Peripheral biomarkers in Repeated Ketamine Infusions Trial

Repeated ketamine infusions reduced depressive symptoms and suicidal ideation in patients with Major Depressive Disorder, but did not significantly change plasma C-reactive protein levels. Morning salivary cortisol changed over the course of treatment in a sex-dependent manner, suggesting that ketamine's effects on the endocrine system may differ between males and females. The findings indicate a need for further sex-specific research into how ketamine influences glucocorticoid expression to better understand its rapid antidepressant mechanisms.

Study at a glance

Abstract

Abnormalities in the endocrine and immune systems are well documented in patients with Major Depressive Disorder (MDD), however, the mechanisms by which the novel antidepressant treatment, ketamine, influences these physiological systems are unclear. This study examined the effects of repeated ketamine infusions on the endocrine and immune systems using the peripheral biomarkers C-reactive protein (CRP) and cortisol. While both depressive symptoms and suicidal ideation were reduced with repeated ketamine treatment, there was no significant change in plasma CRP levels throughout the clinical trial. Morning salivary cortisol did change throughout the clinical trial in a sex-dependent way. Further sex-specific investigation into ketamine's effect on glucocorticoid expression is needed to advance the knowledge of the underlying mechanisms of ketamine's rapid antidepressant effects to more effectively treat patients with depression.