UT Southwestern Medical Center scientists are shedding new light on why the anesthetic¹（麻醉的） drug ketamine produces a fast-acting antidepressant response in patients with treatment-resistant depression. The drug's robust² effect at low doses as a fast-acting antidepressant potentially has use in emergency rooms with high-risk patients.

"Ketamine produces a very sharp increase that immediately relieves depression," said Dr. Lisa Monteggia, associate professor of psychiatry³ at UT Southwestern and senior author of the study published June 15 in Nature.

Typical antidepressant medications – one of the most widely prescribed classes of drugs in the U.S. each year – often take several weeks to relieve symptoms of depression. If they are not successful within 12 weeks, physicians must prescribe a different antidepressant to produce a response.

"Ketamine produces a fast-acting antidepressant effect, and we hope our investigation⁴ provides critical information to treat depression effectively sooner," Dr. Monteggia said.

"We now have a novel pathway to explore that may provide potential for the development of faster-acting and longer-lasting antidepressants," Dr. Monteggia said.

The next step, Dr. Monteggia said, is to investigate further the short- and long-term effects of the changes that occur when the brain cells communicate with each other.