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.
Occultism, parapsychology, and esoterics are compared with religion, spirituality, and mysticism, emphasizing cultural relativity. Occultism involves manipulating phenomena inaccessible to normal perception through magic. Parapsychology in its popular sense addresses occult phenomena, while scientific parapsychology investigates them empirically. Esoterics comprises beliefs about occult processes and destiny after death within a hermetic tradition. Transpersonal psychology frames these as spiritual. Paranormal experiences can affect personality, interpersonal relations, and mental health, potentially causing crises or psychoses, including mediumistic psychoses where splitting of non-ego parts manifests schizophrenic symptoms. Dangers include ego inflation from attributing superhuman power. Schizotypia may predispose to parapsychological perception. Adepts may exhibit a false self as described by Winnicott.
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.