Is the Higher Number of Suicide Attempts in Bipolar Disorder vs. Major Depressive Disorder Attributable to Illness Severity?

The present study represents an early stage investigation into the phenomenon whereby those with bipolar disorder attempt suicide more frequently than those with unipolar depression, but do not tend to attempt suicide during mania. Data for this study were obtained from baseline measurements collected in a randomized treatment study at a major southwestern United States military medical center. We demonstrated the rarity of suicide attempts during mania, the higher frequency of suicide attempts in those with bipolar disorder compared to those with depression, and the persistence of effects after accounting for severity of illness. These results provide the impetus for the development and testing of theoretical explanations.