From VOA Learning English, this is the Health Report.

Ketamine is a drug that puts people and animals into a deep sleep. Doctors inject it into patients so they can be operated on. However, Ketamine may prove useful as a mental health too.

A new study shows that the anesthesia drug may help people who suffer from depression. Researchers in Britain studied 28 patients suffering from severe depression. Most of the patients experienced a major ease in the effects of depression after receiving ketamine injections.

Rupert McShane led the study. He says eight of the 28 patients injected got good results. And, Dr. McShane reported that three of those eight said they felt better just hours after getting one injection of ketamine. The drug’s apparent effects lasted one to six months.

Researchers in the United States have carried out six larger studies on ketamine and depression. They found the drug quickly eased the effects of a kind of depression that is usually resistant to treatment.

Carlos Zarate is a researcher with the U.S. National Institute of Mental Health. He says there are 30 different kinds of antidepressant drugs on the market. But, he says, a single kind will not ease all the effects of the disorder. As a result, Mr. Zarate says, most patients with depression are treated with more than one antidepressant.

The researcher says ketamine directly targets a brain chemical linked to depression. He says traditional antidepressants target that chemical only indirectly. The British study of ketamine was published in the Journal of Psychopharmacology.