Yohimbine use in a natural setting: effects on posttraumatic stress disorder.

BACKGROUND: Numerous laboratory-based studies have shown that chronic posttraumatic stress disorder (PTSD) is associated with alterations in catecholamines. In a recent neuroendocrine challenge study, IV yohimbine caused exaggerated subjective, behavioral, cardiovascular and catecholamine responses among combat veterans with PTSD compared to healthy controls. Yohimbine is an alpha-2-adrenergic receptor antagonist that activates noradrenergic neurons. METHODS: This report describes the experience of 4 individuals with PTSD who took over-the-counter oral yohimbine that they had purchased from a health food store or pharmacy. RESULTS: All 4 subjects experienced a marked exacerbation of anxiety/panic and PTSD-specific symptoms immediately after ingesting yohimbine in a natural setting. CONCLUSIONS: The response in these individuals closely resembled the response observed after IV yohimbine in combat veterans with PTSD. The present cases occurred in a natural setting and thus complement laboratory-based findings. The authors caution against the recreational or medical use of yohimbine in individuals who have PTSD.