While such theorizing and research have impacted productively on our understanding of the development of the symptoms of PTSD, there is little information on whether cognitive factors that influence PTSD may also simultaneously impact the development of co-morbid conditions. Moreover, it is unclear whether such cognitive factors uniquely influence the development of PTSD, or whether they may non-specifically affect the development of PTSD as well as other types of symptoms.
Of particular interest may be whether cognitions implicated in the development of PTSD may also impact the development of depression and vice versa. Indeed, depression co-occurs up to 50% with PTSD (Kessler, Sonnega, Bromet, Hughes, &. Nelson, 1995. see also Kessler et al., 1996) and epidemiological data suggest that they may share common risk factors (Breslau, Davis, Peterson, &. Schultz, 2000). Among possible common risk factors are cognitions regarding oneself, others and the future.
Within this broad set of cognitions, hopelessness beliefs may have particular relevance for the development of symptoms of both PTSD and depression. The hopelessness theory of depression (Abramson, Metalsky, &. Alloy, 1999) posits a chain of factors that may culminate in psychological distress. Of relevance to the development of symptoms of both PTSD and depression, the theory suggests that, following a negative event, several factors contribute to the development of hopelessness: identifying the event as important, attributing the cause of the event to stable and global factors, believing that the event will have negative consequences for one’s life, and believing that the event suggests something negative about oneself. Such hopelessness then culminates in psychological distress. Since the introduction of the hopelessness theory, research has been steadily accumulating that supports its tenets for a hypothesized subtype of unipolar depression, termed ‘‘hopelessness depression’’.