The National Commission on Marihuana and Drug Abuse

Marihuana - A Signal of Misunderstanding.

Chapter II

marihuana use and its effects

Definition of Dependence

Before describing the effect of marihuana, on the user, two additional definitions are required. They concern the concept of dependence which has so clouded public and professional consideration of psychoactive drugs. Throughout the remainder of this report, we refer Separately to psychological and physical dependence, defined as follows:

Psychological dependence is the repeated use of psychoactive drugs leading to a conditioned pattern of drug-seeking behavior. The intensity of dependence varies with the nature of the drug, the method, frequency, and duration of administration, the mental and physical attributes of the individual, and the characteristics of the physical and social environment. Its intensity is at its peak when drug-seeking becomes a compulsive and undeviating pattern of behavior.

Physical dependence is the state of latent hyper-excitability which develops in the central nervous system of higher mammals following frequent and prolonged administration of the morphine-like analgesics, alcohol, barbiturates, and other depressants. Such dependence is not manifest subjectively or objectively during drug administration. Specific symptoms and signs, the abstinence syndrome, occur upon abrupt termination of drug administration; or with morphinelike agonists by administering the specific antagonists.