A study conducted on a small group of people showed that certain anesthetics are extremely efficient against depression, lifting the gloomy state in subjects in no more than 2 hours from the administration. Even if it seems rather odd the fact that anesthetics could treat what anti-depressants cannot, researchers that carried out the study proved it.

Scientists at the National Institutes of Health in Bethesda, Maryland showed that most of the patients suffering from depression who took the anesthetic pill were relieved in two hour time from symptoms. The beneficial action of the anesthetic lasted for an average period of 7 days.

The study was carried out on 18 participants that suffered from depression and could not be treated with any other antidepressant medication. The volunteers received random treatment with ketamine or placebo. Those who were administered intravenous doses of ketamine showed rapid symptoms improvement in the case of 71% of the patients. 29% of them were almost free from symptoms within 24 hours, while 35% of them presented improvement of symptoms even after several weeks' time. None of the patients involved in the study had any response to the placebo.

"People had tried six to seven antidepressants on average and had been ill for 30 years. The current episode was three years in duration. All people who went through this reported a tremendous relief of suffering," said the researchers.

The main problem with antidepressant medications is not their lack of effect, but the late onset of their action against the condition. Therefore, the possibility of using in parallel drugs with quick onset would be welcome in the case of all patients. This way, antidepressants or any other drugs with rapid action against depression symptoms would be used until the effect of real antidepressant treatment shows.

The anesthetic used in the study is called ketamine and proved to be effective, while other types of medicines failed to have any action against depression symptoms. Researchers warn, however, that despite its potency against depressive states, ketamine cannot be further used to treat depression as it can display a wide range of side effects, including psychosis.

The fact that currently available antidepressant medications took weeks before having effects on depression symptoms "was similar to the sound barrier. We felt we couldn't pass it," commented Dr. Carlos A. Zarate Jr., lead author of the study. "Now the sound barrier is broken. That doesn't mean you can get on the plane and take off right away, but it means it's possible that we can come up with a treatment that works very rapidly. That's down the road," he added.

The novelty of ketamine's action against depression symptoms relates both to the quick onset of its effect and to the fact that it targets a new brain system as compared to old antidepressant treatments. This is extremely important in helping medical experts to develop new types of antidepressant drugs that would work differently on brain.

"The relatively prolonged antidepressant effect that occurred with ketamine is remarkable considering its short half-life, which is approximately 2 hours. To our knowledge, there has never been a report of any other drug or (therapy) that results in such a dramatic, rapid and prolonged response with a single administration," researchers pointed out.

Dr. Richard A. Friedman, director of the Psychopharmacology clinic at Cornell University's Medical Center in New York City explained how the ketamine anesthetic worked on the brain: "Ketamine involves a particular system of the brain called glutamate. It's the main excitory neurotransmitter in the brain. It's novel because all antidepressants that are currently available work on neurotransmitters that are monoamines like dopamine and serotonin. That's the focus of the current antidepressant armamentarium."