Sexual functioning in multiple sclerosis: Relationships with depression, fatigue and physical function

Background: Sexual dysfunction (SD) is common among people with multiple sclerosis, but there is limited information on its relationships. Objective: This national study examines the relationships between sexual function with demographic factors, physical function, fatigue and depression. Methods: Participants in the Trajectories of Outcomes in Neurological Conditions (TONiC) study completed the measures of fatigue, physical function and depression together with the Multiple Sclerosis Intimacy and Sexuality Questionnaire-15 (MSISQ-15), which covers sexual function (primary), symptoms that interfere with sexual function (secondary) and psychological issues (tertiary). All ordinal scores from the measures were converted to interval scale latent estimates via the Rasch model and used as single indicator latent variables in path analysis. Results: From 722 patients, 538 were sexually active of whom 431 (80.1%) answered questions on sexual functioning. Of these, only 18.5% reported no impact on any aspect of sexual function. Dysfunction was linked to disease subtype and Expanded Disability Status Scale (EDSS). Subtype influenced the relationship between symptoms and sexual function, which was fully mediated by psychological factors in secondary progressive patients. Depression was not directly associated with sexual functioning, but appeared as a consequence of the psychological issues associated with SD. Conclusion: SD is common among participants in this UK-wide study, and psychological aspects of SD contributed to depression.