By Neil Trainis

The Royal Pharmaceutical Society president Claire Anderson has warned more research into the risks and effectiveness of ketamine as a treatment for depression is needed before it is made available on prescription.

Anderson told Independent Community Pharmacist the drug, which is licensed for use as an anaesthetic, carries risks for some patients such as those with psychosis and insisted research which has shown ketamine is beneficial in treating depression has been “limited.”

A study in the US, published last month, found ketamine had fewer long-lasting side-effects on patients without psychosis than electroconvulsive therapy (ECT) for “treatment-resistant major depression.”

A Swedish study last year concluded ECT was a “better option for the elderly and those with psychotic depression” but found “a standard dose of ketamine” was better for younger patients without psychotic depression.

Oxford University and Oxford Health NHS Foundation Trust consultant psychiatrist professor Rupert Mcshane said ketamine should be an option for patients with severe or drug-resistant depression who are being considered for ECT.

The Trust warned ketamine poses a serious health risk, such as severe bladder damage, when frequently used in high doses without medical supervision but suggested that in low doses and under medical supervision, it could be used off-label.

The Trust said patients may be reluctant to use ketamine to treat depression because National Institute for Health and Care Excellence guidelines make no reference to the drug but suggested NICE could authorise the intravenous use of ketamine in specialist clinics for patients being considered for ECT.

“I think if we were to get a license for intravenous ketamine as an alternative for people who have been considered for ECT, it would without doubt be a game changer," professor Mcshane told the BBC.

“Ketamine in low doses works in a different way to conventional antidepressants. And what is really exciting is that there is new data which suggests that it is as good as the best treatment for depression that we've got, which is ECT.”

However, professor Anderson said: “There is some limited evidence that Ketamine can have benefit to some patients for treating depression. However, there are also risks that Ketamine can make the situation worse for some patient groups due to the enhanced dissociation that Ketamine can produce, for example in patients with psychosis.

“As a result, more research on its effectiveness in clinical settings is needed. We fully support calls for further trials and investment in research to understand this further before widespread prescribing.”

Simon Bottle, a businessman from Kent who has had depression for 30 years, told the BBC that taking ketamine had been “game-changing” and said he was campaigning for it to be made available on the NHS.

The Royal College of Psychiatrists, however, also said more research on its effectiveness in clinical settings was needed.