Using a multi-method assessment strategy, we examined whether a possible common cognitive factor in symptoms of PTSD and depression – hopelessness – was cross-sectionally and prospectively related to symptoms of PTSD. An initial regression analysis indicated that both self-reported and interviewer-rated hopelessness were concurrently related to self-reported PTSD symptoms at 2 weeks post-trauma, accounting for 18.5% of variance. This relationship virtually disappeared when the effects of concurrent depression were accounted for, suggesting that the relationship was due to shared variance with depression. Regression analysis also indicated that self-reported and interviewer-rated hopelessness assessed at 2 weeks post-trauma accounted for 14.4% of variance in self-reported PTSD symptoms assessed at 3 months post-trauma. As with the 2-week post-trauma findings, the prospective relationship between hopelessness and PTSD symptoms virtually disappeared when the effects of concurrent depression were accounted for; again, it appears that relationships between hopelessness and PTSD symptoms are due to shared variance between PTSD symptoms and depression. Overall, these findings suggest that hopelessness has a shared relationship with symptoms of both PTSD and depression.
Kazdin and colleagues (Kazdin, Kraemer, Kessler, Kupfer, & Offord, 1997
; Kraemer, Kazdin, Offord, Kessler, Jensen, & Kupfer, 1997
) provide several ideas for understanding and defining whether a given correlate is a risk factor for an outcome of interest. In part, they propose the following: (i) when 2 factors are associated with one another at the same time point, these factors may be characterized as correlates and (ii) when 2 factors are associated with one another, and one factor precedes the other, the preceding factor may be characterized as a special type of correlate, that is, a risk factor. Risk factors are further described according to their manipulability and causal status. For example, a risk factor that is potentially malleable but that has not yet been shown to alter outcomes when manipulated is termed a variable risk factor. Using this typology, the cross-sectional findings of this study suggest that hopelessness is a correlate of PTSD symptoms, and the prospective findings suggest that hopelessness is a variable risk factor for PTSD symptoms. The findings do not address whether hopelessness has a causal role in the development of PTSD symptoms.
While this study found consistent relationships between hopelessness and self-reported PTSD symptoms, analyses also suggested that neither self-reported nor interviewer-rated hopelessness is related to interviewer-rated PTSD symptoms. This discrepancy may be due to several factors. First, given the relatively low correlations between self-reported and interviewer-rated measures of PTSD symptoms found in this sample (ranging from 0.13 to 0.39), the PSS-SR and CAPS may be assessing somewhat different aspects of the same phenomenon. The 2 measures also differ in terms of whose perceptions are recorded. Moreover, both measures are open to unique biases that may have affected the findings, including halo effects for the CAPS (Groth-Marnat, 2003
; Schnurr, Friedman, & Bernardy, 2002
) and limited opportunity to clarify questions or responses for the PSS-SR. Nonetheless, given that both self-reported and interviewer-assessed hopelessness were related to self-reported PTSD symptoms, the discrepancy in findings when utilizing different methods of symptom assessment deserves further investigation.
Overall, our findings have potential clinical and research implications. First, assessing for hopelessness in the initial post-trauma period may be helpful in identifying persons who are at risk of developing co-morbid PTSD and depression symptoms. Second, for both conceptual and clinical reasons, it may be important to determine whether hopelessness is a causal risk factor for the development of PTSD symptoms, perhaps by addressing hopelessness cognitions as part of post-trauma psychotherapeutic intervention and then examining whether changes in hopelessness alter levels of PTSD symptoms. It may also be fruitful to compare relationships between hopelessness and PTSD symptoms among various trauma samples, as various trauma types have been associated with different levels of risk for the development of PTSD (Breslau et al. 1998
; Kessler et al., 1995
). This differential level of risk may lead to differential importance of specific variable risk factors such as hopelessness. Due to power considerations, we did not conduct such analyses in the current sample.
While these results and their potential implications are intriguing, they must be considered in light of some limitations. First, this study was conducted with an entirely female sample. Accordingly, these findings may not generalize to men, who generally have lower risk for both PTSD and depression (Breslau et al., 1998
; Brewin, Andrews, & Valentine, 2000
; Kessler et al., 1995
; Kessler et al., 1996
; Nolen-Hoeksema, 1990
). Second, the divergence in results when using self-report vs interview measures of PTSD symptoms deserves further scrutiny (see Griffin, Uhlmansiek, Resick, & Mechanic, 2004
, for a recent empirical comparison of self-report and interview PTSD measures).
In summary, our results suggest that hopelessness has a shared relationship with self-reported PTSD and depression symptoms. These findings have several potential implications, both for a better understanding of the nature and development of PTSD symptoms and for early identification of persons at risk. Nonetheless, consistent with the exploratory nature of this study, additional research is needed to replicate these findings among men and people with other types of trauma, to further examine relationships between hopelessness and self-reported vs interviewer-assessed PTSD symptoms, and to determine whether hopelessness is a causal risk factor for PTSD.