Violence and self-harm in severe mental illness: inpatient study of associations with ethnicity, cannabis and alcohol.
OBJECTIVE
We examined the extent to which ethnicity, cannabis and alcohol use could predict prevalence of violence and self-harm in an inpatient psychiatric sample.


METHODS
We collected demographic and clinical data in a series of 141 adult psychiatric inpatients in Hamilton, New Zealand. The Alcohol Use Disorders Identification Test (AUDIT) and Cannabis Use Disorders Identification Test, Revised (CUDIT-R) were used to measure substance use. Clinical assessment and file review were used to verify histories of self-harm and violence.


RESULTS
It was found that 66% had a history of violence, 54% of self-harm, and 40% of both; only 20% had neither. Cannabis use was found to significantly predict lifetime history of violence ( p = 0.02); other independent variables (gender, age, ethnicity, alcohol use, psychiatric diagnosis) did not. Self-harm was strikingly predicted by female gender ( p < 0.001), as well as by measures both of cannabis ( p = 0.025) and alcohol use ( p = 0.036); age, ethnicity and diagnosis did not reach significance. Less than 10% of patients were engaged with drug or alcohol services.


CONCLUSIONS
Cannabis use is a significant predictor of lifetime violence among the severely mentally ill, while both alcohol and cannabis use predict self-harm. Few affected patients receive specific treatment for substance use comorbidity.
Consultant Psychiatrist, Department of Psychiatry, Teaching Hospital, Anuradhapura, Sri Lanka.
Vajira
V
Dharmawardene
Academic Psychiatrist, Waikato Clinical Campus, University of Auckland, Auckland, New Zealand.
David B
DB
Menkes
D000437:Alcoholism; D005006:Ethnicity / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007297:Inpatients / Q000523:psychology / Q000706:statistics & numerical data; D016015:Logistic Models; D008297:Male; D002189:Marijuana Abuse; D009520:New Zealand / Q000453:epidemiology; D011618:Psychotic Disorders / Q000150:complications*; D016728:Self-Injurious Behavior / Q000453:epidemiology*; D019966:Substance-Related Disorders / Q000453:epidemiology*; D014754:Violence / Q000706:statistics & numerical data*
alcohol; cannabis; mental illness; self-harm; violence