Suicidal Thoughts Can Be Reduced Through Low-Dose, Intravenous Ketamine

Suicidal thoughts can be reduced with repeated intravenous treatment through low-dose ketamine. This is an anesthetic drug that is usually not employed as the primary treatment, as it seems to have hallucinogenic properties.

The study was conducted by a team of Massachusetts General Hospital (MGH) researchers on a small group of patients who showed "treatment-resistant depression."

"Our finding that low doses of ketamine, when added on to current antidepressant medications, quickly decreased suicidal thinking in depressed patients is critically important because we don't have many safe, effective, and easily available treatments for these patients," said Dawn Ionescu of MGH and lead author of the study. "While several previous studies have shown that ketamine quickly decreases symptoms of depression in patients with treatment-resistant depression, many of them excluded patients with current suicidal thinking."

Medications such as lithium and clozapine, which are used to treat suicidal thoughts, usually tend to have serious side effects. They need to be carefully checked and the blood levels need to be monitored, which makes them expensive. Electroconvulsive therapy has been found to be effective, but might lead to memory loss.

Patients experiencing moderate to severe depression, confessing suicidal thoughts for three months or longer were examined. After determining that they were undergoing antidepressant treatment, the patients were administered ketamine twice every week for three weeks.

Even though just 12 of the 14 participants finished the complete regimen, most of them were seen to experience a decrease in suicidal thinking. Seven of them had a complete remission by the end of the treatment. The doses were administered without any serious side-effects.

Ketamine shows promise, although more research is needed.

"We only studied intravenous ketamine, but this result opens the possibility for studying oral and intranasal doses, which may ease administration for patients in suicidal crises," said Ionescu. "Looking towards the future, studies that aim to understand the mechanism by which ketamine and its metabolites work for people with suicidal thinking and depression may help us discover areas of the brain to target with new, even better therapeutic drugs."

The findings were published on May 10, 2016, online issue of The Journal of Clinical Psychiatry.