Beyond perceived stress: Hair cortisol is linked with cognition and fatigue in black and white patients with multiple...

Racial differences in Multiple Sclerosis (MS) and fatigue may be influenced by stress related biological and structural factors, yet the relationships among race, cumulative stress, cognition, and fatigue remain unclear.

This study examines the association of biopsychosocial markers of stress with cognition (Symbol Digit Modality Test - SDMT) and Fatigue domains.

Eighty-one patients with MS (79% female; 48% Black) and 41 controls (71% female; 27% Black) were enrolled. Participants completed self-report measures and cognitive testing (SDMT); a subset (N = 68) also provided hair samples for cumulative cortisol assessment.

Lower SDMT was associated with higher hair cortisol (B = -2.00, p = .016), MS (B = -8.72, p = .003), and being Black (B = -7.33, p = .007). Higher total fatigue (R² =.46, p < .001) associated with higher reported stress (B = 0.79, p < .001) and depression (B = 6.96, p < .001). Cognitive fatigue was associated with higher reported stress (B = 0.44, p < .001) and depression (B = 4.16, p < .001), but not MS. Patterns were consistent among women.

Findings indicate that biological and social indicators of stress (cumulative cortisol, MS diagnosis, and race) were associated with cognitive performance, whereas reported psychological indicators (perceived stress and depression) were associated with fatigue. These results highlight that objective and subjective measures of stress show distinct associations with MS related outcomes.