Brief post-stressor treatment with pregabalin in an animal model for PTSD: Short-term anxiolytic effects without long-term anxiogenic effect

Background: The short- and long-term behavioral effects of a brief course of pregabalin, an antiepileptic structural analogue of α-aminobyturic acid with analgesic and anxiolytic effects, were assessed in an animal model of post-traumatic stress disorder (PTSD). Method: Two-hundred thirty-three adult male Sprague-Dawley rats were employed. Behavioral responses to traumatic stress exposure (predator urine scent) were assessed immediately after (1 h) and 30 days after treatment with saline or pregabalin (at doses of 30, 100 and 300 mg/kg) in terms of behavior in the elevated plus maze (EPM) and the acoustic startle response (ASR) paradigms. At day 31 the freezing response to a trauma cue (clean cat litter) was assessed. The same treatment regimen initiated at day 7 was assessed at day 30 and in response to the trauma cue on day 31 in a separate experiment. Results: In the short term, doses of 100 mg/kg and 300 mg/kg of pregabalin effectively attenuated anxiety-like behaviors. In the longer-term, pregabalin did not attenuate the onset of PTSD-like behaviors or the prevalence rates of severe cue-responses, for either the immediate or the delayed treatment regimens. Conclusion: Pregabalin may present an alternative compound for acute anxiolytic treatment after exposure to trauma, but has no long-term protective/preventive effects.