Dance club drug 'can have magical role in relieving depression'

The drug quickly induces the regeneration of synaptic connections between nerve cells in the brain, a study has shown.

Understanding the way the drug works could lead to better anti-depressant treatments, the scientists believe.

Studies have shown that depressed patients who have resisted all other treatments improve within hours after receiving ketamine.

The drug is not a practical therapy because it has to be administered intravenously to work as an antidepressant and can cause short-term psychotic symptoms.

But scientists today said ketamine could act as a guide to highly promising new treatments for depression.

"It's like a magic drug," said Prof Ronald Duman, a psychiatrist at Yale University in the US. "One dose can work rapidly and last for seven to 10 days."

Most antidepressants, such as Prozac, take weeks or even months to "kick in". In contrast, ketamine's effects are felt within hours.

Ketamine, originally designed as an anaesthetic and tranquilliser, was made a Class C banned recreational drug in 2006.

During the 1990s, it became popular among clubbers who took the drug in pills to experience its "trippy" and hallucinogenic effects.

Although relatively harmless in small doses, ketamine can cause psychological dependency and leave users helpless and vulnerable. It has a notorious reputation as a "date rape" drug. Ketamine can also be dangerous when mixed with alcohol or other drugs.

Ketamine's antidepressant potential has been highlighted in clinical experiments in the US dating back 10 years.

The studies have shown that almost 70 per cent of difficult-to-treat patients respond well to injected ketamine within hours.

Ketamine has also been shown to rapidly prevent suicidal thoughts, a benefit not usually seen until weeks of treatment with traditional anti-depressants.

Prof Duman's team, whose research is reported today in the journal Science, mapped the molecular action of the drug on the brains of rats.