Cannabis consumption has been shaped by cultural and religious contexts across history. In medieval Islam, it was linked to Sufi mystical practices, and heavy use was thought to risk inducing madness or psychosis, yet social sanctions were absent. Today in Western societies, cannabis is mainly used by adolescents for relaxation, and public concern focuses on it as a gateway to other illicit drugs, while the risk of psychosis is rarely discussed. Across eras, users have reported creative insights from intoxication, translating unusual experiences into normal reality, but this creative aspect is largely overlooked in scientific research, for reasons the authors discuss.
Among 237 patients examined for drug-induced psychoses, 50 cannabis psychoses and 107 other drug-induced psychoses were compared with 219 schizophrenic patients. The cannabis psychoses showed general agreement in symptomatology with both other drug-induced psychoses and schizophrenia. The variation from schizophrenic symptoms was common to both cannabis and other drug-induced psychoses. The authors conclude there is no distinct disease "cannabis psychosis" or "drug-induced psychosis" as separate entities. While a slight drug-specific psychopathological undertone exists, it does not justify a syndromatic or nosological entity. The psychopathological cross section does not allow differentiation among the psychosis groups. The similarity may reflect either the same underlying pathological process or cannabis-triggered schizophrenia. The authors propose diagnosing symptomatic psychoses by considering etiology alongside syndrome diagnosis.