The importance of dosage in prescribing antidepressants.

The treatment of depressive disorders was significantly altered by the introduction of the tricyclic antidepressants and the monoamine oxidase inhibitors. One salient factor in determining efficacy is the dose prescribed. The few good dose response studies which are available indicate that patients should receive 300 mg of imipramine or equivalent, and a separate trial of 90 mg of phenelzine or equivalent, before concluding they are treatment refractory. Data are reviewed which suggest many patients receive inadequate doses.