Ketamine therapy reduces depression, suicidal thoughts within hours

EXETER, England — Growing research on the anesthetic ketamine, also known as the club drug “Special K,” continues to suggest remarkable improvements for people struggling with their mental health. New research out of England shows the drug effectively reduces depression and suicidal thoughts shortly after being taken.

Scientists from the University of Exeter uncovered this evidence by analyzing the findings of 83 published papers that looked at the use of ketamine to treat major depression and bipolar depression.

The previous studies had found that in patients who suffered from either condition, ketamine reduced symptoms as fast as one to four hours after a single treatment and the effects lasted for up to two weeks. Some evidence suggests that repeated treatment with ketamine may prolong its positive effects, but in order to paint a clearer picture of how long, higher-quality research will need to be conducted.

Researchers also report that single or multiple doses of ketamine resulted in moderate to large reductions in suicidal thoughts. This staggering improvement was seen as early as four hours following the ketamine treatment. It lasted for an average of three days, with some patients relieved from suicidal thoughts for up to a week.

​​“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. 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,” says study lead author Merve Mollaahmetoglu in a statement.

There is promising evidence to suggest that patients with other psychiatric disorders like anxiety, post-traumatic stress disorders, and obsessive-compulsive disorders could also benefit from ketamine treatment. The papers further show that people with substance abuse issues also responded well to the treatment, which led to short-term reductions in craving, consumption, and withdrawal symptoms.

Mollaahmetoglu’s review adds to the growing field of research into the potential benefits of ketamine for conditions for which it is notoriously difficult to receive effective treatment. Her review included a combination of 33 systematic reviews, 29 randomized control trials, and 21 observational studies. The strong anesthetic drug ketamine is now known for its effects on depressive symptoms and suicidal thoughts, thanks to in-depth and an exhaustive list of analyses on the topic. This adds to the evidence suggesting that ketamine has antidepressant and anti-suicidal effects.

However, ketamine’s therapeutic effects for psychiatric conditions other than depression and suicidal thoughts are based on a small number of studies that did not randomize people. This means that the recorded effects now require a large randomized placebo-controlled trial. The authors pointed out a number of difficulties lurking within the research field that they think future studies should address. One issue is the bias created because the participants know they have been given ketamine, rather than a saline solution.

“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. 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. This effect may be better controlled by having active placebo-controlled trials, where the control group receives another drug with psychoactive properties,” notes Celia Morgan, the study’s senior author.

Some questions are still unanswered in the field of ketamine research, including how high a dose should be, the route of administration, and how many sessions are necessary. The benefits of psychotherapy in combination with ketamine treatment also require further research, as well as the best way to prepare patients for ketamine treatment and the setting in which it is delivered.

The study’s findings are published online in BJPsych Open.

South West News Service writer Georgia Lambert contributed to this report.