such as
R.C. Zaehner (1972). At present, the scientific questionnaire
most widely used by researchers to assess mystical experiences
is a 32-item questionnaire created by Ralph Hood, also based on
categories developed by W.T. Stace (Spilka, Hood & Gorsuch,
Zaehner's critique of Pahnke's questionnaire is that it does not
contain a category for experiences which are specifically Christian,
such as identification with the death and rebirth of Jesus Christ.
From Zaehner's perspective, this omission made it impossible to
determine if the experiences reported by the subjects during the
Good Friday experiment were religious, since he thought a religious
experience for Christians necessarily involves a theistic encounter
with Christ. Zaehner objected to the claim that an experience
of a generalized, non-specific, apprehension of a transcendent
reality beyond any specific cultural forms and figures could properly
be called religious. Anticipating this critique, Pahnke asserted
in the thesis that he was not attempting to resolve the question
of what can properly be called religious but was simply investigating
mystical experiences, regardless of whether or not they were considered
religious. This author will also leave this delicate discussion
The questionnaire used in the Good Friday experiment has been
modified and expanded over the years by Pahnke, William Richards,
Stanislav Grof, Franco Di Leo, and Richard Yensen for use in subsequent
psychedelic research (Richards, 1975, 1978). From the initial
creation of the questionnaire by Pahnke in 1962 to Di Leo and
Yensen's computerized version, called the Peak Experience Profile,
the basic items relating to the mystical experience have remained
essentially unchanged (Di Leo, 1982). While the original follow-up
questionnaire was composed of eight different categories, the
Peak Experience Profile uses only six. The category of transiency
was eliminated since it measures any altered state of consciousness
whether mystical or not. The paradoxicality and alleged ineffability
categories were combined into the ineffability category. Over
the years, new categories measuring transpersonal but not necessarily
mystical experiences were added. For example, new questions relate
to the reexperiencing of the stages of birth and the perinatal
matrixes as defined by Grof (Grof, 197S, 1980) and also to past-life
experiences (Ring, 1982, 1984, 1988). A series of questions relating
to difficult and painful nadir experiences, in some sense the
opposites of peak experiences, has also been added.
In Pahnke's original questionnaire and in the subsequent revisions,
the completeness with which each subject experienced each category
is measured through numerical responses to category-specific questions.
Pahnke's subjects rated each question on the post-drug questionnaire
from zero to four, with zero indicating that the item was not
experienced at all and four indicating that it was experienced
as strong or stronger than ever before. The six-month follow-up
questionnaire used a zero to five scale, with four indicating
that it was experienced as strong as before and five indicating
that it was experienced stronger than ever before.
The questions themselves are of two types. The predominant type
asks the subject about experiences of a new perspective. For example,
some of the questions used to determine the sense of unity ask
subjects to rate the degree to which they experienced a pure awareness
beyond any empirical content, a fusion of the self into a larger
undifferentiated whole, or a freedom from the limitations of the
self in connection with a unity or bond with what was felt to
be all-encompassing and greater-than-self. These type of questions
are sufficiently detailed and specific to be an effective test
for the specific category.
The second type of question, used much less frequently, asks about
the loss of a normal state. For example, two questions used to
determine the presence of a sense of unity simply required subjects
to rate the degree to which they lost their sense of self or experienced
a loss of their own identity. This type of question is a minor
weak point of the questionnaire because it can be rated highly
without having anything to do with mystical experiences. For example,
one subject reported in the follow-up interview that under the
influence of psilocybin he temporarily had difficulty recalling
his career choice, home, names of his wife and children, and even
his own name. This experience of a powerful loss of the usual
sense of self and identity would be highly correlated with mystical
experience in the questionnaire but may not actually be related
because it can occur for a variety of reasons. Though the questionnaire
has relatively few of this type of question, some overestimation
of the completeness of the mystical experience could have been
introduced into the data as a result.
In addition to asking questions about the experience itself, the
follow-up questionnaire also sought to assess the effects of that
experience on the attitudes and behaviors of the subjects. For
example, the subjects' attitude changes were assessed by asking
them to use a 0 to 5 scale to rate whether they had experienced
an increase or a decrease in their feelings of happiness, joy,
peace, reverence, creativity, vocational commitment, need for
service, anxiety, and hatred. Changes in subjects' behavior were
assessed by means of questions asking whether or not they experienced
changes in their relationships with others, in time spent in quiet
meditation or devotional life, or whether they thought their behavior
had changed in positive or negative ways.
Pahnke's questionnaire gathered information only from the self-reports
of the subjects, resulting in a general sense of the subjects'
own assessment of the direction of the effects of their Good Friday
experience. The data do not yield specific information about the
internal psychodynamic mechanisms at work within each subject,
nor do they include the views of significant others regarding
the effects of the experiment on the subjects.
In contemporary psychotherapy research, more sophisticated methods
than Pahnke's are used to assess personality change (Beutler &
Crago, 1983). Reports from significant others such as family members
and close friends of the subject are almost always used to add
an important "objective" element in assessing personality
change. Data from the follow-up questionnaires, administered by
Pahnke at six-months and by the author after twenty-four to twenty-seven
years, should be considered valuable as far as they go, but this
is not very far. Since no detailed personality tests were given
prior to the experiment, results of such tests at the time of
the long-term follow-up would have been of little value and were
not conducted. The long-term follow-up interviews, because of
their open-ended format and extensive questioning, yielded more
detailed information than the questionnaire about the content
of the experiences and the persisting effects.
FINDINGS OF THE ORIGINAL STUDY AND LONG-TERM FOLLOW-UP
Pahnke arbitrarily determined that for a mystical experience to
be considered complete for the purposes of the experiment, out
of the maximum total possible score, "the total score and
the score in each separate category must be at least 60 to 70
percent" (Pahnke, 1967, p. 66). According to this cut-off
point, "Four of the ten psilocybin subjects reached the 60
to 70 percent level of completeness, whereas none of the controls
did" (Pahnke, 1967, p. 64). Looked at by subjects and categories,
Pahnke reported that "eight out of ten of the experimental
subjects experienced at least seven out of the nine categories.
