Who gets better and why? Predicting Outcome Trajectories in STRONG STAR Trials


Aug 18, 2010

The military culture requires, builds, and nurtures cohesive bonds among its members. Cohesion, coupled with good leadership, is critical to successful military efforts, and these factors help service members heal and recover from the stress and trauma of combat. However, no matter how effective, the quality of leadership and group cohesion can vary across deployment cycles, and unique factors in each person’s life can still have a strong effect on individual coping styles and stress responses.

Individual service members adapt differently to combat and operational stress and trauma by virtue of a complex web of biological, social, and service-related risk and resilience factors. Over time, deployed service members follow multiple courses of adjustment. Most are impacted by what they see and do but still recover fully; some grow and become stronger; some have chronic postdeployment mental health problems; and still others experience delayed or maladjustment. Likewise, service members have diverse care needs, and each will respond differently to treatment interventions for mental health problems related to combat and operational stress.

The various causes of these different “trajectories of response” are unknown, leaving commanders and decision-makers with a lack of useful information about how to prevent problems in those most at risk for posttraumatic stress disorder and other mental health problems across the deployment cycle and beyond. It also hampers the efforts of mental health professionals who, ideally, would want to tailor treatment interventions to achieve the best possible outcome for service members.

Identification of response trajectories could propel PTSD research

As the director of the STRONG STAR Assessment Core, Brett Litz, PhD, with the Massachusetts Veterans Epidemiological Research and Information Center, VA Boston Health Care System, and professor at Boston University School of Medicine, has designed a study utilizing the comprehensive dataset from all STRONG STAR clinical trials to perform a variety of analyses with three key aims. One is to identify risk and resilience variables that predict the trajectory, or path, service members follow over time as they adapt to war-zone trauma. The second objective is to examine variables that influence the outcome of treatment interventions or that reveal subgroups of individuals who might be adversely impacted or uniquely changed by various intervention strategies. The third is to conduct a meta-analysis of all the treatment trials to examine how well treatments that have primarily been developed and tested on civilians and veterans with very chronic problems are able to help service members.

Researchers hypothesize that they will see four trajectories of response to combat exposure and operational trauma, as well as to treatment for PTSD:

  • a recovery/positive outcome course, characterized by an initial worsening of symptoms as the individual focuses on the trauma, followed by steady improvement over time;
  • a resilience course, characterized by relatively low symptoms and impairment over time;
  • a relapse course, characterized by apparent treatment gains lost at follow-up intervals; and
  • a chronic worsening course, in which symptoms worsen and then remain high over time.

Dr. Litz and his research team will collapse information across the entire STRONG STAR dataset to evaluate the prevalence of these trajectories of response, as well as the particular biological, psychological, social, and service-related risk and resilience variables that correspond with each trajectory and appear to influence treatment outcomes. For example, individual vulnerabilities, environmental demands of the job, personal appraisals, socio-cultural resources, and certain predisposing behavioral and biological response capacities, including personal coping style, might all be factors in whether someone develops PTSD following trauma, how severe the symptoms are, what outcome path they follow in response to treatment, or even what type of treatment is most or least beneficial for them.

Expected outcomes

As STRONG STAR investigators perform their analyses, they expect to find causal models, or sets of variables, that can be used to predict individuals’ responses to trauma and combat stress and various PTSD treatments. This will provide useful information to support evidence-based decisions about primary and secondary prevention strategies for chronic deployment-related mental health problems, especially PTSD, and to help generate more tailored treatment strategies for maximum impact.