Cortisol responses to daily events in major depressive disorder.
OBJECTIVE
Abnormal responses of the hypothalamic-pituitary-adrenal (HPA) axis to stress are thought to be involved in the pathophysiology of major depressive disorder (MDD). The aim of the present study was to determine whether cortisol responses to negative and positive daily events in depressed participants (N= 47) differed from such responses in healthy participants (N= 39). We also examined the influence of clinical characteristics and possible gender differences in cortisol responses to events. Finally, the role of mood changes in mediating cortisol responses was assessed.


METHODS
Experience sampling methodology (self-reports of mood and events, with simultaneous saliva samples, 10 times each day for 6 consecutive days) and multilevel regression analysis were used to examine the relationship between events in daily life and salivary cortisol levels.


RESULTS
In contrast to healthy participants, depressed participants showed no increase in cortisol following negative events. Responses were even more blunted in depressed participants with a family history of mood disorders. Although the effects of negative events on cortisol responses appeared to be mediated by changes in mood, negative affect tended to be less closely associated with cortisol levels in depressed participants. Depressed women showed larger cortisol responses to negative events than depressed men. Positive events had no effect on cortisol levels in either group.


CONCLUSIONS
These results suggest that responses of the HPA axis to negative daily events and mood changes are blunted in MDD. Future studies will need to address whether these abnormalities disappear after clinical recovery.
D000222:Adaptation, Physiological; D000302:Adrenal Cortex / Q000378:metabolism*; D000328:Adult; D000339:Affect; D002940:Circadian Rhythm; D003866:Depressive Disorder / Q000503:physiopathology* / Q000523:psychology; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000032:analysis / Q000378:metabolism*; D007030:Hypothalamo-Hypophyseal System / Q000503:physiopathology; D008016:Life Change Events; D008297:Male; D008875:Middle Aged; D010913:Pituitary-Adrenal System / Q000503:physiopathology; D012463:Saliva / Q000737:chemistry; D012737:Sex Factors
D006854:Hydrocortisone