For those suffering from seemingly untreatable depression, the answer could lie in the drug ketamine. The drug, which became popular recreationally in the mid-noughties, is mainly used as a medication to help start and maintain anaesthesia. It is often referred to as a "horse tranquilliser" due to its use as a pain management drug during equine surgery.
Now, experts in a new paper, have added further weight to evidence that ketamine could be used to combat depression saying that "ketamine use for severe, treatment-resistant depression does not violate ethical principles."
The paper was released yesterday and was authored by Professor Ilina Singh from Oxford University, drugs expert Professor David Nutt and psychiatrist Rupert McShane. It referred to ketamine's "innovative potential" to treat severe depression and made much of a 2000 study that found that over a course of six years, 71% of patients with treatment-resistant depressive disorders had "greater than 50% reductions in depressive symptoms".
However, they warn that we must proceed with caution. Clinicians "must take steps to ensure that guidelines for good practice are enacted" they wrote "that all experimental and trial data are made available through national registries, and that the risk potential of ketamine treatment continues to be monitored and modelled."
Ketamine misuse has many negative long-term side effects including "ketamine bladder" - an issue caused by damage to the lining of the bladder which means it shrinks, causing the sufferer to go to the toilet more often and, sometimes, find themselves in huge amounts of pain and being unable to go. In some cases, the bladder has to be removed.
Ketamine is thought to work on depression (and again, McShane is keen to stress that it is for "severe, untreatable depression") by reducing what he called "hyperconnectivity" between the "emotional regulation area" of the brain and other areas.
Louise, a 36-year-old former nurse who took part in the trial, said: “In depression and anorexia you get a constant, overwhelming bombardment of negative intrusive thoughts surging through your brain. “Ketamine slows this down so you can fight back. I’m the most stable I've been in years."