The efficacy of fluoxetine in the treatment of nondelusional, moderately depressed patients is comparable to that of the tricyclic agents; its efficacy in severely depressed hospitalized patients has not been established. In limited studies, fluoxetine was useful in treating patients with atypical depression, panic disorder, and the depressed component of bipolar disorder. Fluoxetine may be indicated as initial therapy in patients with concurrent obsessive-compulsive disorder. Its efficacy in obesity and bulimia is being explored.