Nicotine use in suicides: a case-control study.

Abstract

PURPOSE: Despite of higher rates of substance-related disorders in psychiatric patients and suicides than in the general population, there is no clear specificity to the relationship between nicotine use and other psychiatric disorders for suicide risk. METHODS: One hundred and sixty-three suicides (mean age 49.8 +/- 19.3 years; 64.4% males; using psychological autopsy method) and 396 control persons (mean age 51.6 +/- 17.0 years; 55.8% males) were assessed with a standardised semi-structured interview including SCID-I and SCID-II (for DSM-IV). Suicides and controls were compared in terms of nicotine consumption and psychiatric disorders. Logistic regression was used to evaluate the interactions of tobacco consumption with psychiatric disorders. RESULTS: Suicides were significantly more often current smokers and heavy users of cigarettes (> 20 cigarettes per day; P < 0.001, each). Alcohol dependence, other axis I disorders than substance-related disorders, and cluster B personality disorder(s) remained independent predictors for suicide in both genders, current nicotine consumption only in men (OR = 2.6, 95% CI 1.3-5.2). DISCUSSION AND CONCLUSIONS: In males, but not in females, nicotine consumption contributed to risk of completed suicide after control for psychiatric disorders and has to be considered as independent risk factor for suicide.