None of the control group, when each individual was compared to
his matched partner, had a score which was higher" (Pahnke,
1966, p. 647). In every general category and in every specific
question, the average score of the experimental subjects exceeded
that of the control subjects. The differences between the groups
in the scores on the questionnaires were significant at p<.05
level for all categories.
When asked at a conference if any of the controls had a mystical
experience, Pahnke replied,
To take an individual case, there was one control subject who
scored fairly high on sacredness and sense of peace and that he
himself, in his written account, said "It was a very meaningful
experience, but in the past I've certainly had one that was much
more so" (Pahnke, 1966, p. 648).
Pahnke's six-month follow-up data and the author's long-term follow-up
questionnaire data, both of which used the same instrument, are
displayed in Table 1. The six-month scores are listed first and
the long-term follow-up scores follow in parentheses. For each
category, the percentages in the chart represent the total scores
of the subjects divided by the highest possible scores that could
have been reported. The numbers measure the completeness with
which each category was experienced.
At Six-Month Follow-up, Exper. N=10, Control = 10
"GOOD FRIDAY EXPERIMENT" EXPERIMENTAL AND CONTROL GROUPS
AT SIX-MONTH AND LONG-TERM FOLLOW-UP,
SHOWN AS PERCENTAGES OF MAXIMUM POSSIBLE SCORES
|1.Unity A. Internal||60||(77)||5||(5)|
| B. External||39||(51)||1||(6)|
|2. Transcendence of Time and Space||78||(73)||7||(9)|
|3. Deeply Felt Positive Mood||54||(56)||23||(21)|
|5. Objectivity and Reality||71||(82)||18||(24)|
|7. Alleged Ineffability||77||(71)||15||(3)|
| Average for the Categories||60.8||(66.8)||11.8||(12.2)|
|9. Persisting Positive Changes in|
Attitude and Behavior
|10. Persisting Negative Changes in|
Attitude and Behavior
(In Parenthesis) Exper. N=7, Control N=9
p<.05 for all category
comparisons at both six-months and long-term
Comparisons can reliably be made between the control group's six-month
and long-term scores because nine out of the original ten control
group subjects participated in the long-term follow-up and the
variance in scores between control subjects was small. The absence
of completed long-term questionnaires from three of the ten original
subjects from the psilocybin group makes comparing their six-month
and long-term scores more difficult. The long-term follow-up interviews
produced specific information suggesting that one of the three
missing psilocybin subjects had scores significantly lower than
average. No information was generated suggesting that the other
two missing subjects had scores significantly different than average.
The average scores for the long-term follow-up may thus overstate
somewhat the scores from the entire psilocybin group.
The average scores for the eight categories of the mystical experience
and the scores for persisting positive and negative changes in
attitude and behavior have changed remarkably little for either
the controls or the experimentals despite the passage of between
twenty-four and twenty-seven years between the two tests. The
questionnaire seems to be reliable and indicates that time has
not substantially altered the opinions of the subjects about their
experiences. In the long-term follow-up even more than in the
six-month follow-up, the experimental group has higher scores
than the control group in every category. For the long-term follow-up,
these differences are significant at p<.05 in every category.
For the experimental group, the average score for the mystical
categories at the six-month follow-up was 60.8 percent. They scored
66.8 percent at the long-term follow-up. In the six-month follow-up,
the experimental group scored above 34 percent in all categories
while in the long-term follow-up they scored above 48 percent
in all categories. The experimental group scored the highest in
those categories that typify a different state of consciousness
such as transcendence of time and space, alleged ineffability
For the control group, the average score for the eight categories
of mystical experience at the six-month follow-up was 11.8 percent.
They scored 12.2 percent at the long-term follow-up. The highest
score of the control group at either time was 29 percent, in the
sacredness category. The control group scored the highest in the
categories of experience that religious services are most likely
to induce, namely sense of sacredness, deeply felt positive mood
and sense of objectivity and reality.
For the psilocybin group, the long-term follow-up yielded moderately
increased scores in the categories of internal and external unity,
sacredness, objectivity and reality, and paradoxicality, while
all other categories remained virtually the same as the six-month
data. Several decades seem to have strengthened the experimental
groups' characterization of their original Good Friday experience
as having had genuinely mystical elements. For the controls, the
only score that changed substantially was that of alleged ineffability,
A relatively high degree of persisting positive changes were reported
by the experimental group while virtually no persisting positive
changes were reported by the control group. In the open-ended
portion of the long-term follow-up questionnaire, experimental
subjects wrote that the experience helped them to resolve career
decisions, recognize the arbitrariness of ego boundaries, increase
their depth of faith, increase their appreciation of eternal life,
deepen their sense of the meaning of Christ, and heighten their
sense of joy and beauty. No positive persisting changes were reported
by the control group in the open-ended section of the follow-up
There was a very low incidence of persisting negative changes
in attitudes or behavior in either group at either the six-month
follow-up or the long-term follow-up. However, the one psilocybin
subject reported to have had the most difficult time during the
experiment was the one who declined this author's request to be
interviewed in person or fill out a questionnaire, placing in
question the generalizability of this finding for the long-term.
Both the six-month and long-term follow-up questionnaire results
support Pahnke's hypothesis that psilocybin, when taken in a religious
setting by people who are religiously inclined, can facilitate
experiences of varying degrees of depth that either are identical
with, or indistinguishable from, those reported in the cross-cultural
mystical literature. In addition, both the six-month and the long-term
follow-up questionnaire results support Pahnke's hypothesis that
the subjects who received psilocybin, more so than the controls,
experienced substantial positive persisting effects in attitude
THE LONG-TERM FOLLOW-UP INTERVIEWS: GENERAL OVERVIEW
This long-term follow-up was conducted roughly a quarter century
after the subjects participated in the original experiment. All
subjects contacted live in the United States, with five out of
the eight psilocybin subjects and five out of the ten placebo
subjects currently working as ministers. Other professions represented
are stockbroker, lawyer, community developer, social worker, administrative-assistant
and educator. Except for one of the psilocybin subjects, all are
currently married. All are working and self-supporting. All but
two welcomed the opportunity to discuss their participation in
the Good Friday experiment.
