Researchers in the UK gave ketamine to severely depressed patients and found positive results from it.
Ketamine is a licensed medical drug, used as an anesthetic and to relieve pain, but it is also used as a recreational drug, sometimes nicknamed “special K.”
The researchers tested ketamine on 28 people with major depressive disorder and found the drug quickly helped relieve the condition for some and made a few of them completely well for up to several weeks.
Although many relapsed within a day or two, almost a third of them felt a benefit which lasted at least three weeks and 15 percent did not relapse for more than two months.
“We’ve seen remarkable changes in people who’ve had severe depression for many years that no other treatment has touched,” said Rupert McShane, a consultant psychiatrist and researcher at Oxford University who led the study. “It’s very moving to witness. Patients often comment that 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.”
“It’s dramatic and it’s exciting, and it is a novel mechanism. But it’s not about to become a routine treatment,” added McShane.
“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. We now need to build up clinical experience with ketamine in a small number of carefully monitored patients,” McShane said. “By trying different infusion regimes and adding other licensed drugs, we hope to find simple ways to prolong its dramatic effect.”
Many ketamine abusers report severe bladder problems and cognitive impairment related to their drug use. However, the researchers did not find evidence of these side effects in their trials, maybe because such a low dose was used.
The study was published in the Journal of Psychopharmacology on Thursday. Patients with treatment-resistant depression were given either three or six intravenous infusions of 0.5mg/kg of ketamine, each lasting 40 minutes, at Warneford hospital’s ECT clinic in Oxford.
Four to seven days after the final infusion, eight of them had responded to the treatment, measured by their depression “score” falling by 50% or more, of whom four were in remission.
Among those who responded to ketamine, the duration of benefit varied widely, from 25 days to eight months, with the median 2.3 months.
One of the reasons the drug is thought to work is that it has a direct impact on the subgenual anterior cingulate, the part of the brain where overactivity is seen in people with depression.
Research teams have been studying the potential for ketamine use in depression, since many patients with severe depression fail to respond to any current available antidepressants such as Prozac or Seroxat. Some antidepressants can take 10 or more days to take effect.
Johnson & Johnson is developing a drug called esketamine. Currently it’s in mid-stage trials and has said its results so far have been promising.