Cognitive performance in patients with burnout, in relation to diurnal salivary cortisol

This study investigated cognitive performance in patients with burnout, in relation to the flexibility of the hypothalamic-pituitary-adrenal (HPA) axis. Clinical cases with work stress-induced burnout (n=65), and demographically matched, healthy reference subjects (n=65), were given six neuropsychological tests and a self-rating scale for cognitive problems. Diurnal salivary cortisol was measured among burnout cases and an external reference group (n=174), including a dexamethasone suppression test (DST) among burnout cases. Compared with referents, the burnout group under-performed in a cognitive speed test (Wechsler Adult Intelligence Scale-Revised (WAIS-R) Digit Symbol), but not in any other test of sustained attention, episodic memory, or vocabulary. Burnout cases had considerably more subjective cognitive problems, but ratings were unrelated to test performance. Compared with referents, burnout cases had similar morning salivary cortisol levels and similar awakening response, but lower evening cortisol. Among burnout cases, lower diurnal cortisol variability was related to slower performance in several tests. The DST response showed no consistent relationship with any cognitive parameter. Hence, despite considerable subjective cognitive problems, the burnout group showed only a partial, mild deviation in cognitive performance. A flatter diurnal cortisol profile was related to lower cognitive processing speed, but diurnal cortisol pattern and DST response were normal, suggesting a maintained HPA axis flexibility.