Long-term adverse effects of brief marijuana usage.

Marijuana is known to produce a number of short-lived side effects as well as longer lasting adverse effects resulting from chronic usage. The author wishes to draw attention to the occurrence of long lasting adverse effects which appear to be brought on by one-time usage of marijuana. The author has seen several such cases, 2 of which are presented here. These individuals were functioning well in the presence of mild to moderate psychopathology prior to using marijuana. Subsequently they functioned on a lower level for at least several months and the degree of psychopathology noted was greater.