Suicidal Behavior in Bipolar Disorder: What Is the Influence of Psychiatric Comorbidities?

Objective: To assess the frequency of some psychiatric comorbidities found to be associated with suicidal behavior in previous studies and to evaluate their influence on suicidal behavior in a sample of patients with bipolar disorder.

Method: We assessed 239 bipolar patients from January 2005 to January 2007. Axis I diagnosis was performed according to the DSM-IV using a structured interview (the Mini-International Neuropsychiatric Interview-Plus), and borderline personality disorder was assessed using the Structured Clinical Interview for DSM-IV Axis II Personality Disorders. Lifetime suicide history was assessed using a semistructured interview in addition to a review of medical records.

Results: There were 99 patients (41.4%) with a history of previous suicide attempts. The psychiatric comorbidities associated with suicidal behavior were borderline personality disorder (chi² = 36.008, p = .0001), panic disorder (chi² = 5.537, p = .019), alcoholism (chi² =12.820, p=.001), other drug addictions (chi² = 10.055, p = .02), generalized anxiety disorder (chi² = 10.216, p = .001), and smoking (chi² = 9.070, p = .003). However, when logistic regression analyses were used, only the diagnosis of borderline personality disorder remained significant (Wald chi² = 19.13, p = .0001). When analyzing the subtypes of suicide attempts, we found that borderline personality disorder and alcoholism were associated with violent suicide attempts.

Conclusion: A diagnosis of borderline personality disorder or alcoholism (only for violent subtype of suicidal behavior) was the only comorbidity independently associated with suicide in patients with bipolar disorder. For suicide prevention, screening to identify patients at high risk for suicidal behavior should be performed routinely in patients with bipolar disorder.