Each of the psilocybin subjects had vivid memories of portions
of their Good Friday experience. For most this was their life's
only psychedelic experience, in part because there have been no
legal opportunities for such experiences for the last twenty-five
years in the United States (or in any of the roughly 90 countries
who are party to the international drug control treaties coordinated
by the United Nation's World Health Organization). The experimental
subjects unanimously described their Good Friday psilocybin experience
as having had elements of a genuinely mystical nature and characterized
it as one of the highpoints of their spiritual life. Some subjects
reported that the content of their experience was specifically
involved with the life of Christ and related directly to the Christian
message while others had experiences of a more universal, non-specific
nature. Most of the control subjects could barely remember even
a few details of the service.
Most of the psilocybin subjects had subsequent experiences of
a mystical nature with which they were able to compare and to
contrast to their psilocybin experience. These subsequent experiences
occurred either in dreams, in prayer life, in nature or with other
psychedelics and seemed to the psilocybin subjects to be of the
same essential nature as their Good Friday experience. Significant
differences between their non-drug and drug mystical experiences
were noted, with the drug experiences reportedly both more intense
and composed of a wider emotional range than the non-drug experiences.
The non-drug experiences were composed primarily of peaceful,
beautiful moments experienced with ease while the drug experiences
tended to include moments of great fear, agony and self-doubt.
The discussion of Subject T.B. about the relationship between
his psilocybin and his other mystical experiences illustrates
how the subjects saw the validity of their psilocybin experiences.
I can think of no experiences [like the Good Friday experience]
quite of that magnitude. That was the last of the great four in
my life. The dream state... I had no control over when it was
coming. It was when I [was about nine and] had scarlet fever and
rheumatic fever, apparently at either similar or at the same times.
And they thought that I was going to die. And I saw a light coming
out of the sky, this is in the dream, and it came toward me and
it was like the figure of Christ and I said, "No, let me
live and I'll serve you." And I'm alive and I've served.
The prayer state when I was in seventh grade was very similar
in the way it happened to me. I intentionally went for an experience
with God. In seventh grade. And I also went for an experience
with God at the Good Friday experience. And those were similar.
The West Point experience was different. In that yes, it was prayers,
it was on my knees, it was there, but the face of Christ was.
.. it happened more to me than me participating in it. It was
more like a saving experience kind of thing. So I've had that
and can talk about "a salvation experience," a born
again experience, it was that kind of dedication.
Each of the psilocybin subjects felt that the experience had significantly
affected his life in a positive way and expressed appreciation
for having participated in the experiment. Most of the effects
discussed in the long-term follow-up interviews centered around
enhanced appreciation of life and of nature, deepened sense of
joy, deepened commitment to the Christian ministry or to whatever
other vocations the subjects chose, enhanced appreciation of unusual
experiences and emotions, increased tolerance of other religious
systems, deepened equanimity in the face of difficult life crises,
and greater solidarity and identification with foreign peoples,
minorities, women and nature. Subject K.B.'s description of the
long-term effects is representative. He remarks:
It left me with a completely unquestioned certainty that there
is an environment bigger than the one I'm conscious of. I have
my own interpretation of what that is, but it went from a theoretical
proposition to an experiential one. In one sense it didn't change
anything, I didn't discover something I hadn't dreamed of, but
what I had thought on the basis of reading and teaching was there.
I knew it. Somehow it was much more real to me.... I expect things
from meditation and prayer and so forth that I might have been
a bit more skeptical about before.... I have gotten help with
problems, and at times I think direction and guidance in problem
solving. Somehow my life has been different knowing that there
is something out there.... What I saw wasn't anything entirely
surprising and yet there was a powerful impact from having seen
In addition to self-reports, several subjects who had stayed in
contact with each other over the years spoke about the effects
they noticed in each other. In the instances where such information
was obtained, the observations of fellow subjects were similar
to the self-reports and confirmed claims of beneficial effects.
Several of the psilocybin subjects discussed their deepened involvement
in the politics of the day as one result of their Good Friday
experience. Feelings of unity led many of the subjects to identify
with and feel compassion for minorities, women and the environment.
The feelings of timelessness and eternity reduced their fear of
death and empowered the subjects to take more risks in their lives
and to participate more fully in political struggles.
Subject T.B. discussed how his perception of death during the
Good Friday experience affected his work in the political field.
When you get a clear vision of what [death] is and have sort of
been there, and have left the self, left the body, you know, self
leaving the body, or soul leaving the body, or whatever you want
to call it, you would also know that marching in the Civil Rights
Movement or against the Vietnam War in Washington [is less fearful]....
In a sense [it takes away the fear of dying]... because you've
already been there. You know what it's about. When people approaching
death have an out-of-body experience... [you] say, "I
know what you're talking about. I've been there. Been there and
come back. And it's not terrifying, it doesn't hurt...."
Subject S.J. found that his Good Friday experience of unity supported
his efforts in the political field.
I got very involved with civil rights after that [his psychedelic
experience] and spent some time in the South. I remember this
unity business, I thought there was some link there.... There
could have been. People certainly don't write about it. They write
about it the opposite way, that drugs are an escape from social
obligations. That is the popular view....
Only one of the control subjects felt that his experience of the
Good Friday service resulted in beneficial personal growth. That
particular control subject thought he was probably the one in
the original experiment reported to have had a partial mystical
experience. Ironically, he felt that the most important benefit
he received from the service was the decision to try psychedelics
at the earliest opportunity. The Good Friday service had that
same effect on one other placebo subject, who also had a subsequent
The actual experiences of the original psilocybin subjects are
best communicated by quoting from the transcripts of the long-term
follow-up interviews. Reverend S.J. had an experience almost uniformly
positive. He describes his experience as follows:
Something extraordinary had taken place which had never taken
place before. All of a sudden I felt sort of drawn out into infinity,
and all of a sudden I had lost touch with my mind. I felt that
I was caught up in the vastness of Creation... huge, as the mystics
say.... I did experience that kind of classic kind of blending....
