The interaction of BDNF Val66Met, PTSD, and child abuse on psychophysiological reactivity and HPA axis function in a sample of Gulf War Veterans

While the BDNF Val66Met polymorphism has been linked to various psychological disorders, limited focus has been on its relationship to posttraumatic stress disorder (PTSD) and early traumas such as child abuse. Therefore, we assessed whether Val66Met was associated with fear potentiated psychophysiological response and HPA axis dysfunction and whether PTSD status or child abuse history moderated these outcomes in a sample of Veterans. 226 and 173 participants engaged in a fear potentiated acoustic startle paradigm and a dexamethasone suppression test (DST) respectively. Fear conditions included no, ambiguous, and high threat conditions. Psychophysiological response measures included electromyogram (EMG), skin conductance response (SCR), and heart rate. The Clinician Administered PTSD Scale (CAPS) and the Trauma History Questionnaire (THQ) were used to assess PTSD status and child abuse history respectively. Met allele carriers exhibited greater SCR magnitudes in the no and ambiguous threat conditions (p