Relative Importance of Baseline Pain, Fatigue, Sleep, and Physical Activity: Predicting Change in Depression in Adults With Multiple Sclerosis.

Objective: To determine whether baseline levels of pain, fatigue, sleep disturbance, and physical activity measured at the initial assessment predicted the development of or improvement of depression 3.5 years later, while controlling for sex, age, and disease severity.
Design: Observational, longitudinal survey study.
Setting: A community-based population sample.
Participants: Adults with multiple sclerosis (MS) (N=489).
Interventions: Not applicable.
Main Outcome Measure: Primary outcome was classification of depression group measured using a Patient Health Questionnaire-9 cutoff score ≥10, indicating probable major depression.
Results: Fatigue severity (odds ratio, 1.19; 95% confidence interval, 1.12-1.26; P<.0001) and sleep disturbance (odds ratio, 1.06; 95% confidence interval, 1.02-1.10; P=.001) predicted probable major depression 3.5 years later among those not depressed at the initial assessment. An effect of age (odds ratio, .96; 95% confidence interval, .92-.99; P=.008) was found among those who developed depression, indicating that younger adults were more likely to develop depression. Pain, fatigue, sleep, and physical activity at baseline were not significantly associated with recovery from depression among those depressed at the initial assessment.
Conclusions: Fatigue and sleep may contribute to the development of depression. Clinical trial research targeting these variables to determine their influence on depression is warranted.
(Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.)