Predictors of Response to Augmentation With Ziprasidone (Geodon®) in Major Depressive Disorder

The primary outcome of this study is to determine if predictors of response can select a population of patients with MDD that is effectively treatable by augmentation with ziprasidone. Major depressive disorder (MDD) is a broad category, including many forms of depressive illness, including those with only a single major depressive episode, those with episodic recurrence with intervening well states, those with chronic depressive/anxious states without intervening euthymia, and those with manic symptoms that do not meet threshold definitions of full mania/hypomania. In this heterogenous, large diagnostic definition, important groups of patients do not appear to respond well to antidepressants, and, conversely, based on observational studies, may respond well to neuroleptics. These predictors of response have begun to be identified and may serve to better design studies of neuroleptics in depressive illnesses. Among these predictors of response in MDD are clinical features that are more similar to bipolar illness than unipolar depression. These include a family history of bipolar disorder, antidepressant-induced mania, highly recurrent depressive episodes (\>5), atypical depression, early age of onset of depression (\< age 20), failure to respond to antidepressants, and antidepressant tolerance (initial response followed by later loss of response). The investigators propose to use these predictors to pick out patients that are more likely to respond to Geodon for MDD. This will be the first RCT of these predictors of depressive response applied to neuroleptics.