The presence of depressive mixed states among patients originally diagnosed with unipolar depression suggests that these patients may actually fall along the bipolar spectrum, which has significant treatment implications. To accurately detect mixed depression, physicians should systematically inquire about the presence of manic and hypomanic symptoms in a formal, structured manner when evaluating a depressed patient. This includes specifically asking patients about symptoms of irritability, racing or crowded thoughts, talkativeness, and psychomotor agitation. Swift and accurate diagnosis of depressive mixed states is essential to alleviating symptoms and improving outcomes for patients with bipolar disorders.