If a drug has well-marked pharmacological actions and low toxicity, as appears to be the case with marihuana, a consideration of special interest is its possible therapeutic application. In the older clinical literature marihuana was recommended for use in a wide variety of disorders, but in recent years it has almost disappeared from the materia medica and it was dropped from the United States Pharmacopeia twenty years ago.

In view of the laboratory and clinical findings obtained in this study the question of the therapeutic possibilities of the drug was considered. Marihuana possesses two qualities which suggest that it might have useful actions in man. The first is the typical euphoria-producing action which might be applicable in the treatment of various types of mental depression; the second is the rather unique property which results in the stimulation of appetite. In the light of this evidence and in view of the fact that there is a lack of any substantial indication of dependence on the drug, it was reasoned that marihuana might be useful in alleviating the withdrawal symptoms in drug addicts.

At the Riker's Island Penitentiary observations were made on 56 inmates who were addicted to morphine or heroin. Two groups were selected, the addicts in each being matched with those in the other group as to age, physical condition, duration and intensity of habit, and number of previous attempts at cure. The subjects in one group received no treatment or were given Magendie's solution according to the usual hospital regimen, while those in the other group were treated with 15 mg. of tetrahydrocannabinol three times daily with or without placebo (subcutaneous water injection). An attempt was made to evaluate the severity of the withdrawal signs and symptoms. The impression was gained that those who received tetrahydrocannabinol had less severe withdrawal symptoms and left the hospital at the end of the treatment period in better condition than those who received no treatment or who were treated with Magendie's solution. The ones in the former group maintained their appetite and in some cases actually gained weight during the withdrawal period.

Since psychological factors play a large part in the withdrawal symptoms of at least a certain proportion of morphine addicts, there are grounds for the assumption that a drug having the properties of marihuana might be of aid in alleviating mental distress during the withdrawal period. However, the studies here described were not sufficiently complete to establish the value of such treatment, and before conclusions can be drawn the problem must be investigated under completely controlled conditions.