Club drug is surprise antidepressant

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

  • E-Mail
By  Joanne Bladd Published  September 27, 2006

A drug used as a general anaesthetic may also work as a remarkably rapid antidepressant, according to a preliminary study. Ketamine is used as an animal tranquiliser, but is more widely known as an recreational drug. In a small study of 17 patients, researchers found the drug relieved depression in some subjects within two hours, and remained effective for up to a week. The National Institute of Mental Health (NIMH) team, led by Carlos Zarate, chief of the Mood and Anxiety Disorders Research Unit, injected patients with either a very low dose of ketamine or a placebo of saline solution. Trial participants were all depression sufferers who had tried an average of six treatments that had failed. The researchers then measured their levels of depression minutes, hours and days after the dose was given. According to Dr Zarate, “Within 110 minutes, half of the patients given ketamine showed a 50% decrease in sypmtoms.” This rating was gauged in accordance with the Hamilton Depression Rating Scale. In previous trials for established, long-acting antidepressants, only 63% of participants experience this same reduction in symptoms after eight weeks of medication. By the end of day one, Zarate says, 71% had responded to the drug, and 29% of the patients were nearly symptom free. The effects of one dose lasted for a least a week in more than one-third of participants. The study results were published in Archives of General Psychiatry. Dr Thomas Insel, Director of NIMH, commented: “To my knowledge, this is the first report of any medication or other treatment that results in such a pronounced, rapid, prolonged response with a single dose. “These were very treatment-resistant patients.” Unlike most anti-depressants, which work by boosting serotonin or dopamine levels, ketamine reduces the effects of another neurotransmitter, called glutamate. The team believe this may explain the drug’s faster action, and may suggest an alternative pathway for other antidepressant drugs in development. Ketamine in its current form would not be appropriate for medication, because of its hallucinogenic properties. These were experienced by the “vast majority” of participants, Zarate says. The team is now exploring compounds derived from ketamine to see if they can find one that offers the same antidepressant effect without causing hallucinations.

Add a Comment

Your display name This field is mandatory

Your e-mail address This field is mandatory (Your e-mail address won't be published)

Security code