Abstract

An institutionalised 13 year old girl with psychomotor retardation suffered from an irregular sleep–wake pattern. Multiple measurements of urinary sulphatoxymelatonin (aMT6) concentrations were abnormally low, without any significant day–night differences. Administration of exogenous melatonin (3 mg) at 18:00 resulted in increased nocturnal urinary aMT6 concentrations and improvements in her sleep–wake pattern. Melatonin may help disabled children suffering from sleep disorders.