Circulating Cortisol in a Cohort of Depressive Patients

It has long been suspected that the hypothalamic pituitary adrenal (HPA) axis plays a role in the pathophysiology of depression. Whether this association exists or not, and if it does, the degree of its significance, remain highly disputed. The issue is further complicated as no consensus currently exists on cortisol sampling timepoints or methods. Our study aimed to evaluate HPA functionality by evaluating plasma cortisol levels in a cohort of patients diagnosed with Major Depressive Disorder (MDD). We enrolled 96 subjects admitted for a major depressive episode and tested serum cortisol levels for 80 of them. We found that only 15 (12%) had values that were outside the normal reference range, with 14 of these being below the normal threshold. We also interviewed the patients and obtained self-reported information regarding previous depressive episodes, treatment administration, anxiety, suicidal ideas and suicidal gestures. Our study did not find a significant association between cortisol levels and the number of previous depressive episodes, the presence of feelings of anxiety, suicidal ideas or suicidal gestures. While our cohort did not find an association between cortisol levels and depression other authors have reported significantly different results and as such, more research is needed in order to establish or infirm this hypothesis.