Sometimes you would look up and see the light on the altar and
it would just be a blinding sort of light and radiations The main
thing about it was a sense of timelessness.
The meditation was going on all during this time, and he [Rev.
Howard Thurman] would say things about Jesus and you would have
this overwhelming feeling of Jesus.... It was like you totally
penetrated what was being said and it penetrated you.... Death
looked different. It became in focus.... I got the impression,
the sensation... that what people are essentially in their
essence that somehow they would continue to live. They may die
in one sense, the physical sense, but their being in heaven would
We took such an infinitesimal amount of psilocybin, and yet it
connected me to infinity.
Subject L.J. confronted the issue of personal mortality, which
he described as follows:
I was on the floor underneath the chapel pew and he [a group leader]
was looking after me and sort of aware of, you know, "L.J.
is down there, is everything all right?" I was hearing my
uncle who had died [several months before], the one who was a
minister, saying, "I want you to die, I want you to die,
I want you to die" I could hear his voice saying. The more
that I let go and sort of died, the more I felt this eternal life,
saying to myself under my breath perhaps, "it has always
been this way, it has always been this way.... O, isn't it wonderful,
there's nothing to fear, this is what it means to die, or to taste
of eternal life...." And the more I died the more I appropriated
this sense of eternal life.... While the service went on I was
caught up in this experience of eternal life and appreciating
what the peyote Indians or the sacred mushroom Indians experienced
with their imbibing of the drug. Just in that one session I think
I gained experience I didn't have before and probably could never
have gotten from a hundred hours of reading or a thousand hours
I would have to say as far as I'm concerned it was a positive,
mystical experience... confirmed by experiences both before
Reverend L.R. had one of the most difficult experiences of all
the psilocybin subjects. He described the early portion of his
experience as follows:
Shortly after receiving the capsule, all of a sudden I just wanted
to laugh. I began to go into a very strong paranoid experience.
And I found it to be scary. The chapel was dark and I hated it
in there, just absolutely hated it in there. And I got up and
left. I walked down the corridor and there was a guard, a person
stationed at the door so individuals wouldn't go out, and he says,
"Don't go outside," and I said, "Oh no, I won't.
I'll just look outdoors." And I went to the door and out
I went. They sent [a group leader] out after me. We [L.R. and
the group leader] went back into the building and again, I hated
to be in that building and being confined because there were bars
on the window and I felt literally like I was in prison. One of
the things that was probably happening to me was a reluctance
to just flow. I tried to resist that and as soon as resistance
sets in there's likely to be conflict and there's likely, I think,
for there to be anxiety.
In addition to his emotional struggles, Reverend L.R. discusses
the mystical aspect of his experience as follows:
The inner awareness and feelings I had during the drug experience
were the dropping away of the external world and those relationships
and then the sudden sense of singleness, oneness. And the rest
of normal waking consciousness is really... illusion. It's
not real and somehow that inner core experience of oneness is
more real and more authentic than normal consciousness.... I was
also experiencing some of those same kind of states that produced
anxiety, and I wanted to try to get at the bottom of it.
I personally feel that the experience itself was, and I know his
[Pahnke's] research came to the conclusion, that the effect of
the chemicals like that is very similar, parallel to, perhaps
the same as a classical mystical experience....
Reverend Y.M. describes his experience, which also had some difficult
moments, as follows:
I closed my eyes and the visuals were back, the color patterns
were back, and it was as if I was in an ocean of bands, streams
of color, streaming past me. The colors were brilliant and I could
swim down any one of those colors. Then that swirl dissolved itself
into a radial pattern, a center margin radial pattern with the
colors going out from the center. I was at the center and I could
swim out any one of those colors and it would be a whole different
life's experience. I could swim out any one of them that I wanted.
I mean I could swim metaphorically. There wasn't the sense that
I could actually paddle. I could choose any one I wanted, but
I had to choose one.
I couldn't decide which one to go out, and eventually it connects
to the decision I was in the midst of making about career choices
... when I couldn't decide, I died. Very existential... for
a brief moment there, I was physically dying. My insides were
literally being scooped out, and it was very painful.... I said
to myself... that nobody should have to go through this...
it was excruciating to die like that. Very painful. And I died....
After the psilocybin experience, I never consciously made the
choice as to what I was going to do career-wise, but the choice
was made. It was made while I was on the psilocybin. But it never
had to be consciously, intentionally, "Ah, let's see, what
I am going to do is...." It was made, and I was confident
of it, it was going to be. And I did it afterwards....
Reverend K.B. describes his mystical experience in the following
I feel almost whatever I say about it... is a little bit artificial
in terms of describing. What it is is something deeper and probably
also more obvious and I think I endeavor to put it into some kind
of category which may obscure the point in some way. I remember
feeling at the time that I was very unusually incapable of describing
it. Words are a familiar environment for me and I usually can
think of them, but I didn't find any for this. And I haven't yet.
I closed my eyes, either thinking of meditating or maybe I was
drowsy or something. I closed my eyes and it seemed to be darker
than usual. And then there was a sudden bolt of light which I
think was entirely internal and a feeling almost like a shock
or something and that was only for an instant. It wasn't violent
but it was a definite tingling like taking hold of a wire or something.
I closed my eyes and... thought that this would be a fine time
for [meditating on the Passion].... So I did think about the procession
to the cross. And with my eyes closed I had an unusually vivid
scene of the procession going by. A scene quite apart from any
imagining or anything on my part. A self-actualizing thingkind
of like watching a movie or something, it was apart from me but
I had a definite sense of being an infant or being born, or something
like that. I had a sense of death, too, but I think actually the
sense of death came after the sense of birth.... I had my hands
on my legs and there wasn't any flesh, there were bare bones,
resting on my bones. That part wasn't frightening, I was just
kind of amazed.... I think I must have gone along through the
life of Christ identifying in a very total sort of wayreliving
the life in some way until finally dying and going into the tomb.
