Feb. 8 (UPI) -- Researchers from Columbia University Medical Center, or CUMC, have discovered that a single dose of ketamine, given one week before a stressful event, has the potential to prevent post-traumatic stress disorder, or PTSD, symptoms.
The study used mice that were given a small intravenous dose of ketamine, a drug used as a general anesthetic or rapid-acting antidepressant, and showed the potential to prevent PTSD symptoms.
Mice were given ketamine while a control group of mice were given a placebo either one month, one week or one hour before they were subjected to a series of small shocks. This resulted in the mice associating the test environment with the shocks, and they were later returned to the same environment and assessed for their fear response or freezing behavior.
The mice that were given ketamine one week before receiving the series of shocks showed reduced freezing when they were returned to the test environment.
"Our findings indicate that the timing of ketamine administration is critical for buffering fear expression," Josephine C. McGowan, a doctoral student in Neurobiology and Behavior at CUMC and first author of the study, said in a press release.
Previous studies have shown that ketamine given before trauma can help reduce stress-related symptoms.
"Ketamine is a powerful drug, and we wouldn't advocate widespread use for preventing or reducing PTSD symptoms," Christine A. Denny, Ph.D., assistant professor of clinical neurobiology in the Department of Psychiatry at CUMC and lead author of the study, said in a press release. "But if our results in mice translate to humans, giving a single dose of ketamine in a vaccine-like fashion could have great benefit for people who are highly likely to experience significant stressors, such as members of the military or aid workers going into conflict zones."
Researchers found that ketamine given after a stressful event did not affect the fear response in mice, but that giving ketamine one hour after a second shock decreased the fear response.
The study was published in Neuropsychopharmacology.