Cannabis and psychosis: revisiting a nineteenth century study of ‘Indian Hemp and Insanity’ in Colonial British India
Psychological Medicine May 27, 2019 Oyedeji Ayonrinde 11 citations
A historiographic review of the 1892 Indian Hemp Drugs Commission report shows that heavy cannabis use was linked to severe mental illness, accounting for 7.3% of asylum patients and 12.6% of those with diagnoses. About two-thirds were children and young adults, with higher relapse rates. Risk increased with early cannabis use and family history of mental illness. Cannabis psychosis had a shorter trajectory and better prognosis than other mental illnesses. Different cannabis potency and consumption methods had varying effects, while occasional use was considered medicinally beneficial. The report's observations on dose-related effects and psychosis risk in vulnerable young people align with current knowledge.