These substantial cognitive and psychomotor effects are probably responsible for many of the acute adverse reactions to marihuana. One, of the most common is the heavy, drugged feeling where the individual feels mentally and physically sluggish so that every motion and thought seems to require extreme effort (Smith and Mehl, 1970). This probably reflects impaired cognitive function and psychomotor retardation from getting "too stoned." This most frequently occurs after oral ingestion of a large dose of drugs or in inexperienced smokers who have, not learned to selftitrate their dose to achieve the desired high.

In these instances, depression, anxiety, fatigue, short-term memory loss, dizziness, nausea, incoordination, palpitations are experienced as generalized discomfort, and ill-being.

"Novice anxiety reactions" or panic reactions account for a majority of acute toxic reactions to marihuana (Baker and Lucas, 1969; Baker-Bates, 1935; Gaskill, 1945; Grossman, 1969; Persyko, 1970; Bialos, 1970; Sonnenreich and Goes, 1962; Sigg, 1963; Dally, 1967; Hamaker, 1891; Marten, 1969; Smith and Mehl, 1970; Walton, 1938).

When dosage, set and setting are optimal the distortion of self (depersonalization) and temporal disintegration (timelessness of the present moment) common to marihuana intoxication is recognized by the individual as time-limited and drug-induced. It is usually experienced as pleasurable. But, if dose, set and setting are not optimal the experience may cause the intoxicated individual to fear that loss of his identify and self control may not end or that he is dying or losing, his mind. Acute, anxiety or panic results (Mel et al., 1970).

Non-drug factors of set and setting play a most important role in these, reactions. Of course, the great variability of individuals makes the effect of marihuana on any specific individual rather unpredictable.

The large majority of these anxiety reactions occur in novices who have intense underlying anxiety surrounding marihuana use such as fears of arrest, of disruption of family and occupational relations and of possible physical and mental dangers. Also, individuals with relatively rigid personality structures, whose values are more in line with those of the "straight"society and have little desire for new and different experiences, appear to experience these, anxiety reactions much more frequently than those, individuals who are members of the "counterculture" (Smith and Mehl, 1970).

In addition, simple episodes of neurotic depression may be observed in these, same types of individuals during periods of unusual psychological stress (Well, 1970). Both of these types of reactions are transient and abate as the drug effects wear off over a few hours. Treatment should consist of gentle but authoritative. reassurance that nothing is seriously wrong and that the drug effects will wear off and the individual will feel normal" again (Smith and Mehl, 1970; Well, 1970).