Twenty-four out-patients with established multiple sclerosis (MS) who had been neurologically assessed underwent detailed psychiatric, cognitive and social assessments. Depression was associated with significant cognitive impairment and with social stress but not with degree of neurological impairment, specific neurological symptoms, disability or handicap. It is suggested that depression in relapsing-remitting MS may arise when cognitive deficits cause problems in occupational performance and impinge on close personal relationships.