Mixed states and suicidal behavior: a systematic review

Introduction: The objective of this study was to identify whether mixed states in bipolar disorder (BD) are associated with more frequent suicidal behavior when compared to manic/hypomanic and depressive episodes. Method: We performed a systematic search of the scientific literature on the subject using the PubMed, ISI Web Of Science, PsycINFO and SciELO databases. The terms chosen for the search were (bipolar) AND (suicid*) AND (mixed). We selected original studies comparing suicidal behavior of patients in mixed states and suicidal behavior of patients in other BD phases. Results: Sixteen papers fit the selection criteria. Twelve of the original 16 studies compared suicidal behavior in mixed states and pure mania, and the majority of these studies (n = 11) revealed that suicidal behavior was more frequent among individuals in mixed states. Five of the papers compared suicidal behavior between depressive and mixed phases of BD. One of these five papers reported more severe suicidal behavior in patients in mixed states and another described more frequent suicidal behavior in patients with pure depression. There were no significant statistical differences between groups in the remaining three of these five studies. Conclusion: During acute BD episodes, suicidal behavior is more strongly associated with mixed states than with pure mania or hypomania. However, it was not possible to demonstrate that the association between suicidal behavior and mixed states is stronger than the association between suicidal behavior and depressive phases. The results hereby presented are worth considering in clinical practice to better evaluate suicide risk and to prevent suicide.