RESUMEN
BACKGROUND: Combat-related chronic post-traumatic stress disorder (PTSD) is a therapeutically resistant disorder of the fluctuating course. The success of a group psychotherapy is partial. The aim of this paper is to determine baseline characteristics of veterans for whom a group psychotherapy will be the effective psychotherapeutic treatment. SUBJECTS AND METHODS: We performed this prospective cohort study in two geographically distant institutions: Regional Psychotrauma Center at the Psychiatric Clinic Split, and the Daily Hospital of the Psychiatric Hospital "Sveti Ivan" Zagreb, Croatia. We selected a consecutive sample of 86 veterans with combat-related chronic PTSD admitted to the group psychotherapy during 2009-2012. The primary outcome was ≥5% improvement in PTSD symptoms severity measured by Mississippi Scale for Combat-Related PTSD and adjusted for the baseline Mississippi scale score. Predictors were participants' 17 baseline sociodemographic and clinical characteristics and psychological features like personality traits, stress-coping mechanisms, and depression. RESULTS: We identified two patients' segments with significantly higher likelihood for the favorable treatment outcome. The first one were patients with the low score (≤8) on the phobia scale and high score (≥7) on the hysterical personality scale. In this segment 100% of patients experienced a favorable treatment outcome. The second one were the patiens with a higher score (>8) on the phobia scale, the low score (≤12) on the free-floating anxiety scale and the high score ≥8) on the obsession scale. In this segment, 64% experienced the favorable treatment outcome. CONCLUSION: The favorable outcome of the group psychotherapy of PTSD symptoms severity in patients with combat-related chronic PTSD can be predicted before the start of the treatment. The favorable outcome should be expected in patients with the low phobia and pronounced hysteria personality traits, or in patients with higher phobia, but with low free-floating anxiety and low obsession.