I really am glad I took it. And glad that I was a subject. I don't
think it would be a particularly memorable experience if I just
had listened to the service. I've heard some good services and
I imagine this was as moving as most. But I think it would be
in that category instead of a once-in-a-lifetime sort of thing....
I've remained convinced that my ability to perceive things was
artificially changed, but the perceptions I had were real as anything
Subject T.B. was very comfortable with the effects of the psilocybin,
perhaps because he had had mystical experiences prior to the experiment.
He describes his experience in the following way:
I was kneeling there praying and beginning to feel like I was
experiencing the kind of prayer life that I experienced back when
I was in the seventh grade, eleven or twelve years old. It was
the kind of experiences that you knew that something great was
happening. I started to go to the root of all being. And discovered
that... you never quite get there. That was my discovery during
that time... it's a philosophy and a theology that I hold yet
today. You can approach the fullness of all being in either prayer,
or in the psilocybin experience. You can reach out, but you can't
dive down... and hit that root.
The discovery within that experience is that you could approach
God by two different ways. You either get to the root, the ground
of all being, or the fullness of all being. And in getting to
the root, you'll strive, you'll come closer and closer, but it's
always half, and you'll think another half step, another half
step, and you'll never quite get there. The fullness, to approach
the fullness of God is the only way to approach God.
Subject H.R. tells of his largely positive experience in the following
It was a feeling of being... lifted out of your present state.
I just stopped worrying about time and all that kind of stuff
... there was one universal man, personhood, whatever you want
to call it... a lot of connectedness with everybody and every
thing. I don't think Christ or other religious images that I can
remember came into it. That's the only reason I didn't think it
was religious. I don't remember any religious images....
I was convinced after the experiment that I had had quite an experience
but that it was really into my psychological depths, and it was
not a religious experience.... It was really the sense that I
was discovering the depths of my own self. It did not have a sacredness
kind of element to it.... l didn't think I had experienced a God
that was particularly outside of me. What I experienced was a
God that was inside of me. And I think that... made me say,
I don't think this is religious, I think this is psychological.
But that was because of the way I was defining being... the
way I thought God was being defined by other people at that point.
After the Good Friday experiment, two out of the ten placebo subjects
experienced psychedelics. Placebo subject P.J. describes his first
psychedelic experience, which took place in a chapel with psilocybin
subject L.R. as his guide, as follows:
I laid on the front pew and watched myselfit seemed like eternitypour
through my navel and totally become nothing. And I felt that this
would never stop. It seemed like an eternity of being in heaven
and everything. One of the most beautiful experiences in my entire
It sure kicks the hell out of one being rigid with what could
go on and what kind of experiences you could have. To take one
of these drugs says a lot more can happen than what's been happening
in your total experience. And I think that's good, and that's
why I would want my kids to take it.
Placebo subject L.G. received psilocybin in a hospital as a part
of a subsequent experiment conducted by Pahnke (1966) in a fruitless
search for a placebo substance which would permit a successful
double-blind experiment. L.G. describes his experience as follows:
It was rather removed from the religious context. Certainly the
environment we were in had no particular religious symbols. I
recall they really stressed [the need to] be absolutely open and
just relax and flow with the experience whatever comes. So, there
was no context really to suggest a particular experience like
there might have been with the Good Friday experiment. We didn't
talk about mysticism, as I recall, or religious symbols....
At one point I kind of felt like, "Well, maybe this is what
it is like to be crazy." I never really panicked but I was
acutely aware of anxiety.... As time evolved I just had this
incredible sense of joy and humor, too. I was laughing, real ecstasy....
The thing that struck me was how anybody could worry or not trust,
that just struck me as an absurdity. It was very exciting.
There was an energy, it was almost a sexual thing, an intensity
and a joy. The visual things that I experienced and the music,
I think were aligned with the sense of unity, everything was unified.
We were all part of the same thing. You didn't sense a difference
between the music or the physical objects....
I think that you can certainly have a religious experience without
the religious symbols. Certainly the religious symbols can lead
you to a mystical experience. Unfortunately, they can also be
divisive. The sectarianism can flow from the different symbols
and justify the differences rather than the commonality. I think
the mystic experience as I understand it comes down more on the
Contrasting with the desire of two of the control subjects to
have their own psychedelic experience, several of the remaining
control subjects decided during the course of the experiment that
they had no desire to try psychedelics. The behavior of some of
their fellow subjects who received psilocybin had frightened them.
Placebo subject B.A. remarks
I tend to look back on it as an historical curiosity, with intellectual
interest to me, but you know, frankly not much else at this point....
The only change that I can think of that it brought about in my
life was a conviction that I never wanted to go on a drug trip
of any type ever. And I never have, except for booze. The sights
I saw [during the experiment] were very disturbing to me, and
I didn't see myself wanting to be in that kind of position. It
appeared to be hopelessly out of control and life threatening
in several instances.
The remaining control subjects viewed psilocybin with some equanimity
but were not motivated enough to seek out their own experience.
If the circumstances were right and the substances were legal,
several indicated that they might be willing to participate in
A Significant Omission
Out of the seven psilocybin subjects formally interviewed, only
two had had Good Friday experiences that they reported to be completely
positive without significant psychic struggles. The others all
felt moments in which they feared they were either going crazy,
dying, or were too weak for the ordeal they were experiencing.
These struggles were resolved during the course of the Good Friday
service and according to the subjects contributed to their learning
It appears that these difficult moments were significantly underemphasized
in Pahnke's thesis and in the subsequent reporting on the experiment.
