The effects of a calcium channel blocker (verapamil, 160-320 mg/day for 4 weeks) were studied in seven unipolar major-depressed patients resistant to treatment with tricyclic antidepressants. This regimen of verapamil did not alter either the Hamilton rating scales for depression and anxiety or the Beck depression inventory score in these patients. Thus, verapamil appears devoid of antidepressant properties in patients resistant to tricyclic antidepressants.