Patients with bipolar disorder are at very high risk for suicidal ideation, non-fatal suicidal behaviors and suicide and are frequently treated with antidepressants. However, no prospective, randomized, controlled study specifically evaluating an antidepressant on suicidality in bipolar disorder has yet been completed. Indeed, antidepressants have not yet been shown to reduce suicide attempts or suicide in depressive disorders and may increase suicidal behavior in pediatric, and possibly adult, major depressive disorder. Available data on the effects of antidepressants on suicidality in bipolar disorder are mixed. Considerable research indicates that mixed states are associated with suicidality and that antidepressants, especially when administered as monotherapy, are associated with both suicidality and manic conversion. In contrast, growing research suggests that antidepressants administered in combination with mood stabilizers may reduce depressive symptoms in patients with bipolar depression. Further, the only prospective, long-term study evaluating antidepressant treatment and mortality in bipolar disorder, although open-label, found antidepressants and/or antipsychotics in combination with lithium, but not lithium alone, reduced suicide in bipolar and unipolar patients (Angst F, et al. J Affect Disord 2002: 68: 167–181). We conclude that antidepressants may induce suicidality in a subset of persons with depressive (and probably anxious) presentations; that this induction may represent a form of manic conversion, and hence a bipolar phenotype, and that lithium's therapeutic properties may include the ability to prevent antidepressant-induced suicidality.