Pretreatment cortisol levels predict posttreatment outcomes among older adults with depression in cognitive behavioral therapy.

Previous studies suggest that individuals with elevated levels of cortisol (the "stress hormone") could be particularly resistant to treatment for depression. However, most of these studies have been conducted in the context of antidepressant medications, and no study has examined pretreatment cortisol levels as a predictor of treatment outcomes among older adults with depression in cognitive-behavioral therapy (CBT), despite the relevance of this population for such a research question. The current study includes 54 older adults with depression who provided salivary cortisol samples at baseline and completed measures of depression at pretreatment and posttreatment, following a 12-week course of CBT. Structural equation modeling results suggest that those with higher daily outputs of cortisol and flatter diurnal slopes were less likely to benefit from CBT-a finding which if replicated could have important implications for clinical practice and future research.