Cannabis abuse and serious suicide attempts

Addiction. 1999 Aug;94(8):1155-64. doi: 10.1046/j.1360-0443.1999.94811555.x.


Aims: To compare the relationship between cannabis abuse/dependence and risk of medically serious suicide attempts in individuals making serious suicide attempts and randomly selected comparison subjects.

Design: Case-control comparison.

Setting: Cases, a general hospital; controls, the local community.

Participants: Cases were 302 consecutive individuals making medically serious suicide attempts; 1028 randomly selected control subjects.

Measurements: DSM-III-R mental disorder diagnoses; measures of socio-demographic characteristics and childhood and family experiences.

Findings: Of those making serious suicide attempts, 16.2% met DSM-III-R criteria for cannabis abuse/dependence at the time of the attempt, compared with 1.9% of comparison subjects (OR = 10.3; 95%CI, 5.95-17.8, p < 0.0001). Risks of serious suicide attempt were significantly related to a series of socio-demographic and childhood characteristics, and to mental disorders that were co-morbid with cannabis abuse/dependence. When the association between cannabis abuse/dependence and suicide attempt risk was controlled for socio-demographic factors, childhood factors and concurrent psychiatric morbidity, there was a marginally significant association (OR = 2.0; 95%CI, 0.97-5.3, p < 0.06) between cannabis abuse/dependence and serious suicide attempt risk.

Conclusions: These results suggested that much of the association between cannabis abuse/dependence and suicide attempt risk arose because: (a) individuals who develop cannabis abuse/dependency tend to come from disadvantaged socio-demographic and childhood backgrounds which, independently of cannabis abuse, are associated with higher risk of suicide attempt, or (b) because cannabis abuse/dependence is co-morbid with other mental disorders which are independently associated with suicidal behaviour. Nevertheless, the possibility remains that cannabis abuse/dependence may make an independent contribution to risk of serious suicide attempt, both directly and through the possible effects of cannabis abuse on risk of other mental disorders.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Age Distribution
  • Aged
  • Case-Control Studies
  • Female
  • Humans
  • Male
  • Marijuana Abuse / epidemiology*
  • Middle Aged
  • New Zealand / epidemiology
  • Residence Characteristics
  • Risk Factors
  • Sex Distribution
  • Social Class
  • Suicide, Attempted / statistics & numerical data*