Psilocybin subject H.R. states,
The other thing I found unique that wasn't talked at all about
in what I read, at least in the thesis, was that it was all on
the positive up side. I don't know whether other people have said
this but I had a down side.... It was a roller coaster.... I mean
I had a very strong positive sense of the whole... one with
humanity kind of positive glowing, unity kind of feeling and then
I went down to the bottom where I was really just... guilt
... that's all I can say. It was a very, very profound sense
Pahnke does mention that two of the subjects who received the
psilocybin "had a little difficulty in readjusting to the
'ordinary world' and needed special reassurance by their group
leaders until the drug effects subsided" (Pahnke, 1963, p.
219). Almost certainly, one of those subjects was L.R., who found
the chapel to be like a prison and went outside for much of the
service. The other subject is, almost certainly, the one who refused
to participate in the follow-up study.
In one technical section of the thesis, and in none of his subsequent
papers, Pahnke mentions that one of those two subjects later referred
to his experience as "a psychotic episode" (Pahnke,
1963, p. 232). In another part of the thesis, Pahnke mentions
that injectable thorazine was on hand for emergencies. What he
does not report anywhere is that one subject was actually given
a shot of thorazine as a tranquilizer during the course of the
experiment. Several of the subjects and group leaders remembered
this incident and reported in the long-term follow-up interviews
that it involved the one psilocybin subject who refused to be
interviewed by the author. Needless to say, this occurrence should
surely have been mentioned in Pahnke's thesis and, by those few
who knew that such an event had actually transpired, in any subsequent
reporting on the experiment.
Pahnke probably did not report his use of the tranquilizer because
he was fearful of adding to the ammunition of the opponents of
the research. Fears that negative aspects of the experiment would
be taken out of context and exaggerated may have been justified.
In an example of just such a critique, Zaehner asserts in his
book, Zen, Drugs and Mysticism, that Pahnke, in an article Pahnke
published several years after the Good Friday experiment, repudiated
the results of his own study (Zaehner,1972, p.105). In that article,
Pahnke does indeed say that mystical experiences were absent (Pahnke,1967,
p.71). Pahnke was, however, referring to the control subjects.
This misreading of Pahnke by Zaehner is an indication of how,
even in an educated scholar, bias can overwhelm facts. This observation,
of course, is also true of Pahnke. His silence about his administration
of a tranquilizer may perhaps have been good politics; certainly
it was bad science.
Although an interview with the subject who was tranquilized would
be necessary to understand the subtleties of his experience and
its consequences, several long-term follow-up interviews generated
second-hand information which may be summarized as follows: This
subject was reported to be deeply moved by a sermon delivered
by the very dynamic preacher who emphasized that it was the obligation
of all Christians to tell people that there was a man on the cross.
This subject was reported to have gone outside of the chapel possibly
intending to follow the exhortation.
A struggle ensued when the group leaders, worried for his safety,
tried to bring him back inside. After a time during which he seemed
fearful and was not settling down, Pahnke tranquilized him with
a shot of thorazine. He was then brought back into the chapel
and remained calm for the duration of the experiment. He participated
in all further aspects of the experiment and in the six-month
follow-up reported that he considered his fear-experience "slightly
harmful" because "in a mob panic-situation I feel I
would be less likely to maintain a calm objective position than
I might have formerly" (Pahnke, 1963, p. 232).
Subsequent to the Good Friday experiment, the use of tranquilizers
in controlled psychedelic psychotherapy research was largely abandoned
in favor of simply providing a supportive environment and letting
the drug run its course (Richard Yensen, personal communication,
The original Good Friday experiment is one of the preeminent psychedelic
experiments in the scientific literature. Despite the methodological
shortcomings of the unavoidable failure of the double-blind and
the use of several imprecise questions in the questionnaire used
to quantify mystical experiences, the experiment's fascinating
and provocative conclusions strongly support the hypothesis that
psychedelic drugs can help facilitate mystical experiences when
used by religiously inclined people in a religious setting. The
original experiment also supports the hypothesis that those psilocybin
subjects who experienced a full or a partial mystical experience
would, after six months, report a substantial amount of positive,
and virtually no negative, persisting changes in attitude and
This long-term follow-up, conducted twenty-four to twenty-seven
years after the original experiment, provides further support
to the findings of the original experiment. All psilocybin subjects
participating in the long-term follow-up, but none of the controls,
still considered their original experience to have had genuinely
mystical elements and to have made a uniquely valuable contribution
to their spiritual lives. The positive changes described by the
psilocybin subjects at six months, which in some cases involved
basic vocational and value choices and spiritual understandings,
had persisted over time and in some cases had deepened. The overwhelmingly
positive nature of the reports of the psilocybin subjects are
even more remarkable because this long-term follow-up took place
during a period of time in the United States when drug abuse was
becoming the public's number one social concern, with all the
attendant social pressure to deny the value of drug-induced experiences.
The long-term follow-up interviews cast considerable doubt on
the assertion that mystical experiences catalyzed by drugs are
in any way inferior to non-drug mystical experiences in both their
immediate content and long-term positive effects, a critique of
the Good Friday experiment advanced primarily by Zaehner (Bakalar,
Unexpectedly, the long-term follow-up also uncovered data that
should have been reported in the original thesis. Pahnke failed
to report the administration of the tranquilizer thorazine to
one of the subjects who received psilocybin. There is no justification
for this omission no matter how unfairly the critics of this research
may have used the information and no matter how minimal were the
negative persisting effects reported by the subject. In addition,
Pahnke underemphasized the difficult psychological struggles experienced
by most of the psilocybin subjects. These very serious omissions
point to an important incompleteness in Pahnke's interpretation
of the effects of psilocybin.
Some of the backlash that swept the psychedelics out of the research
labs and out of the hands of physicians and therapists can be
traced in part to the thousands of cases of people who took psychedelics
in non-research settings, were unprepared for the frightening
aspects of their psychedelic experiences and ended up in hospital
emergency rooms. These unfortunate instances of panic reaction
have many causes, yet some of them stem from the way in which
the cautionary elements of the Good Friday experiment were inadequately
discussed in Pahnke's thesis, in subsequent scholarly reports
and in the popular media. For example, Time magazine reported
on the experiment in glowing, exaggerated terms stating, "All
students who had taken the drug [psilocybin] experienced a mystical
consciousness that resembled those described by saints and ascetics"
(9/23, 1966, p. 62).
