Predictors of Antidepressant Use Among People With Multiple Sclerosis.

Objective: Anxiety and depression are common among individuals with multiple sclerosis (MS) but are often undertreated. Little is known about factors that influence the odds of antidepressant treatment for MS. The authors aimed to identify predictors of antidepressant use among people with MS.

Methods: A retrospective chart review was undertaken for a consecutive sample of 315 individuals with MS attending a tertiary neuropsychiatry clinic in Toronto. Predictor variables of antidepressant use included age, sex, MS duration and subtype, disease-modifying therapy use, psychotropic medication use, Expanded Disability Status Scale (EDSS) score (for neurological disability), Hospital Anxiety and Depression Scale subscale score (for anxiety and depression), and the abbreviated five-item Modified Fatigue Impact Scale (MFIS-5) score (for fatigue). Independent predictors of antidepressant use were identified with backward stepwise regression analyses (p<0.05).

Results: Participants' mean±SD age was 45.5±11.4 years, 74% were female, the mean EDSS score was 2.8±1.9 out of 10.0, and 70% had a relapsing-remitting subtype of MS. Psychotropic medication use such as antipsychotics and anxiolytics (OR=1.77, p<0.01), increased EDSS scores (OR=1.20, p<0.01), and increased MFIS-5 scores (OR=1.11, p<0.01) independently predicted antidepressant use.

Conclusions: Polypharmacy, neurological disability, and fatigue may increase the odds of antidepressant use among people with MS. These findings clarify differences between people with MS who use or do not use antidepressants, shedding light on the factors that may influence antidepressant use among people with MS.