Researchers at Baylor College of Medicine (BCM) and the Michael E. DeBakey Veterans Affairs Medical Center have discovered that patients with therapy resistant depression who present with suicidal thoughts respond to a low dose of ketamine (an anesthetic).
The experimental design involved a randomized, double-blind control trial with the control group receiving midazolam. Midazolam is a short-acting anesthetic, generally used to generate drowsiness and decrease anxiety before surgeries. The second group was administered a single 40-minute infusion of ketamine. Researchers report that 53 percent of the ketamine group scored zero on suicide measurements, while about half of the control group scored zero. Researchers report that ketamine has a fast effect that manifests itself one day after infusion and for some patients, the effect persisted for a week or longer. Researchers also report that ketamine was particularly effective with patients who had a higher severity of suicidal thought.
According to Dr. Sanjay Mathew, associate professor the Menninger Department of Psychiatry and Behavioral Sciences at Baylor and a psychiatrist at Debakey VA Medical Center who is senior author of the paper, notes, “Its an interesting finding. We don’t know how specific the ketamine effect is on suicide as opposed to its effect on depression. We know that there were robust effects on depression, and it appears that that the reductions in depression mediated the improvement in suicide. So what’s left unanswered is whether this has a suicide-specific effect or is this driven entirely by the overall improvements in mood.” Mathew goes on further to say, currently there are no FDA approved medications for suicidal thoughts in depressed patients, and no antidepressant has ever been shown to be effective for decreasing suicide in depression. “It’s a huge unmet need in the field.”
Mathew points out, this is the beginning of more research to come on ketamine as a possible therapy for suicidal individuals. Next on the agenda will be a multi-center trial to study ketamine effects on suicidal patients in the emergency room setting. Current research has prompted the pharmaceutical industry to test the use of ketamine further. Mathew and colleagues will partner with a pharmaceutical company to study intranasal ketamine in the emergency room (ER) setting in hopes that it will decrease suicide in the ER setting and decrease the number of hospitalized days.
Others who took part in the study include Dr. Rebecca B. Price of the University of Pittsburgh School of Medicine, Dr. Dan V. Iosifescu, Dr. James W. Murrough, Dr. Laili Soleimani and Dr. Dennis S. Charney of the Icahn School of Medicine at Mount Sinai and Dr. Lee C. Chang, Dr. Rayan K. Al Jurdi, Dr. Syed Z. Iqbal and Alexandra L. Foulkes of Baylor and the DeBakey VA.