A classificatory system for mental disorders in the elderly proposed by Roth in 1955 was examined in a contemporary population. Ninety per cent of patients could be allocated to the five psychosyndromes originally defined. Examination of outcome in the present sample, at six month and two years, showed important differences. The outlook for patients with paranoid psychoses showed an improvement though for those with affective illness (at 2 years) there was little change. Of special importance was the increased long-term survival of very elderly female patients with senile dementia. This, in conjunction with the general rise in admissions for mental disorders in the aged over the past 25 years, has considerable implications for the future development of psychiatric services for the elderly mentally ill.