Ketamine, an increasingly popular depression treatment, affects the brain like fentanyl and oxycodone, according to a study published in The American Journal of Psychiatry.
Here are six things to know:
1. Ketamine started as an anesthetic administered to children in hospital settings, but is increasingly prescribed as an off-label treatment for severe depression. Unlike most antidepressants and selective serotonin reuptake inhibitors, which take weeks to work, just one ketamine infusion or nasal administration can work within hours.
2. Researchers at Stanford (Calif.) University designed the study to treat patients with depression in two ways. The first group was given a ketamine infusion. The second group was given naltrexone, an opioid blocker, before receiving the ketamine infusion.
3. The analysis showed 7 out of 12 patients saw their depression symptoms decrease by about 50 percent after they received ketamine. The group that took naltrexone did not see a change in depression symptoms.
4. The study suggests ketamine's success in treating depression comes from the drug's interactions with the brain's opioid system. Ketamine's effect on opioid receptors could provide immediate, short-term relief of depression symptoms, researchers said.
5. The study's findings also suggest individuals taking ketamine for depression could be susceptible to abuse or addiction, according to study author Alan Schatzberg, MD, professor of psychiatry and behavioral sciences at Stanford University. While ketamine has a weaker effect on the brain's opioid receptors than more powerful drugs like oxycodone, "that doesn't mean it's safer," he told NPR.
6. Outside researchers noted further studies are needed to verify this finding.
"The results are quite intriguing," Carlos Zarate Jr., MD, chief of experimental therapeutics and the pathophysiology branch at the National Institute of Mental Health, told NPR. "However, this study is preliminary, and its results need to be replicated."