Abstract
Parental Posttraumatic Stress Disorder (PTSD), particularly maternal PTSD, confers risk for stress-related psychopathology among offspring. Altered hypothalamic-pituitary-adrenal (HPA) axis functioning is one mechanism proposed to explain transmission of this intergenerational risk. Investigation of this mechanism has been largely limited to general stress response (e.g., diurnal cortisol), rather than reactivity in response to an acute stressor. We examined cortisol reactivity in response to a laboratory stressor among offspring of mothers with a lifetime diagnosis of PTSD (n=36) and age- and gender- matched control offspring of mothers without PTSD (n=36). Youth (67% girls; mean age=11.4, SD=2.6) participated in a developmentally sensitive laboratory stressor and had salivary cortisol assessed five times (one pre-stress, one immediate post-stress, and three recovery measures, spaced 15min apart). Results were consistent with the hypothesis that offspring of mothers with PTSD would exhibit a dysregulated, blunted cortisol reactivity profile, and control offspring would display the expected adaptive peak in cortisol response to challenge profile. Findings were maintained after controlling for youth traumatic event history, physical anxiety symptoms, and depression, as well as maternal depression. This finding contributes to the existing literature indicating that attenuated HPA axis functioning, inclusive of hyposecretion of cortisol in response to acute stress, is robust among youth of mothers with PTSD. Future research is warranted in elucidating cortisol reactivity as a link between maternal PTSD and stress-related psychopathology vulnerability among offspring.