Study: Ketamine acts like an opioid when used to help treat depression

Ketamine, an increasingly popular treatment for depression, works like an opioid to ease symptoms, according to a new study.

In the study published by the American Journal of Psychiatry, researchers from Stanford University found that ketamine works quickly and effectively by activating the opioid system in the brain. Dr. David Wolfe, the chief of ambulatory services in the psychiatry department at Brigham and Women’s Hospital said the new findings take research a step further to learn about the effects of using ketamine.

Wolfe explains that about a third of people seeking depression treatment are unresponsive to traditional medicine like Prozac, which is why they use ketamine. The drug is given through an IV infusion and can work in minutes whereas other drugs can take six to eight weeks to take effect. However, Wolfe said it’s only available through private practices and doctors are not sure if long-term use is safe.

“The mechanisms of ketamine and how it works in depression is still relatively not well understood. The study shows how much more we have to learn,” Wolfe said.

The findings of the study showed that without activating the opioid receptors in the brain, the antidepressant effects of ketamine were not enough to help patients.

Ketamine has not yet been approved to treat depression and therefore is not covered by insurance. Wolfe said one treatment can cost hundreds of dollars, and the effects of treatment usually wear off in about a week. He explained that ketamine has a history of abuse and there is always a risk of misuse when a drug is used repeatedly.

When it comes to the risk of addiction, Wolfe said there isn’t enough research to know for sure if patients can become addicted to ketamine treatments. He said the drug is also helpful in treating patients with suicidal thoughts and is often used in the emergency room with suicidal patients.

“I think in the field it (the study) challenges us to take a step back and ask the question, ‘what are our drugs doing?’ ” Wolfe said.