Divorce is a major source of trauma, especially among women in societies with clearly defined traditional gender roles. As such, depression is prevalent among divorced women. The use of group-based trauma-focused cognitive behavioral therapy for recently divorced women in Tehran has been found to be effective in alleviating depressive symptoms. This case study examines how a randomized controlled trial research design can be used to assess treatment effectiveness. It also provides insights into the practicalities of conducting group psychotherapy from both research and clinical perspectives.