Objectives: To determine the impact of personality characteristics on feelings of fatigue in multiple sclerosis (MS) patients and to compare the results with the impact of bodily impairment.
Patients and methods: Eighty patients with definite MS (mean age 38.5 +/- 9.0 years, 62 females) were surveyed using questionnaires assessing fatigue experience and personality traits (German Freiburg Personality Inventory-Revised; FPI-R) and by clinical examination assessing the Expanded Disability Status Scale.
Results: Increased levels of "neuroticism", and "excitability" and decreased levels of "extraversion" were found to relate independent of fatigue scores (0.21 < beta < 0.52; 0.05 < P < 0.0001). The impact of these personality traits on fatigue (partial R2 ranging up to 0.32; 0.02 < P < 0.0001) was much higher than the impact of physical impairment (partial R2 ranging up to 0.04; not significant).
Conclusion: Our results support a psychological model of fatigue in MS. FPI-R-items over-weighted somatic sources of the fatigue syndrome in MS and may specifically relate to fatigue experience in chronical disorders.