The close link between suicide attempts and mixed (bipolar) depression:: Implications for suicide prevention

Background: Previous reports have shown a significant relationship between suicide ideation and mixed depression. The aim of this study was to explore the prevalence and clinical characteristics of mixed depression among non-violent suicide attempters. Methods: Using a structured interview (modified Mini International Neuropsychiatric Interview) and assessing all the symptoms of 16 psychiatric diagnoses, the authors examined 100 consecutive nonviolent suicide attempters (aged 18-65) within 24 h after their attempts. Mixed depression was defined as a major depressive episode (MDE)/dysthymic disorder plus 3 or more co-occurring hypomanic symptoms, according to the definition validated by Akiskal and Benazzi [Akiskal, H.S., Benazzi, F., 2003a. Delineating depressive mixed states: Their therapeutic significance. Clin. Approaches Bipolar Disord. 2, 41-47, Akiskal, H.S., Benazzi, F., 2003b. Family history validation of the bipolar nature of depressive mixed states. J. Affect. Disord. 73, 113-122.]. Results: Current mixed depression was present in 63.0% in the total sample, and in 70.8% among the 89 depressive suicide attempters. Irritability, distractibility and psychomotor agitation were present in more than 90% of the subjects with mixed depression. The rate of mixed depression was significantly higher among bipolar than non-bipolar depressive suicide attempters (90% vs. 62%). Patients with mixed depression had the following concurrent disorders: bipolar disorders 41.0%, panic disorder 30.0%, generalized anxiety disorder 89.0%, alcohol abuse/dependence 56.0%, and substance abuse 27.0%. Mixed depression versus non-mixed depression had the following significant associations (odds ratio=OR): females 2.4, bipolar II disorder 9.3, generalized anxiety disorder 41.3, irritability 10 1.6 and psychomotor agitation 61.1. Limitations: The study didn't include suicide attempters with very high risk of fatality. Conclusions: The important new finding of this study is the very high prevalence of mixed depression among depressed suicide attempters. The rates of mixed depression among bipolar and non-bipolar depressive suicide attempters were much higher than previously reported among nonsuicidal bipolar II and unipolar depressive outpatients, suggesting that suicide attempters; come mainly from mixed depressives with predominantly bipolar II base. Irritability and psychomotor agitation were the strongest predictors of suicide attempt. From a public health standpoint, our data highlight the necessity of detecting and treating mixed (bipolar) depression in the prevention of suicidal behaviour. (c) 2006 Elsevier B.V All rights reserved.