Maternal, not paternal, PTSD is related to increased risk for PTSD in offspring of Holocaust survivors

Abstract

Background

A significant association between parental PTSD and the occurrence of PTSD in offspring has been noted, consistent with the idea that risk for the development of PTSD is transmitted from parent to child. Two recent reports linking maternal PTSD and low offspring cortisol prompted us to examine the relative contributions of maternal vs. paternal PTSD in the prediction of PTSD and other psychiatric diagnoses in offspring.

Methods

One hundred seventeen men and 167 women, recruited from the community, were evaluated using a comprehensive psychiatric battery designed to identify traumatic life experiences and lifetime psychiatric diagnoses. 211 of these subjects were the adult offspring of Holocaust survivors and 73 were demographically comparable Jewish controls. Participants were further subdivided based on whether their mother, father, neither, or both parents met diagnostic criteria for lifetime PTSD.

Results

A higher prevalence of lifetime PTSD, mood, anxiety disorders, and to a lesser extent, substance abuse disorders, was observed in offspring of Holocaust survivors than controls. The presence of maternal PTSD was specifically associated with PTSD in adult offspring of Holocaust survivors. However, other psychiatric diagnoses did not show specific effects associated with maternal PTSD.

Conclusion

The tendency for maternal PTSD to make a greater contribution than paternal PTSD to PTSD risk suggests that classic genetic mechanisms are not the sole model of transmission, and paves way for the speculation that epigenetic factors may be involved. In contrast, PTSD in any parent contributes to risk for depression, and parental traumatization is associated with increased anxiety disorders in offspring.

Introduction

Trauma survivors who develop posttraumatic stress disorder (PTSD) have greater rates of familial psychopathology compared to similarly-exposed persons who do not develop this disorder (Davidson et al., 1985, Davidson et al., 1989, Davidson et al., 1998, Dijanic Plasc et al., 2007, Reich et al., 1996, Dierker and Merikangas, 2001). Parental PTSD, in particular, has been demonstrated to be associated with PTSD and related psychopathology in offspring (Rosenheck, 1986, Solomon et al., 1988, Yehuda et al., 1998b, Yehuda et al., 1998c). We previously reported that there was a specific association between parental PTSD and the occurrence of PTSD in offspring when the relative contributions of parental exposure, parental PTSD, and the offspring’s own history of trauma to the development of PTSD, depressive, and anxiety disorders in the offspring were evaluated (Yehuda et al., 2001a). Additionally, parental trauma exposure, more than parental PTSD, was found to be significantly associated with offspring lifetime depressive disorder (Yehuda et al., 2001b).

The potential utility of identifying parental PTSD as a risk factor for PTSD in offspring of Holocaust survivors is that they represent a sample in which the biological and psychological correlates of risk for PTSD can be further examined. In pursuing this goal, we demonstrated that, though not having their own lifetime PTSD, Holocaust offspring with parental PTSD, compared to those without, displayed low urinary (Yehuda et al., 2000, Yehuda et al., 2001b) and plasma (Yehuda et al., 2007b) cortisol levels; and increased glucocorticoid responsiveness as measured by plasma cortisol levels in response to low dose dexamethasone administration (Yehuda et al., 2007a); the former has been linked with increased risk for PTSD in other populations (Anisman et al., 2001, Delahanty et al., 2003, Resnick et al., 1995, Yehuda et al., 1998a).

The possibility that low cortisol in offspring was a transmitted risk factor was further supported by observations of lower salivary cortisol levels in year old infants born to mothers with PTSD compared to infants born to mothers without PTSD, following their direct exposure to the collapse of the World Trade Center on 9/11 during pregnancy (Yehuda et al., 2005). Although the contribution of paternal PTSD to cortisol levels in infant offspring was not examined, there was a significant effect of trimester (i.e., the effect was most present in the third trimester), consistent with in utero contributions to low cortisol in offspring. Alternatively, the trimester effect might reflect the proximity of the birth to the trauma exposure, affecting maternal behavior. Both possibilities are consistent with epigenetic mechanisms for low cortisol in offspring, which may depend on the gender of the traumatized parent.

In view of these findings, a subsequent study of plasma cortisol release at 30 min intervals over the diurnal cycle in Holocaust offspring with no lifetime PTSD examined effects of maternal vs. paternal PTSD and found low plasma cortisol to be associated with maternal PTSD, even after controlling for the contribution of paternal PTSD (Yehuda et al., 2007b). Thus, it was of interest to extend our previous observations about the impact of parental PTSD on offspring PTSD, depression, and anxiety, distinguishing among maternal PTSD, paternal PTSD, or both parents having PTSD. This was accomplished by doubling the original sample size of Holocaust offspring and comparable controls. The increased sample size also afforded the opportunity to report findings on less prevalent conditions: eating disorders, substance abuse, and adjustment disorders. We hypothesized that the previously observed association between parental PTSD and PTSD in offspring would reflect the effect of maternal PTSD. In the prediction of depression (Yehuda et al., 2001a), anxiety and other disorders, we hypothesized that we would not observe a relationship with parental PTSD because an epigenetic model for the transmission of PTSD risk would not generalize to transmission from PTSD to other psychiatric disorders. In that we previously observed an association between parental trauma exposure and depression, we hypothesized that parental trauma might be associated with other psychiatric disorders. Since children are potentially affected by both parents, it was necessary to adjust for the possible impact of PTSD in the other parent when evaluating the effect of either maternal or paternal PTSD and their interaction. Finally, we examined the interaction of the gender of the offspring with parental PTSD gender, since such an interaction would distinguish between a purely genetic model and one involving epigenetics. Accordingly, we hypothesized that such interactions would only be present for PTSD, but not for the other diagnoses.