Cortisol Predicts Antidepressant Treatment Outcome, Memory Improvement, and Brain Response to Negative Emotions: The Importance of Aging

BackgroundStudies testing the relationship between cortisol levels, depression, and antidepressant treatment response have yielded divergent results suggesting the possibility of moderators of a cortisol effect. Several studies indicate that age may moderate the relationship between cortisol and psychopathology. In patients with Major Depressive Disorder (MDD), we studied the interactive effects of age and cortisol on predicting diagnostic status, improvement in mood and memory function with antidepressant treatment, and brain response to negative emotional stimuli.Methods66 unmedicated patients with MDD and 75 matched healthy controls had serum assayed at pre-treatment baseline for cortisol. Logistic regression was used to determine an association of age, cortisol and their interaction with MDD diagnosis. Thirty-four of the MDD participants (age range: 19-65 years; median: 36) underwent treatment with a selective serotonin reuptake inhibitor (SSRl) for 8 weeks. Clinician and self-ratings of depression symptoms, as well as tests of verbal and visual delayed recall were obtained at baseline and post treatment. Moderation analyses determined the effect of age on the relationship between baseline cortisol and treatment outcome. A separate sample of 8 MDD participants prospectively underwent fMRI neuroimaging and cortisol collection while viewing negative emotional faces.ResultsAge moderated the effects of cortisol on predicting MDD diagnosis (pConclusionsOur results indicate that age moderates the relationship between peripheral cortisol levels and (1) MDD diagnosis, (2) brain reactivity to emotional stimuli, and (3) antidepressant-associated improvement in depression and memory symptoms. These results indicate that previous disparities in the literature linking peripheral cortisol levels with depression characteristics and treatment response may critically relate, at least in part, to the age of the patients studied.