Does Group Size Matter? Group Size and Symptom Reduction Among Incarcerated Women Receiving Psychotherapy Following Sexual Violence Victimization.

is an eight-week therapy group for incarcerated women who have experienced sexual violence victimization. SHARE requires each member to complete an imaginal exposure and to listen when others share their experiences of victimization. While trauma-focused group interventions including SHARE are associated with reductions in internalizing symptoms, little work has examined how group characteristics predict symptom decreases. The purpose of this study was to examine whether group size was associated with symptom changes pre- to post-treatment. Participants (=140 across 29 groups) completed self-report measures of posttraumatic stress symptoms before and after completing SHARE. Multilevel modeling revealed the majority of the variance in post-treatment symptoms was attributed to individual factors rather than group factors. Symptom change was comparable for groups of two to eight women; declines in symptom improvement were observed at a group size of ten participants.