Party drugs such as ketamine clearly deliver a euphoric effect for club-goers and ravers, but can the narcotic actually relieve depressive symptoms? Researchers from the University of Oxford have concluded the first study in the UK to test the effects of the drug on individuals suffering from depression, and the results may surprise you.

According to the National Institute of Drug Abuse, ketamine, also known as “special K,” is a dissociative anesthetic developed for use in a veterinary setting. This licensed medical drug is primarily used for pain relief and is sometimes referred to as a horse tranquilizer. The Oxford research team expects ketamine to be reclassified as a Class B banned substance.

“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,” consultant psychiatrist from Oxford University, Dr. Rupert McShane, said in a statement. “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.”

McShane and his colleagues from Oxford University’s Department of Psychiatry recruited 28 patients with diagnosed depression who had no response to other forms of treatment. Each patient received three to six intravenous ketamine infusions, which included over 80 milligrams per dose. The research team performed memory tests on each patient a couple of days after receiving their final dose and asked the individuals to update their mood symptoms on a daily basis.

By the third day following the patient’s last infusion, 29 percent of the group reported that their depression score had been cut in half. Of the patients who did confirm the drug’s antidepressant effect, 29 percent took at least three weeks to relapse, while 15 percent reported benefits lasting more than two months. The controlled doses of ketamine did not seem to cause cognitive memory loss or bladder side effects.  

“Ketamine is a promising new antidepressant which works in a different way to existing antidepressants. We wanted to see whether it would be safe if given repeatedly, and whether it would be practical in an NHS setting. We especially wanted to check that repeated infusions didn't cause cognitive problems.”

Certain adverse side effects were reported over the course of the study including a few patients who became sick and one who fainted. Other patients experienced “dissociative” effects, such as a disconnection with their body or a distorted perception of reality, although these symptoms were generally short-lived. Few patients suffered from anxiety while receiving the infusions, and some refused to finish the study after feeling they would not benefit.

“Intravenous ketamine is an inexpensive drug which has a dramatic, but often short-term, effect in some patients whose lives are blighted by chronic severe depression,” McShane added. “We now need to build up clinical experience with ketamine in a small number of carefully monitored patients. By trying different infusion regimes and adding other licensed drugs, we hope to find simple ways to prolong its dramatic effect.”

 

Source: Diamond PR, Farmery AD, McShane R, et al. Ketamine infusions for treatment resistant depression: a series of 28 patients treated weekly or twice weekly in an ECT clinic. Journal of Psychopharmacology. 2014.