Salivary cortisol levels and the 2-year course of depressive and anxiety disorders.

Summary Introduction Depression and anxiety disorders have been associated with hyperactivity of the hypothalamic-pituitary adrenal (HPA) axis. However, lower cortisol levels have also been observed in depressed patients. Whether cortisol level predicts the course of these disorders has not been examined in detail. We examined whether salivary cortisol indicators predict the 2-year course of depression and anxiety disorders. Methods Longitudinal data are obtained from 837 participants of the Netherlands Study of Depression and Anxiety, with a DSM-IV based depressive and/or anxiety disorder at baseline. At baseline, seven saliva samples were obtained, including the 1-h cortisol awakening response, evening cortisol level and a 0.5 mg dexamethasone suppression test. At follow-up, DSM-IV based diagnostic interviews and Life Chart Interview integrating diagnostic and symptom trajectories over 2 years were administered to determine an unfavorable course. Results 41.5% of the respondents had a 2-year unfavorable course trajectory without remission longer than 3 months. Adjusted analyses showed that a lower awakening response was associated with an unfavorable course (RR = 0.83, p  = 0.03). No associations were found between evening cortisol or cortisol suppression after dexamethasone ingestion and an unfavorable course trajectory. Conclusions Among patients with depressive or anxiety disorders, a lower cortisol awakening response – which may be indicative of underlying exhaustion of the HPA axis – predicted an unfavorable course trajectory.