Risk of attempted and completed suicide appears to be elevated in people with Multiple Sclerosis (MS), however results have been inconsistent.
With risks ranging from 14 times higher to no greater risk at all, researchers led by Philip Brenner, of the Karolinska Institutet in Stockholm, Sweden, conducted a large prospective cohort study to examine the risk of attempted and completed suicide, and the effect of education level on suicide risk in MS patients.
The researchers identified 29 617 patients with MS through the Swedish National Patient Register and Swedish MS Register between 1968 and 2012. Each participant was matched with 10 Swedish residents without MS based on location, birth year, and sex (n=296 164). Data on attempted suicide, completed suicide, and suicide as cause of death was obtained via ICD coding and the Cause of Death Register, and education level was obtained from census data.
Overall, 19 318 women with MS and 9846 men with MS were included in the study. During the study, 423 people with MS attempted suicide and 114 completed suicide, for an incidence rate of 116.5 and 30.31 per 100 000 person years, respectively. Corresponding incidence rates among controls were 50.8 and 16.68. Mean age for attempted and completed suicide among people with MS and controls was 46.3 years vs 49.6 years, and 51.8 years vs 56.7 years, respectively. Notably, 37% of suicide attempts in the MS cohort occurred within 3 years of study entry, 57% within 5 years, and 87% within 15 years, while 29% of completed suicides occurred within 3 years, 53% within 5 years, and 86% within 15 years.
Accounting for the whole study population, women were found to be at higher risk for attempted suicide, while men were at higher risk for completed suicide. Both male and females with MS had a more than doubled risk of attempted suicide compared to controls when stratified by covariates. Adjusted risk for completed suicide was more than doubled for women and approximately 70% increased for men with MS. Education had an inverse association with suicide, with men and women with MS at a greater risk of attempted and completed suicide across all education levels. Notably, risk for attempted suicide was highest >20 years after study entry for patients with MS, compared to 5 years in controls.
“Amongst MS patients, the high prevalence of depression is most probably an important risk mediator,” the authors wrote. “Suicide ideation has been reported by 30% of MS patients. A third of MS patients who express suicidal intent have never received any psychological help.”
“To prevent suicidal behaviour, clinicians should clearly be aware of the overall increased risk amongst MS patients as well as possible risk factors,” they continued. “Brief screening questions for depression can identify most affected MS patients. Increasing cooperation with hospital consultative psychiatry units should be considered.”