RESUMEN
Interpersonal trust is fundamental for the recovery of trauma survivors and the effectiveness of group psychotherapy. Yet there is limited research on the relationship between interpersonal trust and group psychotherapy. Twenty-one male Vietnam combat veterans with posttraumatic stress disorder (PTSD) (6 in a long-term process group [LTP], 10 in a short-term cognitive processing therapy group [CPT], and 5 treatment-as-usual controls) were evaluated before and after group psychotherapy using the Posttraumatic Stress Disorder Checklist-Military Version (PCL-M) and an in-vivo measure of interpersonal trust, the Iterated Trust Game. Three (14.3%) of the veterans were African American, 9 were Caucasian (42.9%), and 9 were Hispanic (42.9%); they averaged 61.9 years of age (SD = 1.8 years). Change in PCL-M scores differed by group (controls: -1.0 ± 3.7; CPT: -15.5 ± 6.8; LTP: -1.3 ± 12.2; p = .003). CPT group subjects improved more than controls (p < .001) and trended toward more improvement than the LTP group (p = .081). Members of the LTP group, compared to nonprocess group participants, showed greater initial (p = .042), and posttherapy trust (p = .003). Posttreatment, interpersonal trust was significantly higher in the LTP than the CPT group (p < .001). These results suggest that CPT treatment may be better than LTP treatment for improving PTSD symptoms, but LTP therapy may be better than CPT therapy for improving interpersonal trust in veterans with PTSD. They suggest important roles for both group treatments and point to the value of interpersonal trust in successful recovery from PTSD.