Mediators and moderators of the stressor-fatigue relationship in nonclinical samples

Objective: Two cross-sectional studies examined statistical mediators and moderators of the stressful life event (SLE)-fatigue relationship. If such factors can be delineated, they might suggest possible avenues for improving current psychological treatments for fatigue. Methods: In Study 1, 281 (63 males and 218 females) participants, 18 to 70 years, completed a questionnaire asking about stressors, social support, demographics, and fatigue. In Study 2, 609 (225 males and 384 females) participants, 18 to 80 years, answered questions about the abovementioned variables, and sleep quality and use of sleep medications. Results: Younger age, more SLEs, and low social support satisfaction were found to be related to fatigue levels in Study 1. These results were replicated in Study 2, and, additionally, sleep disturbance (i.e., low sleep quality, use of sleep medications) was related to fatigue levels, while age was related to fatigue via the use of sleep medications. The SLE-fatigue relationship was found to be mediated through different mechanisms in males and females: social support dissatisfaction and sleep quality mediated the relationship in females, while sleep quality mediated the relationship in males. Conclusion: These results suggest that gender tailoring of psychological treatments may improve their effectiveness in treating fatigue, in particular, by targeting social support satisfaction in females and sleep hygiene in both sexes.