Scientists have successfully conducted the first ketamine intravenous infusions in people as a treatment for severe depression.
Ketamine is a powerful form of anesthetic usually administered to animals. However, it has been used as a "date-rape" drug because high dosage of it can cause hallucinations and difficulty in movement. It was listed as a controlled substance in the United States in 2009.
A new study conducted by researchers from the Oxford Health NHS Foundation Trust and the University of Oxford suggested that ketamine can be used as an antidepressant cure for people who have severe depression and have not responded to any of the existing treatments. Treatment for depression may last for years, requiring the patient to take antidepressants and undergo multiple therapies.
In the study, 28 participants diagnosed with treatment-resistant depression were subjected to ketamine treatment for three weeks. They received three to six infusions, each lasting for 40 minutes in the ECT room of Warneford hospital. Memory tests were also conducted to see if there is memory loss, a common side effect of depression treatments.
The patients responded to the treatment after the second infusion and after three days of the third or sixth infusion; depression rates decreased by 50 percent for 29 percent of the patients. The ketamine treatment did not induce any problems with bladder and memory although some patients reported feeling anxious while receiving the infusions. During the study, some patients expressed suicidal tendencies but depressive ideas have decreased overall.
"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," principal investigator Dr Rupert McShane explained in a press release.
This study was published in the April 3 issue of Journal of Psychopharmacology.
