Potential New Option for Treatment-Resistant Depression

In a recent study, researchers found the medication esketamine may be a promising option for patients with treatment-resistant depression.

The drug was seen to rapidly and significantly improve symptoms in patients whose depression is unresponsive to current treatments, according to the study published by Biological Psychiatry. They discovered that esketamine, a component of ketamine, can improve symptoms in as little as 2 hours in some patients.

Selective serotonin reuptake inhibitors, a common antidepressant, can take up to 2 months to become effect, and even longer in other patients. Compared to the traditional time lag of months, this discovery may provide patients with a fast and effective option.

Although ketamine has been a promising antidepressant, there has yet to be a strategy created that maintains its efficacy. Other studies have shown that patients tend to relapse within 1 week after a single infusion of the drug.

In the current study, researchers randomized 30 patients with treatment-resistant depression to receive a low dose (0.2 mg/kg) or high dose (0.4 mg/kg) of esketamine or a placebo. Patients received 2 infusions during the double-blind portion of the study.

The double-blind phase was followed by a 2-week follow-up where patients could receive up to 4 additional open-label doses, according to the study. The earliest symptom relief was seen within 2 hours of the first infusion, and more than 60% of patients has improved symptoms within 3 days of treatment with esketamine.

This response rate is still higher than the response rate seen in traditional antidepressents after 6 to 12 weeks of treatment, which is 37 to 56%, the researchers wrote.

Approximately 17% of patients receiving the high dose of esketamine saw transient perceptual changes immediately after infusion, which subsided within 4 hours, according to the study. Patients in the placebo group did not respond to the treatment.

Clinical trials are currently being conducted to determine dosing, side effects, and establish the long-term safety of esketamine.

“The study shows clear benefits of the drug over placebo and suggests that the lowest of the 2 doses may be equally efficacious but also safer," said Murray Stein, MD, MPH, FRCPC, of the University of California San Diego and a deputy editor of Biological Psychiatry. “Though the mechanism of ketamine (and esketamine) antidepressant effects remains unclear, this study clearly demonstrates a benefit, at least in the short term, of this drug for treatment-resistant depression.”