Factors Associated with Antidepressant Effects of Ketamine: A Reanalysis of Double-Blind Randomized Placebo-Controlled Trial of Intravenous Ketamine for Treatment-Resistant Depression
Pharmacopsychiatry July 30, 2023 Kengo Yonezawa, H. Uchida, T. Yatomi et al. 8 citations
Later age of depression onset is linked to a better treatment response three days after intravenous ketamine in adults with treatment-resistant depression. In a placebo-controlled, double-blind, randomized trial of 31 patients (13 women; average age 48.4 years), logistic regression showed that older age at onset positively correlated with response after three days. No associations were found between response and age, sex, baseline depression severity, or dissociative symptoms. Multiple regression found no factors significantly correlated with change in depression scores. The authors suggest that earlier onset may impair glutamatergic signaling and neuroplasticity, reducing ketamine's effectiveness.