BACKGROUND: Mental disorders and suicidal behavior are common in patients with multiple sclerosis (MS), they also carry a higher risk of disability pension (DP). Our aim was to investigate if DP and other factors are associated with psychiatric disorders and suicidal behavior among MS patients, and whether DP is a stronger risk indicator among certain groups.

METHOD: A prospective population-based cohort study with six-year follow-up (2005-2010), including 11 346 MS patients who in 2004 were aged 16-64 and lived in Sweden. Incidence rate ratios (IRR) with 95 % confidence intervals (CI) were calculated.

RESULTS: MS patients on DP had a modestly higher risk of requiring psychiatric healthcare, IRR: 1.36 (95 % CI: 1.18-1.58). MS patients with previous psychiatric healthcare had a higher IRR for both psychiatric healthcare and suicidal behavior; 2.32 (2.18-2.47) and 1.91 (1.59-2.30), respectively. DP moderated the association between sex and psychiatric healthcare, where women on DP displayed higher risk than men, X(2) 4.74 (p = 0.03).

CONCLUSION: The findings suggest that losing one's role in work life aggravates rather than alleviates the burden of MS, as MS patients on DP seem to have a higher need for psychiatric healthcare, especially among women; which calls for extra awareness among clinicians.