An open study of four dosage regimes of clomipramine (Anafranil)--10 mg t.d.s., 30 mg o.n., 25 mg t.d.s. and 75 mg o.n.--was performed in patients seen in general practice suffering from depression. The primary purpose of the study was to gather information on steady-state blood levels of unchanged drug and major metabolite. However, clinical assessments were also made on a seventeen symptom depression rating scale initially and after 1,2 and 4 weeks treatment and side-effects were assessed. Seventy patients were admitted to the study; forty-nine completed it. All four treatment groups showed significant improvement. The groups were small and no significant differences emerged between them. The best response of 77% improvement on total score after 4 weeks was obtained in the group of patients receiving 25 mg t.d.s. The patients on 30 mg daily showed a 67% response when this was divided and 65% when given singly. The worst response was obtained in the patients receiving 75 mg single dose (50%). Thirteen of the twenty drop-outs did so because of side-effects. Ten of these were in high dose groups. However, amongst patients who completed the study there was no difference in the side-effects observed in the four groups.