The National Commission on Marihuana and Drug Abuse

Marihuana - A Signal of Misunderstanding.

Chapter II

marihuana use and its effects

VERY LONG-TERM EFFECTS OF HEAVY AND VERY HEAVY USE

Knowledge of the effects of very heavy, very long-term use of marihuana by man is still incomplete. The Commission has extensively reviewed the world literature as well as ongoing studies in Jamaica and Greece, and carefully observed very heavy, very long-term using populations in countries in other parts of the world, such as Afghanistan and India. These populations smoke and often drink much stronger drug preparations, hashish and ganja, than are commonly used in America. From these investigations, some observable consequences are becoming much clearer.