The Commission's studies have confirmed the association between marihuana usage and the consumption of other drugs for curiosity and pleasure. This association holds for all drugs, including over-thecounter and prescription pain relievers, tension relievers, sleeping pills, and stimulants as well as hashish, methamphetamines, cocaine, LSD and mescaline, and heroin. The National Survey showed that current marihuana users are about twice as likely to have used any illicit drugs than are those who have ceased using marihuana (Table 3).

Table 3.-ILLICIT DRUG USE BY ADULTS

Have used Currently

but no using

Substance Never used marihuana longer use marihuana

marihuana (percent)

(percent)

Hashish Less than 0.5 percent 28 63

LSD or mescaline Less than 0.5 percent 11 28

Methamphetamine Less than 0.5 percent 10 23

Cocaine Less than 0.5 percent 4 10

Heroin Less than 0.5 percent 1 4

The Commission additionally has contracted a study of 105 selected, middle class, young, working adults from California, who are marihuana smokers. Of this sample, 11% were daily marihuana users and 47% used it several times a week; 33% used it several times a month; 6% used it once to several times a year; and 3% had used it but were not currently using marihuana. The study indicates that while most of the subjects were frequent marihuana users, the incidence of other drug use was relatively low (Table 4).

Table 4.-FREQUENCY OF OTHER DRUG USE BY MARIHUANA USERS

Percent who use marihuana

Percent

Substance who Once to Several Several

never several times times Daily

used times a month a week

marihuana a year


Hashish	42	31	21	5	0
LSD	96	4	0	0	0
Mescaline	79	19	0	0	2
Psilocybin	96	4	0	0	0
STP, DMT	100	0	0	0	0
Heroin	98	2	0	0	0
Codeine	87	11	0	0	2
Amphetamines	89	7	0	4	0
Barbiturates	86	10	4	0	0
Cocaine	75	19	2	4	0
Glue	100	0	0	0	0

With the exception of marihuana and hashish, no drug was used by more than 25% of this population and this use was almost exclusively experimental. Interestingly, the more exotic drugs, mescaline and cocaine were more frequently used (21% and 25% of this sample respectively) than the common dangerous drugs: LSD (4%), heroin (2%), codeine (11%), barbiturates (14%), and amphetamines (11%).

Among high school students, marihuana, is normally the, first illicit drug used, although several recent studies have suggested that a significant number of students initiate illicit use, with other drugs. Of the marihuana users, a majority have used no other illicit drug, and they tend to be experimental or intermittent users of marihuana.

The more frequently the adolescent uses marihuana, the more likely he is to experiment with other drugs. For example, in one recent study of San Diego high school students of predominantly white middle socioeconomic background, 80% of the students who used marihuana weekly or more often had used other drugs, and 50% of this group had used LSD. In contrast, 33% of the less than weekly users bad used other drugs.