Do Benzodiazepines Impair Fear Extinction?

Benzodiazepines are thought to impair behavioral treatment of anxiety in anxious patients, but the evidence has been inconsistent, despite many animal studies clearly demonstrating such an effect. In an elegant group of animal studies, researchers have now examined and clarified this effect.

Rats were trained to fear a context or discrete cue. The fear was then extinguished either in one long session after animals received midazolam or in two sessions (1 hour apart), with midazolam given before the second session. All tests of extinction were performed when rats were drug free. Rats given one long extinction session plus midazolam had impaired extinction 1 day later, but those given interrupted extinction with midazolam showed no such impair…