A systematic review of dozens of research papers has found that ketamine therapy has a quick, short-term effect of reducing depression symptoms and suicidal thoughts, making it a promising mental health treatment alternative.
The U.K’s University of Exeter, in collaboration with the University of British Columbia, examined 33 systematic reviews, 29 randomized control trials, and 21 observational studies.
In a paper published in the British Journal of Psychiatry Open, they found the strongest evidence around the use of ketamine to treat both major depression and bipolar depression, with symptoms reduced as quickly as one to four hours after a single treatment that lasted up to two weeks.
The review also found that single or multiple doses of ketamine resulted in large reductions in suicidal thoughts, from four hours after the treatment and onward. The effect lasted on average three days, and up to one week, according to a news release.
“Our research is the most comprehensive review of the growing body of evidence on the therapeutic effects of ketamine to date. Our findings suggest that ketamine may be useful in providing rapid relief from depression and suicidal thoughts, creating a window of opportunity for further therapeutic interventions to be effective,” said lead author Merve Mollaahmetoglu in the release.
“It’s important to note that this review examined ketamine administration in carefully controlled clinical settings where any risks of ketamine can be safely managed.”
The review found early evidence of a potential benefit from ketamine therapy for other psychiatric disorders such as anxiety disorders, post-traumatic stress and obsessive compulsive disorders.
“Moreover, for individuals with substance use disorders, ketamine treatment led to short-term reductions in craving, consumption and withdrawal symptoms,” the release states.
However, the researchers note that some of the studies on ketamine therapy for psychiatric disorders other than depression and suicidal thoughts were done in small numbers and were not randomized. The review calls for those studies to be replicated in larger, randomized placebo-controlled trials which are considered the gold standard in science.
But placebo trials with ketamine therapy come with their own hurdles.
“We’re finding that ketamine may have promising benefits for conditions that are notoriously hard to treat in clinic. We now need bigger and better-designed trials to test these benefits,” said senior study author Celia Morgan in the release. “For example, due to ketamine’s unique subjective effects participants may be able to tell whether they have been given ketamine or a saline solution as the placebo, potentially creating an expectation about the effects of the drug.”
Researchers aim to continue researching ketamine therapy to determine the optimal dose, the best way to administer the drug, which setting is optimal for treatment and how to optimize patients’ preparation for the therapy.