Recent studies suggest that ketamine, a widely used anesthetic agent, could offer a wholly new approach to treating severe depression — producing an antidepressant response in hours rather than weeks. Two reviews of recent evidence on ketamine and related drugs for treating depression appear in the Harvard Review of Psychiatry, published by Wolters Kluwer.
Ketamine and related drugs may represent a “paradigm shift” in the treatment of major depressive disorder (MDD) and bipolar depression — especially in patients who do not respond to other treatments, according to a review by Carlos A. Zarate, Jr, MD and colleagues at the National Institute of Mental Health. A second article explores evidence on the mechanisms behind ketamine’s rapid antidepressant effects.
Ketamine was significantly more effective than a commonly used sedative in reducing suicidal thoughts in depressed patients, according to researchers at Columbia University Medical Center (CUMC). They also found that ketamine’s anti-suicidal effects occurred within hours after its administration.
The findings were published online last week in the American Journal of Psychiatry.
According to the Centers for Disease Control and Prevention, suicide rates in the U.S. increased by 26.5 percent between 1999 and 2015.
“There is a critical window in which depressed patients who are suicidal need rapid relief to prevent self-harm,” said Michael Grunebaum, MD, a research psychiatrist at CUMC, who led the study. “Currently available antidepressants can be effective in reducing suicidal thoughts in patients with depression, but they can take weeks to have an effect. Suicidal, depressed patients need treatments that are rapidly effective in reducing suicidal thoughts when they are at highest risk. Currently, there is no such treatment for rapid relief of suicidal thoughts in depressed patients.”
When they work, antidepressant medications may take weeks or months to alleviate symptoms of depression. Progress in developing new and more effective antidepressant treatments has been limited, though a new study published in Biological Psychiatry offers new insights into how antidepressants work.
Using a mouse model of depression, researchers found that a therapeutic response to antidepressant medication may stem from changes in gene expression that induce resilience and reverse vulnerability to exhibiting depression-like responses to stress. The study, led by Dr. Eric Nestler of the Icahn School of Medicine at Mount Sinai in New York, teases apart the mechanisms of two different antidepressant drugs- the conventional tricyclic antidepressant imipramine and fast-acting ketamine.