Psychological theories have been developed to explain why certain trauma survivors go to develop PTSD and others not. These theories try to capture what happens at the level of the trauma survivor's personal experiences, in terms of thoughts , memory, emotions, behaviours and underlying processes of which the person is unaware.

Objective: To determine whether group therapy improves symptoms of posttraumatic stress disorder (PTSD), this randomized clinical trial compared efficacy of group cognitive processing therapy cognitive only version; CPT-C) with group present-centered therapy (PCT) for active duty military personnel. Method: Patients attended 90-min groups twice weekly for 6 weeks at Fort Hood, Texas. Independent assessments were administered at baseline, weekly before sessions, and 2 weeks, 6 months, and 12 months posttreatment. A total of 108 service members (100 men, 8 women) were randomized.

Importance Posttraumatic stress disorder (PTSD) is a disabling psychiatric disorder common among military personnel and veterans. First-line psychotherapies most often recommended for PTSD consist mainly of “trauma-focused” psychotherapies that involve focusing on details of the trauma or associated cognitive and emotional effects.
Objective To examine the effectiveness of psychotherapies for PTSD in military and veteran populations.

Importance The long-term course of readjustment problems in military personnel has not been evaluated in a nationally representative sample. The National Vietnam Veterans Longitudinal Study (NVVLS) is a congressionally mandated assessment of Vietnam veterans who underwent previous assessment in the National Vietnam Veterans Readjustment Study (NVVRS).
Objective To determine the prevalence, course, and comorbidities of war-zone posttraumatic stress disorder (PTSD) across a 25-year interval.