Data regarding open-label treatment with fluoxetine following failure to respond to tricyclic antidepressants (TCAs) or intolerance of TCA side effects, suggest a response rate between 51.4% and 62.1%, depending on the definition of TCA refractoriness employed. Double-blind study of this issue would extend these findings. Fluoxetine is well tolerated in patients unable to tolerate TCAs. Within this population, more than 80% of patients unable to tolerate TCAs found fluoxetine acceptable. Fluoxetine, as an alternative to polypharmaceutical augmentation, may represent a logical choice as the next step in therapy for a patient who has initially been treated with a TCA and has proven refractory or intolerant.