Dorte Christiansen1 and Ask Elklit2

*1Aarhus University, Institute of Psychology, 2National Center for Psychotraumatology, University of Southern Denmark, Denmark* 

#### **1. Introduction**

112 Post Traumatic Stress Disorders in a Global Context

Zigmond, AS., & Snaith, RP. (1983). The hospital anxiety and depression scale. *Acta Psychiatr* 

Research into the psychological sequalae of trauma originally started out by focusing on two sex-specific trauma populations: male war veterans with "soldier's heart", "shellshock", "battle fatigue", or "war neurosis" and female victims of sexual assault or domestic violence with "rape trauma syndrome" or "battered woman syndrome". It was noted how the flashbacks and nightmares reported by rape survivors were similar to the symptoms reported by war veterans, and several researchers and clinicians started pointing out that these trauma specific syndromes might be more similar than different (Ray, 2008; Van der Kolk, 2007). Finally, it was the large number of male Vietnam veterans and the activities of feminist and student organisations, which led to the inclusion of the first PTSD diagnosis into the American DSM-III in 1980 (American Psychiatric Association, 1980). With the introduction of the PTSD diagnosis, the idea that the male war neurosis and the female rape trauma syndrome were ultimately manifestations of the same disorder was widely accepted. As a result, most research on PTSD has been based on the idea that males and females are traumatised in similar ways, and studies on sex differences in PTSD have primarily focused on examining and explaining sex differences in the prevalence and severity of PTSD, whereas studies on sex differences in the manifestation of PTSD are almost completely absent from this otherwise expanding area of research.

Most literature on sex differences in PTSD uses the terms sex and gender interchangeably. Traditionally, however, the term sex refers to the biological distinction between males and females, whereas gender refers to the much more complex cultural understanding of masculine and feminine gender roles as they are viewed in the context of not only sex, but also culture, subculture, age, race, class, and sexual orientation. Even though many studies on PTSD claim to examine gender differences, most studies have in fact studied sex differences and only few have looked into the effect of masculinity or femininity on PTSD. Although this chapter will focus primarily on sex, we acknowledge that gender is likely to affect the development and maintenance of PTSD in males and females as well. The contribution of sex versus gender based explanations for sex differences in PTSD will be discussed throughout the chapter, although the topic merits a more thorough discussion than is possible here.

society, men and women are exposed to different stressors on a day-to-day basis (Barnyard & Graham-Bermann, 1993; Ptacek et al., 1992). This structural theory is likely to influence not only the types of traumatic events males and females are exposed to, but also how they generally respond to such events. Thus, one possible explanation for the sex difference in the prevalence and severity of PTSD is that males and females differ in the types of trauma they experience. A well-conducted meta-analysis by Tolin and Foa (2008) found that across studies, more males than females are exposed to accidents, non-sexual assaults, combat or war, disasters, illness, unspecified injuries, and witnessing the death or injury of others. In contrast, more females experience sexual assault and childhood sexual abuse (CSA). However, it should be kept in mind that these findings are based simply on whether or not the subjects report having been exposed to the different types of PTE's. Males and females may not only be subject to different reporting bias, but may also differ in the number of times they have been exposed to each event, and such differences are unlikely to be identified in this type of meta-analysis. Thus, even though females are less likely overall to be subjected to non-sexual assaults, overall, it is possible that females who are exposed tend to be assaulted repeatedly, such as is often the case in domestic violence. It remains to be seen, whether such differences in multiple exposures to the same type of PTE add to the sex difference in PTSD prevalence. In addition to an increased risk of sexual assault, females also appear to be more exposed to betrayal trauma, in that more females than males report having been exposed to interpersonal trauma, especially assault by a perpetrator close to the

Certain types of trauma (e.g. rape, CSA, combat) have been found to be more toxic (i.e. more likely to lead to PTSD) than others (e.g. accidents, bereavement; Kessler et al., 1995). It is therefore possible that the increased risk of sexual trauma in childhood, adolescence, and adulthood in females may account for differences in PTSD prevalence. However, studies have found that sex differences in PTSD prevalence persist even after trauma type is controlled, indicating that the high prevalence of PTSD in females is not simply a result of increased exposure to sexual trauma (Kessler et al., 1995; Tolin & Foa, 2008). However, even though studies have shown that sex differences in PTSD prevalence exist across trauma types, sexual assault prior to the index trauma is rarely controlled for and may still contribute to the increased PTSD prevalence in females following new traumas. Furthermore, even within the same type of trauma, males and females may differ in the characteristics as well as their interpretation of the event (Tolin & Foa, 2008). For example, a woman who is robbed in an isolated spot may fear that the robber will also rape her and thus have a stronger physiological reaction than a man in the same situation, who may be less likely to interpret the event as anything more than a robbery, although males as well as

females may interpret the event as highly threatening and even fear for their lives.

Interestingly, studies based on military and police samples have generally failed to find an increased risk of PTSD in females compared to males (Lilly et al., 2009). Although male and female military veterans generally differ in the types of events they have been exposed to, it is also possible that the lack of reported sex difference is related to one or more variables on which police and military females differ from female civilians. Furthermore, the metaanalysis by Tolin and Foa, (2008) found that a significant sex difference in PTSD rates has not been established following adult and childhood sexual assault and abuse. This failure to discover significant sex differences in PTSD following sexual assault and abuse may be accounted for by the relatively low number of both-sex studies focusing on these two

victim (Goldberg & Freyd, 2006).
