Melanosis after prolonged chlorpromazine therapy.

The effect of prolonged treatment with chlorpromazine in high dosage, on skin melanin, was measured by reflectance spectrophotometry. Whites and Blacks of both sexes were tested in this study which compared 201 chlorpromazine-treated, chronic psychiatric patients (predominantly schizophrenics) and 161 controls. The treated patients generally had significantly higher concentrations of melanin in the skin than the controls. These differences were particularly marked in the female groups and in the exposed areas of the White groups. The aetiology of the melanosis is discussed.