A single dose of ketamine, given one week before a stressful event, can buffer against a heightened fear response, according to a study published in the journal Neuropsychopharmacology .
In the study, mice were given a small dose of intravenous ketamine or placebo one month, one week, or one hour before experiencing a series of small shocks. The mice were later returned to the same environment and assessed for their freezing behaviour as a measure of fear response. Only those given ketamine one week before the stressor exhibited reduced freezing when they were returned to the test environment. Giving ketamine immediately after the stressor did not affect fear response. However, administration one hour after a second shock decreased fear expression, suggesting that there may be another potential window after the initial trauma when the drug may be effective.
“Ketamine is a powerful drug, and we wouldn’t advocate widespread use for preventing or reducing PTSD symptoms. 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,” said study leader Christine Denny, assistant professor of clinical neurobiology in psychiatry at Columbia University.