In a descriptive report of observations carried out in an Indian drug addiction clinic, 200 patients with a characteristic, transient, and acute drug psychosis were observed following the use of cannabis preparations. Of the patients, 45% had no previous psychopathology. Most patients fully recovered. Among those with the most severe preexisting pathology some patients had a less favorable course; drug psychoses in this group occasionally were dominated by schizophrenic and paranoid symptoms.
Potency and dosage schedule of cannabis, as well as a younger age, were generally related to occurrence of a toxic psychosis. In 16%, and especially among the least stable patients, low potency drug produced symptoms. There were some relationships between purpose of drug consumption, emotional stability, and demographic variables; for the emotionally stable, "sociability" was a dominant motive. There was no direct association with criminal activity.
Chopra GS, Smith JW. Psychotic Reactions Following Cannabis Use in East Indians. Arch Gen Psychiatry. 1974;30(1):24-27. doi:10.1001/archpsyc.1974.01760070014002