BACKGROUND: Fatigue is a common symptom in the general population, as well as in several somatic conditions. Despite this, no review has yet examined the occurrence of fatigue across common mental disorders (CMD) such as mood disorders, anxiety disorders, personality disorders, and trauma and stressor related disorders. The objective of the review was to examine the prevalence of fatigue in patients with CMD, how fatigue when fatigue occurs in these populations, and it's relationshop with other outcomes. METHOD: We searched in 2026 Medline, PsychInfo, and Embase for studies reporting on fatigue in CMD and conducted a manual search of the included references. Two reviewers independently selected papers and extracted data. Eligible studies were on patients with CMD without somatic illness, that employed a measure designed to assess fatigue. We conducted and reported the systematic review following the PRISMA statement. The evidence was synthesized according to whether it reports on the prevalence of fatigue, or provides data on the temporal occurrence of fatigue in the trajectory of the disorders. RESULTS: We screened 7861 abstracts, and read full text on 393 papers and finally included 46 papers, of which 40 reported on prevalence. Most research concerned patients with mood disorders. Fatigue was found to be highly prevalent across CMD, with prevalences between 18% and 100%. Research suggests that fatigue can predict the onset of depression and that depression can predict the onset of fatigue. DISCUSSION: Fatigue is highly prevalent across patients with CMD and can therefore be regarded as a transdiagnostic symptom. A host of research suggests that fatigue in depression and anxiety can be explained by biological symptoms such as low-grade inflammation. Limitations includes high heterogeneity in the assessment of fatigue across included studies, and few instruments were validated for this population. CONCLUSIONS: The symptom of fatigue was found to be prevalent across samples of patients with CMD, which highlights it as a possible transdiagnostic treatment target.
Olsen et al. (Wed,) studied this question.