Posttraumatic Stress Disorder and Posttraumatic Growth Among Combat-Exposed Vietnam Veterans: Is the Association Quadratic or Moderated By Resilience?

Background:Posttraumatic Stress Disorder (PTSD), a disabling psychological condition that is common among combat veterans (McLeay et al., 2017), is associated with Posttraumatic Growth (PTG), a positive change resulting from re-examining the traumatic event and associated core beliefs (Tedeschi et al., 2007). However, empirical evidence on the nature of the association between PTSD and PTG has been inconclusive (e.g., Linear: Dekel et al., 2012; Curvilinear: Tsai et al., 2015; Heterogeneous: Morgan et al., 2017). Moreover, only a few studies have examined the interaction of resilience in the association between PTSD and PTG (e.g., Ying et al., 2016). This study, therefore, examined the association between PTSD and PTG with polynomial regression and moderated regression with resilience, the ability to adaptive cope with adversity (Wingo et al., 2017), and to bounce back and maintain equilibrium (Windle et al., 2012) being the moderator. This is the first study to investigate concurrently the quadratic and moderated associations between PTSD and PTG in older combat-exposed Vietnam veterans.

Methods: Data were collected from Vietnam theater male veterans (N = 117; M_age = 69.53 years, SD= 3.39) using a cross-sectional design and multiple methods (self-report and interview). Participants were recruited from various local branches of veterans organizations such as Vietnam Veterans of America, Veterans of Foreign Wars, American Legions, and Veterans Outreach Center, as well as from the community in Western New York. Most of them (94%) were non-Hispanic White, 28.2% had a 4-yr college or graduate education, 76.1% were married or cohabiting, and 57.2% had an annual household income between 50,000 to 99,000.

A moderated regression analysis was conducted to test the interaction between PTSD and resilience in predicting PTG, where PTSD was an observed composite of self-report (PCL-5) and interview scores (ADIS-5; Brown & Barlow, 2014). Similarly, polynomial regression tested the hypothesized quadratic effect of PTSD on PTG.

Results: The interaction of resilience with PTSD in predicting PTG was significant (β = 0.19; p < .05), as were the main effects of PTSD (β = 0.49; p < .05) and resilience (β = 0.33; p < .05), after accounting for covariates (e.g., income, social support, physical health). Regarding the shape of the association between PTSD and PTG, the quadratic regression coefficient was not significant, but showed a trend effect (β = -3.003; p = .07), suggesting that PTSD has a negative impact on PTG after a turning point, where the curve starts to drop, forming an inverted U-shape.

Implications: Findings indicate significant role of resilience in the context of PTSD and its direct positive effect on PTG. This has both clinical and empirical relevance with veterans and training implications for active-duty military personnel. Moreover, assessing PTG and resilience alongside PTSD will add to a strength-based therapeutic approach in Social Work. Future research could focus on the trajectory of PTSD, PTG, and resilience using a retrospective longitudinal approach.