The National Commission on Marihuana and Drug Abuse

Marihuana - A Signal of Misunderstanding.

Chapter II

marihuana use and its effects

EFFECTS RELATED TO PATTERN USE

Set out below is a brief summary of effects of marihuana, related to frequency and duration of use. The remainder of the Chapter discusses the effects of immediate, short-term, long-term and very long-term use of the drug.

Experimenters and

intermittent users ------ Little or no psychological dependence.

Influence on behavior related largely to

conditioning to drug use and its social

value to the user.

No organ injury demonstrable.

Moderate users ------------ Moderate psychological dependence in-

creasing with duration of use.

Behavioral effects minimal in stable per-

sonalities, greater in those with emo-

tional instability.

Probably little if any organ injury.

Duration of use increases probability of

escalation of all effects including shift

from moderate to heavy use.

Heavy users -------------- American "pot head."

Strong psychological dependence.

Detectable behavior changes.

Possible organ injury (chronic diminution of pulmonary function).

Effects more easily demonstrable with long-term use.

Very heavy users ---------- Users in countries where the use of cannabis has been indigenous for centuries.

Very strong psychological dependence to point of compulsive drug seeking and use.

Clear-cut behavioral changes.

Greater incidence of associated organ injury.