Associations between symptom severity and gray matter volume in exhaustion disorder

Chronic stress conditions, such as clinical burnout and exhaustion disorder (ED), represent a substantial and increasing individual and societal burden. Both short- and long-term effects of these conditions on the brain are poorly understood, however. We therefore initiated the PROMUS project, a high-powered longitudinal brain imaging study of ED. Here, we present the cross-sectional baseline results from the analysis of associations between symptom severity and regional gray matter volumes We used magnetic resonance imaging (MRI) and voxel-based morphometry (VBM) to assess associations between symptom severity and regional gray matter volumes in 300 participants on sick leave due to ED. Symptom severity was measured using the total score of the Shirom-Melamed Burnout Questionnaire (SMBQ), and the subscales Physical exhaustion, Listlessness, Cognitive weariness and Tension. All analyses were adjusted for age, intracranial volume, salary, education and sick leave duration. Total SMBQ scores and Physical exhaustion were negatively associated with gray matter volume in the ventromedial prefrontal cortex/orbitofrontal cortex, and right insular cortex. Listlessness was negatively associated with gray matter volume in the bilateral hippocampi, right insular cortex, left cingulate cortex and right middle temporal gyrus. These associations remained significant after adjusting for symptoms of depression, except for the insular cortex. No significant associations were observed for Cognitive weariness or Tension. These results support a link between symptom severity and gray matter alterations of brain circuits involved in stress in ED and suggest that these effects may extend beyond those attributable to depressive symptoms.