The widespread use of psychedelics, both in medical and nonmedical
settings, which began in the 1960s and is still currently taking
place, apparently largely underground. Such use was partially
founded upon an optimism regarding the inherent safety of the
psychedelic experience which did not fully acknowledge the complexity
and profundity of the psychological issues associated with psychedelic
experiences. With some proponents of psychedelics exaggerating
the benefits and minimizing the risks, a backlash against these
substances was predictable. With the intriguing connection reported
by several psilocybin subjects between mystical experiences and
political action, the backlash in retrospect may have been inevitable
(Baumeister & Placidi, 1985).
Despite the difficult moments several of the psilocybin subjects
passed through, the subjects who participated in the long-term
follow-up reported a substantial amount of persisting positive
effects and no significant long-term negative effects. Even the
subject who was tranquilized in the original experiment reported
only "slightly harmful" negative persisting effects
at the six-month follow-up. Second-hand information gathered during
the course of the long-term follow-up suggests that his experience
caused no persisting dysfunction and may even have had some beneficial
as well as detrimental effects.
The lack of long-term negative effects or dysfunction is not surprising.
Strassman's literature review of all controlled scientific experiments
using psychedelics in human volunteers found that panic reactions
and adverse reactions were extremely rare. He concluded that the
potential risks of future research were outweighed by the potential
benefits (Strassman, 1984).
This long-term follow-up study, even in light of the new data
about the difficulties of the psychedelic experiences of many
of the subjects, adds further support to the conclusion that additional
studies are justified. Future experiments should be approached
cautiously and carefully, with a multidisciplinary team of scientists
involved in planning and implementation. Such a team should include
psychiatrists, psychologists, religious professionals from a variety
of traditions, as well as drug abuse prevention, education and
treatment officials. Questions as fundamental as those raised
by the Good Friday experiment deserve to be addressed by the scientific
community, and pose special challenges to the regulatory agencies.
Renewed research can be expected to require patience, courage
and wisdom from all concerned.
R, J. (1985). Social and intellectual attitudes toward drug-induced
religious experience. J. Humanistic Psychology, 25(4),
BARBER, T.X. (1976). Pitfalls in human research. New York:
BAUMEISTER, R. & PLACIDI, K. (1985). A social history and
analysis of the LSD controversy. J. Humanistic Psychology,
BEUTLER, L.E. & CRAGO, M. (1983). Self-report measures in
psycho therapy outcome. In M. Lamben, E. Christensen, & S.
DeJulio (Eds.), The assessment of psychotherapy outcome.
New York: Wiley.
CLARK, W. H. (1969). Chemical ecstasy: Psychedelic drugs
and religion. New York: Sheed & Ward.
DI LEO, F. (1982). Protocol: LSD-assisted psychotherapy correlation
of peak experience profiles with behavior change. Appendix C:
Peak experience profile. Unpublished.
GROF, S. (1975). Realms of the human unconscious: Observations
from LSD research. New York: Viking Press.
GROF, S. (1980). LSD psychotherapy. Pomona, CA: Hunter
HARNER, M. (Ed.) (1973). Hallucinogens and shamanism.
New York: Oxford University Press.
HOFMANN, A., RUCK, C. & WASSON, R. G. (1978). The road
to Eleusis: Unveiling the secret of the mysteries.
New York: Harvest Books.
HOFMANN, A. & SCHULTES, R. E. (1979). Plants of the gods:
Origins of hallucinogenic use. New York: McGraw-Hill.
JAMES, W. (1961, orig. 1902). Varieties of religious experience.
New York: Collier Books.
LARSON, D. et al. (1986). Systematic analysis of research on religious
variables in four major psychiatric journals, 1978-1982. American
J. Psychiatry, 143 (3), 329-34.
LASAGNA, L. (1985). Clinical trials in the natural environment.
Boston, Tufts University: Center for the Study of Drug Development,
Reprint Series RS 8695. 45-49.
LEARY, T. et al. (1962). Investigations into the religious implications
of consciousness expanding experience. Newsletter #1: Research
program on consciousness-altering substances. Cambridge, MA: Harvard
LEARY, T. (1967). The religious experience: Its production and
interpretation. J. Psychedelic Drugs, 1(2), 3-23.
LEARY, T. (1968). High priest. New York: College Notes
and Texts, Inc.
LEARY, T. (1984). Flashbacks. Los Angeles: J.P. Tarcher.
LUKOFF, D., ZANGER, R. & LU, F. (1990). Transpersonal psychology
research review: Psychoactive substances and transpersonal states.
J. Transpersonal Psychology, 22(2), 107-48.
PAHNKE, W. (1963). Drugs and mysticism: An analysis of the relationship
between psychedelic drugs and the mystical consciousness. Ph.D.
dissertation. Harvard University.
PAHNKE, W. (1966). The contribution of the psychology of religion
to the therapeutic use of psychedelic substances. In Abramson,
H. (Ed.), The use of LSD in psychotherapy and alcoholism.
New York: Bobbs-Merrill, 629-49.
PAHNKE, W. (1967). LSD and religious experience. In DeBold, R.
& Leaf, R. (Eds.), LSD, man and society. Middletown,
CT: Wesleyan University Press, 60-85.
PAHNKE, W. (1970). Drugs and mysticism. In B. Aaronson. &
H. Osmond. (Eds.), Psychedelics: The uses and implications
of hallucinogenic drugs. Garden City, NY: Anchor Books.
PAHNKE, W. & RICHARDS, W. (1969a). Implications of LSD and
experimental mysticism. J. Religion and Health,
PAHNKE, W. & RICHARDS, W. (1969b). The psychedelic mystical
experience and the human encounter with death. Harvard Theological
Review, 62(1), 1 -32.
