Ketamine found no better than placebo for depression in single experiment

New research could complicate our understanding of ketamine as a potential treatment for depression. The study found that people with depression who were given saline or ketamine before undergoing anesthesia for surgery experienced similar improvement in their symptoms afterward. The results suggest that at least some of the therapeutic benefits seen with ketamine may be attributable to the placebo effect, although further research is needed to confirm this.

Many studies found that low doses of ketamine, long used as a dissociative sedative and recreational drug, could also help treat depression and other mental health problems, and in a different waycurrent antidepressants. Some of these studies have also included the use of a placebo control for comparison, often considered the best method to determine whether a drug or vaccine actually works as intended (ideally, patients and the doctors who treat them do not know if they are in the treatment group or the control group).

The problem is that even a low dose of ketamine can cause short-term physical symptoms like dissociation or a trip, making it pretty easy to tell if you’re taking it, which then weakens any attempt to create a suitable placebo. for comparison purposes. Researchers at Stanford University therefore decided to conduct a unique experiment to better rule out this possibility.

Their study involved 40 people with major depressive disorder who were scheduled to undergo routine surgery requiring the use of general anesthesia. Half were randomized to receive a single dose of saline, the placebo, just before surgery, and the other half, a single dose of intravenous ketamine. Going dark would eliminate the chances of people taking a typical trip, researchers say. Then they observed the patients for up to three days.

At the end of the study, both groups reported the same average degree of improvement in their depression symptoms. People guessed correctly whether they took ketamine or the placebo less than half the time, or worse than chance, indicating that the blinding process actually worked.

In conclusion, a single dose of intravenous ketamine administered during surgical anesthesia had no greater effect than placebo in acutely reducing the severity of depressive symptoms in adults with major depressive disorder. declared the authors. wrote in their article, published this month in Nature Mental Health.

The study results are based on a small sample of patients and short follow-up, meaning any interpretations should be viewed with caution until more data are collected. And other researchers have already argued that the results might only suggest that surgery and anesthesia in general (which may include ketamine) may provide rapid relief of depression, not necessarily that ketamine has no therapeutic effect beyond placebo.

The authors say this hypothesis is unlikely to explain the results, since other research has not found a consistent link between surgery and improvement in depression (in some people even). experience worsening or new depression after an operation). But they are cautious about the implications of their work. On the one hand, they do not claim that ketamine should be considered a simple placebo when it comes to treating depression, nor that people with depression are somehow faking their illness.

To say it’s just a placebo really does a disservice to what a placebo is, study author Boris Heifets, an assistant professor of anesthesiology, said in a statement released by Stanford. I won’t feel better if I repeat it often enough, and that doesn’t imply that there was nothing wrong with the patient.

They hypothesize that people’s positive expectations might be at least part of the reason why ketamine appears to show these rapid benefits for some people. But even if that’s true, that doesn’t mean people don’t experience real, positive physical changes when they take it.

There is most definitely a physiological mechanism, something that happens between your ears, when you instill hope, Heifets said.