Our brains are constantly creating beliefs about ourselves, the world, and the future. They help us navigate reality. But in depression, this mechanism fails: negative thoughts become fixed, and it seems impossible to change them.
What if there was a way to restart this process?
Ketamine is a quick mood switch
Conventional antidepressants work slowly - it takes several weeks to notice the effect. But ketamine, which used to be used as an anesthetic, works quite differently. It affects NMDA receptors and can significantly change a person's mental state within a few hours after administration.
Patients with severe depression that did not respond to other treatments often described this effect as a "change in perspective." Negative beliefs that had seemed unchanged for months or years suddenly lost their power. Some even said that their thoughts no longer seemed "theirs".
Depression as a trap of negative beliefs
According to WHO estimates, more than 280 million people worldwide suffer from depression, and 700,000 people lose their lives to suicide every year. One of the most dangerous symptoms is the belief that the situation will never change, that you are worthless or doomed to failure.
These thoughts work on the principle of feedback: if a person believes that he or she is not accepted in society, he or she begins to avoid others. This, in turn, further increases the feeling of isolation. This creates a vicious circle that is difficult to break.
What did the research show?
Scientists conducted an experiment: they asked depressed patients to estimate the likelihood of negative events in their lives (for example, an accident or a dog attack). Then they were informed of the real statistical risks and given the opportunity to reconsider their assessment.
For healthy people, this works simply: they easily accept positive news and adjust their beliefs. But people with depression remained "deaf" to good news, continuing to believe the worst.
But here's what happened after ketamine was administered: within four hours, the patients began to respond to positive information in the same way as healthy people. Their brains became more flexible, and they learned to update their beliefs again.
What's next.
Scientists are still studying how exactly ketamine changes brain function, but there are suggestions that it helps restore the balance between neural processes responsible for predicting the future and emotional plasticity.
These discoveries could dramatically change the approach to treating depression. Ketamine not only relieves symptoms, but also seems to "reboot" the way of thinking. This gives hope for new therapies that combine pharmacology with psychotherapy.
Similar research is already underway with other psychedelics, such as psilocybin. Could it be that the future of psychiatry lies in the ability to change our beliefs in the same way we change our thoughts?
Perhaps the answer is closer than we think.
Based on the study "Evaluation of Early Effects of Ketamine on Belief Renewal Bias in Patients with Treatment-Resistant Depression" recently published in JAMA Psychiatry.
