Ketamine relieves depression within hours

Ketamine relieves depression within hours
12:57 08 August 2006
NewScientist.com news service
Roxanne Khamsi

A drug used as a general anaesthetic may also work as a remarkably rapid antidepressant, according to a preliminary study.

The drug’s hallucinogenic side effects mean it is unlikely to be prescribed to patients, but it could pave the way to new faster-acting antidepressants, the researchers suggest.

Ketamine is used as an animal tranquiliser, but is perhaps better known as an illicit street drug, sometimes called “special K”. Now researchers have found the drug can relieve depression in some patients within just 2 hours – and continue to do so for a week.

One problem with current antidepressants is that they typically take weeks to kick in. Some studies have found that patients may face a high risk of suicide in the first week after starting an antidepressant treatment because of this lag time. So researchers have been searching for alternative drugs.

Fast acting

In 2000, a small study of eight people with major depression suggested that ketamine mitigated depression to a certain degree (Biological Psychiatry, vol 47, p 351).

Carlos Zarate, chief of the Mood and Anxiety Disorders Research Unit at the National Institute of Mental Health in Bethesda, Maryland, US and colleagues, set out to conduct a larger, more detailed trial of the drug’s antidepressant effects.

They analysed data from 17 participants, all whom suffered from moderate to severe depression and had failed to respond to at least two types of conventional drug treatments....