Much speculative nonsense has been written in recent years about the possible harmful effects of hallucinogens. The fact is that we just do not have sufficient reliable scientific evidence about many of the frequently discussed side effects. Reports of such effects often have been circumstantial and indifferent to the possibility of a post hoc ergo propter hoc relationship.
Discussions of the morality of using hallucinogens are relevant but probably deserve no high priority than consideration of the ethics of a society which sanctions—and pockets enormous profits from—the sale of alcohol and cigarettes. Untoward psychic reactions are known to occur with the hallucinogens, although we do not know the incidence or prevalence.
But what of physical harm due to the hallucinogens? Until recently there was little reliable, reproducible data. Beginning in March 1967, however, several groups of investigators have reported the occurrence of chromosomal damage, not only in vitro but also