PAHNKE, W. & RICHARDS, W. (1969c). Implications of LSD and
experimental mysticism. J. Transpersonal Psychology, 1(2),
RICHARDS, W. (1975). Counseling, peak experiences, and the human
encounter with death. Ph.D. dissertation, Washington, D.C.: Catholic
RICHARDS, W. (1978). Mystical and archetypal experiences of terminal
patients in DPT-assisted psychotherapy. J. Religion and
Health, 17(2), 117-26.
RING, K. (1982). Life at death: A scientific investigation
of the near-death experience. New York: Quill.
RING, K. (1984). Heading toward omega: In search of
the meaning of the near-death experience. New
RING, K. (1988). Paradise is paradise: Reflections on psychedelic
drugs, mystical experiences and the near-death experience. J.
of Near-Death Experiences, 6(3), 138-48.
RUE, L.D. (1985). Our most outrageous blind spot: The academic
study of religion. Chronicle of Higher Education, (29),
SILVERMAN, W. (1983). Bibliography of measurement techniques used
in the social scientific study of religion. Psychological Documents
13(7). Washington, D.C.: American Psychological Association.
SPILKA, B., HOOD, JR., R. W. & GORSUCH, R. (1985). The
psychology of religion: An empirical approach. Englewood Cliffs,
NJ: Prentice Hall.
STACE, W.T. (1960). Mysticism and philosophy. London:
STRASSMAN, R. (1984). Adverse reactions to psychedelic drugs:
A review of the literature. J. Nervous and Mental Disease,
TIME. (1966) Mysticism in the Lab. September 23, 62.
TOOLEY & PRATT (1964). Letter to the editor, Behavioral
Science 9(3), 254-56.
UNDERHILL, E. (1974, orig. 1910). Mysticism. New York:
WASSON, R. G. (1968). Soma: Divine mushroom of immortality.
Rome: Harcourt, Brace & Jovanovich, Inc.
ZAEHNER, R.C. (1972). Zen, drugs and mysticism.
New York: Vintage Books.
ZINBERG, N. (1984). Drug, set and setting. New Haven:
Yale University Press.
BIBLIOGRAPHY OF RELATED LITERATURE
AARONSON, B. & OSMOND, H. (Eds.) (1970). Psychedelics:
The uses and implications of hallucinogenic drugs.
Garden City, NY: Anchor Books.
ABRAMSON, H. (Ed.) (1967). The use of LSD in psychotherapy
and alcoholism. New York: Bobbs-Merrill.
BAKALAR, J. (1979-80). Psychedelic drug therapy: Cultural conditions
and obstacles. J. Altered States of Consciousness,
BAKALAR, J. & GRINSPOON, L. (1986). Can drugs be used to enhance
the psychotherapeutic process? American J. of Psychotherapy,
CLARK, W. H. (1973). Religious experience: Its nature
and function in the human psyche. Springfield, IL:
Charles C. Thomas.
D'AQUILI, E. (1982). Senses of reality in science and religion:
A neuroepistemological perspective. Zygon, 17(4), 361-84.
DEAN, S. (Ed.). (1975). Psychiatry and mysticism.
Chicago: Nelson Hall.
DEIKMAN, A. (1982). The observing self: Mysticism and
psychotherapy. Boston: Beacon Press.
DOBKIN DE RIOS, M. (1972). Visionary vine: Hallucinogenic
healing in the Peruvian Amazon. Prospect Heights,
IL: Waveland Press.
EFRON, D. (Ed.) (1967). Ethnopharmacologic search for psychoactive
drugs. Washington, D.C.: Public Health Service Publication
GRINSPOON, L. & BAKALAR, J. (1979). Psychedelic drugs reconsidered.
New York: Basic Books.
GRINSPOON, L. & BAKER, J. (Eds.) (1983). Psychedelic reflections.
New York: Human Sciences Press.
HUXLEY, A. (1954). Doors of perception. New York: Harper.
LEE, M. & SCHLAIN, B. (1986). Acid Dreams: LSD, the CIA
and the sixties rebellion. New York: Grove Press.
MASTERS, R.E.L. & HOUSTON, J. (1966). The varieties of
psychedelic experience. New York: Dell.
MASLOW, A. (1964). Religions. values, and peak experiences.
New York: Viking Press.
MUELLER, R. (1982). New genesis: Shaping a global spirituality.
Garden City, NY: Doubleday.
MYERHOFF, B. (1974). Peyote hunt: The sacred journey
of the Huichol indians. Ithaca, NY: Cornell University
O'CONNELL, S. (1983). The placebo effect and psychotherapy. Psychotherapy:
Theory, research and practice, 20(3), 335-57.
PAHNKE, W. (1966). Report on a pilot project investigating the
pharmacological effects of psilocybin in normal volunteers. Massachusetts
Mental Health Center. Unpublished manuscript.
PERSINGER, M. (1987). The neurophysiological basis for
God experiences. New York: Praeger Press.
PRINCE, R. H. & SALMAN, D. H. (Eds.). (1967). Do psychedelics
have religious implications? Proceedings of the third
annual conference, R. M. Bucke Memorial Society for the Study
of Religious Experience, Quebec.
RAM DASS. (1974). The only dance there is. New York:
SCHMITZ-MOORMAN, K. (1986). Philosophical and theological reflections
on recent neurobiological discoveries. Zygon, 21(2), 249-57.
SHULGIN, A., SHULGIN, L. A. & JACOB III, P. (1986). A protocol
for the evaluation of new psychoactive drugs in man. Methods
and Findings in Experimental Clinical Pharmacology,
SMITH, D. (Ed.) (1967-68). Psychedelic drugs and religion. J.
Psychedelic Drugs, 1(2).
SMITH, H. (1964). Do drugs have religious import? J. Philosophy,
STAFFORD, P. (1983). Psychedelics encyclopedia. Los Angeles:
WEIL, A. (1972). The natural mind. Boston: Houghton
WILBER, K. (Ed.) (1984). Quantum questions: Mystical writings
of the world 's great physicists. Boulder, CO:
WOLMAN, B. & ULLMAN, M. (Eds.) (1986). Handbook of states
of consciousness. New York: Van Nostrand Reinhold.