Washington: Yale scientists have discovered a new drug that shows anti-depressant effects in hours, rather than weeks or months.
Yale scientists found that, in rats, ketamine not only quickly improves depression-like behaviours but also actually restores connections between brain cells damaged by chronic stress.
"It’s like a magic drug—one dose can work rapidly and last for seven to 10 days," said Ronald Duman.
Ketamine is traditionally used as an anaesthetic in children, but experts found that in low doses, it can treat depression too.
However, its clinical use has been limited because it has to be delivered intravenously under medical supervision and in some cases can cause short-term psychotic symptoms.
To find out the effect of the drug, the team conducted the study in rats.
"The pathway is the story. Understanding the mechanism underlying the antidepressant effect of ketamine will allow us to attack the problem at a variety of possible sites within that pathway," George Aghajanian said.
The team identified a critical point in the pathway, the enzyme mTOR, which controls protein synthesis required for new synaptic connections.
The authors note that ketamine also has been tested as a means to rapidly treat people with suicidal thoughts, a benefit usually not seen until weeks of treatment with traditional antidepressants.
The findings are described in the August 20 issue of the journal Science.