National Commission on Marihuana and Drug Abuse

Marihuana: A Signal of Misunderstanding

Chapter III

Social Impact of marihuana use

Potential For Genetic Damage

The thalidomide tragedies of the 1950's have taught us to ponder carefully the possibility of genetic damage subsequent to any drug use. The much publicized controversy regarding LSD and subsequent genetic damage has led investigators to study marihuana and its possible genetic effects. Although a number of studies have been performed, at present no reliable evidence exists indicating that marihuana causes genetic defects in man.

Early findings from studies of chronic (up to 41 years), heavy (several ounces per day) cannabis users in Greece and Jamaica also failed to find such evidence. In all its studies, the Commission found no evidence of chromosome damage or teratogenic or mutagenic effects due to cannabis at doses commonly used by man. However, since fetal damage cannot be ruled out, the use of marihuana like that of many other drugs, is not advisable during pregnancy.