Eight weekly subcutaneous injections of esketamine produced a 52.17% response rate and a 34.78% remission rate in 30 patients with treatment-resistant depression, with improvements in self-reported depressive symptoms sustained for up to six months. The open-label trial lacked a control group and had a small sample size, limiting causal interpretation and generalizability. Subcutaneous administration offers a cheaper, easier alternative to intravenous or intranasal routes with comparable plasma levels and fewer side effects.
Ketamine rapidly reduces depression symptoms in treatment-resistant depression, but its effects may be enhanced by combining it with psychotherapy. The drug induces neuroplasticity and psychological openness, which could help patients process emotions, restructure thoughts, and maintain improvements. However, research has not yet thoroughly examined whether adding structured psychotherapy to ketamine treatment provides additional benefits.