Ketamine, a hallucinogenic party drug originally intended as an anesthetic, could be used to help people with treatment-resistant depression, according to a new study.
Scientists at Oxford University found that in a study of 28 patients who had failed to respond to talk therapy and multiple antidepressants, once- or twice-weekly injections of the drug over a three-week period provided immediate and substantial results for some of the cases.
“We've seen remarkable changes in people who've had severe depression for many years that no other treatment has touched. It's very moving to witness,” said Dr. Rupert McShane, a consulting psychiatrist and researcher at the university’s department of psychiatry. “Patients often comment that the flow of their thinking seems suddenly freer. For some, even a brief experience of response helps them to realize that they can get better, and this gives hope.”
The new study, which was released Thursday, builds on prior work on the effects of the drug – known in club circles as “Special K” – on people with depression.
In 2000, a study led by the Yale School of Medicine found that just a single dose of ketamine could have an antidepressant effect within three days — a far shorter time frame than some established antidepressant drugs.
Ronald S. Duman, a psychiatry professor at the Yale School of Medicine whose research has focused on antidepressants, explained that ketamine appears to affect the brain's receptors for a neurotransmitter called glutamate, which has a strong role in mediating the brain's synaptic impulses.
Duman's research has shown that ketamine works to develop more connections between nerve cells in the brain, reversing the effects of depression, he explained.
“People who are really sick and even suicidal can get better almost immediately,” he told Al Jazeera. Duman added that for people who have severe depression that is otherwise treatment-resistant, the apparent breakthrough could be “potentially lifesaving.”
The Oxford University study found that 29 percent of the people who took two doses of the drug had an improvement in their depressive symptoms that lasted at least three weeks, and 15 percent of the subjects experienced alleviation of symptoms for two months.
A handful of patients had side effects like anxiety or vomiting, and most patients experienced some short-lived dissociative effects — meaning they felt disconnected from their bodies — but only when the ketamine was being administered intravenously. The results were published in the Journal of Psychopharmacology.
A short-acting anesthetic often used in veterinary medicine, ketamine became a popular recreational drug at clubs and raves in the 1990s. It gives users a hallucinatory high that lasts up to 60 minutes, according to the Drug Enforcement Administration (DEA).
It is approved for medical use but has the potential to be addictive, doctors warn.
The study's authors also cautioned that large doses of ketamine taken recreationally may interfere with proper bladder and cognitive functioning.
“Those who regularly abuse high doses of ketamine recreationally demonstrate long term semantic and episodic memory deficits, which continue after cessation of the drug,” the authors wrote. “Those are potentially relevant when considering repeated administration of ketamine to treat patients suffering from chronic depression.”