Fatigue in multiple sclerosis: reciprocal relationships with physical disabilities and depression.
OBJECTIVE
To explore relations of fatigue, physical disabilities, and depression in patients with multiple sclerosis (MS) cross-sectionally and over time.


METHODS
Ninety-eight MS patients were interviewed twice at an interval of a year. Relationships of physical and mental fatigue, and reduced activity and motivation with depression and physical disabilities were established cross-sectionally by regression analyses and longitudinally by structural equation modelling.


RESULTS
Cross-sectionally, physical fatigue was related with physical disabilities, and mental fatigue was associated with depression. Prospectively, physical fatigue was a predictor of the physical disabilities of a year later. The reverse relationship of physical disabilities predicting the physical fatigue of one year later was, however, not significant, while depression predicted this physical fatigue and reduced activity of a year later. Depression did not predict the later mental fatigue nor was depression predicted by preceding fatigue experiences.


CONCLUSIONS
Fatigue in MS should be studied over time as relationships of fatigue with physical and mental health change during the course of a year. Moreover, differentiating in fatigue experiences sheds light on the relationship of fatigue with physical and mental health.
Schreurs
Karlein M G
KM
Department of Health Psychology, Utrecht University, PO Box 80140, 3508 TC Utrecht, The Netherlands. k.schreurs@fss.uu.nl
de Ridder
Denise T D
DT
Bensing
Jozien M
JM
D000328:Adult; D003430:Cross-Sectional Studies; D003863:Depression / Q000209:etiology / Q000523:psychology*; D006233:Persons with Disabilities / Q000523:psychology*; D005221:Fatigue / Q000209:etiology* / Q000523:psychology*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000150:complications* / Q000523:psychology*