Ketamine Therapy Has Swift Short-Term Effect on Depression, Suicidal Thoughts

Symptoms of depression were reduced as quickly as 1 to 4 hours after a single treatment and lasted up to 2 weeks.

Treatment with ketamine therapy has a swift short-term effect on reducing the symptoms of depression and suicidal thoughts, according to a literature review led by the University of Exeter.

The study authors analyzed evidence from 83 published research papers and found that the strongest evidence surrounded the use of ketamine to treat both major depression and bipolar depression. Symptoms were reduced as quickly as 1 to 4 hours after a single treatment and lasted up to 2 weeks. Furthermore, some evidence suggested that repeated treatments could prolong the effects, although more high-quality research is needed to determine by how long.

Similarly, single or multiple doses of ketamine resulted in moderate to large reductions in suicidal thoughts, according to the study. This improvement was seen as early as 4 hours following treatment with ketamine and lasted an average of 3 days, and 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,” said lead author Merve Mollaahmetoglu, a PhD student at the University of Exeter, in the press release. “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.”

The effects of ketamine on depressive symptoms and suicidal thoughts are supported by multiple systematic reviews and meta-analyses, according to the researchers. There is also early evidence to suggest the potential benefit of ketamine treatment in other psychiatric disorders, including anxiety disorders, post-traumatic stress disorders, and obsessive-compulsive disorders. For individuals with substance use disorders, ketamine treatment also led to short-term reductions in craving, consumption, and withdrawal symptoms.

However, the effects of ketamine treatment on psychiatric conditions other than depression and suicidal thoughts are based on a small number of studies that did not randomize participants into different treatment arms, according to the researchers. These effects should be replicated in larger randomized placebo-controlled trials in order to verify them and provide stronger evidence, they further noted.

There are also several significant challenges in this field of research, which the authors said future studies should seek to address. One factor is the bias created when participants realize 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,” explained senior author Celia Morgan, PhD, in the press release. “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.”

Several important questions still need to be answered regarding ketamine treatment for depression and suicidal thoughts, including the optimal dose, route of administration, and number of doses, according to the study authors. Furthermore, the importance of ketamine’s acute subjective effects in its therapeutic benefits has not been fully explored. More research is needed on how to optimize patients’ preparation for the treatment and the setting in which it should be delivered.

REFERENCE

Ketamine therapy swiftly reduces depression and suicidal thoughts. News release. University of Exeter; December 23, 2021. Accessed January 21, 2022. https://www.exeter.ac.uk/news/research/title_890787_en.html