Changes in cortisol secretion during antidepressive treatment and cognitive improvement in patients with major depression: a longitudinal study.

Objectives: We have previously reported that cognitive deficits are cross-sectionally associated with elevated cortisol in depressed patients. Here, we longitudinally examined if changes in cortisol secretion during treatment are associated with improvement of cognition.

Methods: Cognitive function and salivary cortisol levels were longitudinally examined in 52 patients with major depression before and after 3 weeks of standardized selective serotonin reuptake inhibitor (SSRI) and an add-on treatment modulating the mineralocorticoid receptor and compared to a healthy control group (n=50) matched for age, gender and years of education.

Results: Across add-on treatment groups, SSRI treatment reduced salivary cortisol in patients to levels of healthy controls (time×group interaction p=.05). In patients, reduction of cortisol significantly correlated with improvement in depressive symptoms (r=.52, p<.01), speed of information processing (r=.50, p<.01), and cognitive set-shifting (r=.34, p=.03). Improved depressive symptoms were only associated with improved attention and working memory.

Conclusions: Improvement of some cognitive domains during SSRI treatment was associated with decreasing cortisol secretion and was only to a lesser extent associated with improved depressive symptoms.