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.