Introduction The public attitude on the personal use of marijuana has changed significantly since the first edition of this book. It appears to be only a matter of time before the legal status of marijuana becomes like that of tobacco (in the past, tobacco use was widely prohibited and its use was grounds for excommunication from the Catholic Church). The use of THC has been allowed in the treatment of glaucoma and to alleviate the unpleasant side effects of chemotherapy in the treatment of cancer. The reports of undesirable effects of marijuana do appear in the scientific literature, but there is no consensus on the damaging effects of the moderate use of marijuana. In contrast, the scientific consensus on damaging effects of