Smoking and suicidality in subjects with major depressive disorder: results from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC).

BACKGROUND: Detailed characteristics of depressive smokers and its association with suicidality were still less investigated. The aim of this study was to delineate characteristics of smokers with major depressive disorder (MDD) and examine the relationship between these characteristics and suicidality using an epidemiologic database, the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC).

METHODS: A total of 5695 subjects with MDD, defined by the DSM-IV criteria, were included in our analysis. Current smokers, former smokers, and lifetime nonsmokers were compared in terms of demographic, clinical characteristics, and functional level. Suicidality, evaluated by history of suicide ideation and attempts while in a low mood was evaluated and compared among the groups.

RESULTS: Current smokers with MDD showed a greater number of DSM-IV symptoms while in acute episodes, a higher rate of alcohol and drug-use disorders, and poorer functional levels than nonsmokers. Previous smokers displayed intermediate characteristics between current smokers and nonsmokers. The logistic regression analysis revealed that both current and former smoking status predicted the risk of having a history of attempted suicide (current smokers: odds ratio 1.62, 95% C.I. 1.42-1.86; former smokers: odds ratio 1.37, 95% C.I. 1.13-1.66) after adjusting for demographic data, a history of subthreshold hypomania, and a lifetime axis II/anxiety/alcohol use/substance-use disorder.

LIMITATIONS: Retrospective, cross-sectional evaluation; suicidality assessed only in the most severe depressive episode.

CONCLUSIONS: The present study corroborates that smokers with MDD showed distinct clinical characteristics, and cigarette smoking can predict attempted suicide in a community representative sample of people with MDD.