Wonder drug: Ketamine can get you out of deep depression within minutes of administration

WASHINGTON DC. [USA]: A recent study has shown that ketamine, unlike most antidepressants, can get a person out of deep depression a few minutes after administration.

The researchers, led by Mark Rasenick, University of Illinois at the College of Medicine in Chicago, describe the molecular mechanisms behind the ability of ketamine to crush depression and keep it at bay.

"Two-thirds of clinical trial participants who did not respond to traditional antidepressants experienced rapid and lasting resolution of their depressive symptoms after receiving intravenous ketamine," Rasenick said.

The effects of ketamine usually lasted about a week – much longer than expected with the six-hour half-life of ketamine in the body.

Rasenick and his colleagues used a cell model system to study how ketamine acted.

In his current research, Rasenick and his colleagues had an experiment with ketamine and noticed that G proteins were leaving rafts much more quickly. G proteins began to migrate off lipid rafts in 15 minutes. And the lasting effects of ketamine may be due to the fact that G proteins were very slow to return to lipid rafts, Rasenick explained.

The discovery contradicts the long-held idea that ketamine works only by blocking a cellular receptor called the NMDA receptor, which is on the surface of nerve cells and helps transmit signals.

In fact, when the researchers eliminated the NMDA receptor, ketamine still had the same effect on the cells – by rapidly moving the G proteins out of the lipid rafts onto the cell membrane.

"When G proteins are released from lipid rafts, this allows for better communication between brain cells, which is known to help relieve some of the symptoms of depression," said Rasenick.

"Whether they are withdrawn by traditional antidepressants or ketamine, it does not matter, even if with ketamine, G proteins are very slow to return to lipid rafts, which would explain the long-term effects of drugs on depressive symptoms. "

"This further illustrates that the movement of G proteins from lipid rafts is a true biomarker of antidepressant efficacy, regardless of how they work," Rasenick explained.

"It confirms that our cell model is a useful tool to show the effect of potential new antidepressant drug candidates on the movement of G proteins and the possible effectiveness of these drugs in the treatment of depression."

The study appears in the journal Molecular Psychiatry.