The party drug ketamine could be the answer to treating even seemingly untreatable cases of depression, according to a growing body of research.
A new study published this week in the Journal of Psychopharmacology found that approximately one-third of patients with what researchers referred to as "treatment-resistant depression" experienced a significant mood improvement after being treated with up to six intravenous ketamine infusions over the course of several weeks.
"Three days after the last infusion, the depression scores had halved in 29 percent of the patients," said a news release on the study, which was conducted by United Kingdom researchers at Oxford Health NHS Foundation Trust and the University of Oxford. "In those that responded to the treatment, the duration of benefit varied widely, lasting between 25 days and 8 months"
Lead researcher Dr. Rupert McShane said some of the patients involved in the study had lived with depression for 20 years. "It really is dramatic for some people," he told the BBC of the improvements seen in some of the study's subjects. "It's the sort of thing really that makes it worth doing psychiatry, it's a really wonderful thing to see."
McShane's study had a small sample of just 28 patients, but his isn't the first to link ketamine -- a Schedule III drug known on the street as "Special K" or simply "K" -- with effective treatment for depression.
Several studies conducted in the past decade or so supported the idea that ketamine could treat major depression effectively and quickly. In 2012, for example, researchers from Yale University said ketamine seems to "produce rapid antidepressant responses in patients who are resistant to typical antidepressants."
"It's exciting," Ron Duman, co-author of that study, told NPR at the time. "The hope is that this new information about ketamine is really going to provide a whole array of new targets that can be developed that ultimately provide a much better way of treating depression."
Another study, conducted by researchers at Houston's Baylor College of Medicine and New York's Mount Sinai School of Medicine, had similar results. Published last year, the study -- said to have been the largest of its kind -- found that 64 percent of patients who had been treated with ketamine reported fewer depression symptoms.
Though ketamine's purported ability to relieve depression for some individuals has been welcomed by many experts as a possible step forward in the search for better treatments for depression, there are many health risks associated with the drug.
Commonly used as an anesthetic for both humans and animals, ketamine is described by the U.S. Drug Enforcement Administration as a dissociative anesthetic with hallucinogenic properties. Some users say that, when taken at high enough doses, the drug can induce a terrifying out-of-body experience known commonly as a "K-hole." The drug is also known to cause anxiety, amnesia and cognitive difficulties.
Medical experts have strictly warned against self-medicating with ketamine. In clinical studies, the drug is typically administered only in small doses, and patients are always supervised closely. Even then, some patients have been known to exhibit unpleasant side effects.