The suicide risk among Danish citizens with multiple sclerosis was compared with that of the general population. Changes over 45 years were also evaluated. The study was based on linkage of the Danish Multiple Sclerosis Registry to the Cause of Death Registry & comprised all 10,174 persons in whom multiple sclerosis was diagnosed in the period 1953-1996. 115 persons had died by suicide whereas the expected number of suicides was 54.2. The suicide risk among persons with multiple sclerosis was more than twice that of the general population. The increased risk was particularly high during the first year after diagnosis. (22 refs.)