Increased risk for suicidal behavior in comorbid bipolar disorder and alcohol use disorders: results from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC).

OBJECTIVE: Bipolar disorder is associated with a high rate of suicide attempt, and alcohol use disorders have also been associated with elevated risk for suicidal behavior. Whether risk for suicidal behavior is elevated when these conditions are comorbid has not been addressed in epidemiologic studies.
METHOD: 1,643 individuals with a DSM-IV lifetime diagnosis of bipolar disorder were identified from 43,093 general-population respondents who were interviewed in the 2001-2002 National Epidemiologic Survey on Alcohol and Related Conditions. Assessments were made using the National Institute on Alcohol Abuse and Alcoholism Alcohol Use Disorder and Associated Disabilities Interview Schedule-DSM-IV Version (AUDADIS-IV). Lifetime prevalence of reported history of suicide attempt and suicidal thoughts among bipolar disorder respondents with and without DSM-IV lifetime alcohol use disorders (abuse or dependence) was assessed using chi-squared and adjusted odds ratios with confidence intervals. Logistic regression was used to test the relevance of other comorbid clinical conditions to suicide risk in bipolar respondents with and without comorbid alcohol use disorders.
RESULTS: More than half of the respondents (54%) who met criteria for bipolar disorder also reported alcohol use disorder. Bipolar individuals with comorbid alcohol use disorder were at greater risk for suicide attempt than those individuals without alcohol use disorder (adjusted odds ratio=2.25; 95% CI, 1.61-3.14) and were more likely to have comorbid nicotine dependence and drug use disorders. Nicotine dependence and drug use disorders did not increase risk for suicidal behavior among those with bipolar disorder, nor did they confer additional risk among bipolar respondents who also reported alcohol use disorder. Despite greater psychopathological burden, individuals with comorbid bipolar disorder and alcohol use disorder did not receive more treatment or more intensive treatment.
CONCLUSIONS: Suicidal behavior is more likely to occur in bipolar respondents who also suffer from alcohol use disorder. Interventions to reduce suicide risk in bipolar disorder need to address the common and high-risk comorbidity with alcohol use disorders. (c) Copyright 2010 Physicians Postgraduate Press, Inc.