A 75 mg/day clomipramine treatment was prescribed for 4 weeks to 92 outpatients with major depression at the Neuropsychiatric Clinic of the National University Hospital of Cotonou in Benin, West Africa. Among them, only 42 followed the treatment during the 4 weeks and had a clomipramine and desmethylclomipramine plasma level measure (gas chromatography technique). The rate of noncompliance appeared high: 10 patients had no trace and another 2 had only traces of anti-depressant in their plasma. For the remaining 29, a comparison with 29 Caucasian patients treated by clomipramine (the two samples are matched for sex and age, and the variables of weight, dosage and drug association are controlled) shows no significantly higher plasma levels in the Beninese sample.