Various drugs including antihypertensives, anxiolytics, antibiotics, antidepressants, corticosteroids, choline, indomethacin, levodopa, metronidazole, neuroleptics, oral contraceptives, sulphonamides and physostigmine have been reported to produce depression as a side effect. Clinically, these drug-induced depressions may go unnoticed and thus create therapeutic problems. Although causal relationship is difficult to establish, depression occurring during the course of drug treatment needs an evaluation of all the medications that the patient has been receiving. We believe that postpsychotic depressions include three types of depression: pendular depression--primarily disease related; chronic depression--primarily environment related, and amine-depletion depression--drug related. Thus, drug-induced depressions constitute a subgroup of postpsychotic depression. Clinically, it is essential to carefully monitor patients receiving drugs known to produce depression. Thus, prompt recognition of the drug-induced depressions may assist in initiating proper therapeutic measures.