This analysis involved 141 adult psychiatric inpatients in Hamilton, New Zealand, 66% of whom had a history of violence, 54% a history of self-harm, and 40% had a history of both; only 20% had neither. Cannabis use was a significant predictor of lifetime violence (p=0.02); no such association was seen between violence and gender, age, ethnicity, alcohol use, or psychiatric diagnosis. Self-harm was predicted by female gender (p<0.001), by cannabis use (p=0.025) and alcohol use (p=0.036); age, ethnicity and diagnosis did not reach significance. Fewer than 10% of patients were receiving treatment for substance use comorbidity.
