Peripheral proinflammatory markers associated with ketamine response in a preclinical model of antidepressant-resistance

•Divergent ketamine (10mg/kg) response in FST for ACTH animals, deemed responders/non-responders.•Plasma CRP was significantly increased in ketamine responsive ACTH animals.•Plasma TNFα decreased in ketamine-treated ACTH animals; lowest in non-responders.•No significant difference in plasma IL-6 concentration across treatments observed.•Proinflammatory profile may be a useful biomarker for predicting ketamine response.