The relation between nicotine dependence and suicide attempts in the general population.

Objective: There has been much debate as to whether nicotine is a risk factor for suicidal behaviour. This study sought to examine the relation between nicotine dependence and suicide attempts in a population-based sample of adults.
Method: Our study used the National Epidemiologic Survey on Alcohol and Related Conditions Wave 2 (NESARC; 2004-2005), a large (n = 34,653) nationally representative survey of community-dwelling American adults. Multiple logistic regression analyses examined the relation between suicide attempts and Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, nicotine dependence, compared with nonusers of nicotine. Associations between suicide attempts and other measures of nicotine use (nicotine cessation, age of first use, frequency, and amount of use) were also examined.
Results: Lifetime (AOR 1.78; 95% CI 1.48 to 2.15) and past-year nicotine dependence (AOR 1.77; 95% CI 1.02 to 3.06) were independently associated with lifetime and past-year suicide attempts, respectively, even after adjusting for sociodemographic factors, other mental disorders, and physical disease. Nicotine dependence cessation was associated with a decreased likelihood of suicide attempt compared with people currently dependent on nicotine (AOR 0.15; 95% CI 0.05 to 0.43). Greater amount of daily cigarette use was associated with suicide attempts in the model that adjusted for sociodemographic factors and other mental disorders (AOR 1.53; 95% CI 1.05 to 2.24).
Conclusions: Nicotine dependence is associated with suicide attempts, independently of comorbid mental disorders and physical disease. The association attenuates when a person ceases using nicotine, suggesting a state, rather than trait, effect. These findings provide evidence for additional concern regarding the deleterious health effects of tobacco.