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

BACKGROUND: Smoking in patients with bipolar disorder is known to be related to suicidality. This link has not been investigated, however, in community-based samples. The aim of this study is to delineate the sociodemographic and clinical characteristics of bipolar smokers and examine the relationship between these characteristics and suicidal ideation or attempts in an epidemiologic database, the National Epidemiological Survey on Alcohol and Related Conditions (NESARC).
METHODS: Subjects (n = 1,643) with bipolar disorder I and II, defined by the DSM-IV criteria, who had a history of low moods lasting more than 2 weeks 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 a history of suicide ideation and attempts while in low mood were compared.
RESULTS: Current smokers with bipolar disorder showed a greater number of DSM-IV symptoms while in acute episodes, higher rate of alcohol, and drug use disorders, as well as poorer functional levels than nonsmokers. Previous smokers displayed intermediate characteristics between current smokers and nonsmokers. The logistic regression analysis revealed that current smoking status predicted the risk of having a history of attempted suicide (Odds ratio 1.35, 95% CI: 1.05-1.76) after adjusting for age, sex, race, bipolar subtype, lifetime axis II/anxiety/alcohol use/substance use disorder; however, lifetime smoking status did not.
CONCLUSIONS: The present study confirms that current cigarette smoking can predict attempted suicide in a community representative sample of people with bipolar disorder.