Background: At the midpoint of a large clinical trial taking place in a practice-based research network (PBRN), we asked leaders of the enrolled practices about the impact of participating in a PBRN study.Methods: Using semistructured interviews, the lead study nurse and physician from each site were queried about the impact of study participation on issues related to the study topic of postpartum depression (PPD) as well as any other impacts on the practice not directly related to PPD. From the results, initial themes were identified by 3 of the investigators (BPY, SB, MK) and confirmed by all the authors. Interviewee responses were grouped by theme.Results: Forty-eight study leaders from 28 solo, moderately sized group and residency practices were interviewed during a period of 60 days. Practices were located in 20 different states, and 54% were in rural communities. Six major themes emerged. Study participation led to: (1) the recognition of the need for systematic approaches; (2) more effective teamwork and communication within the practice; (3) adaptation and extension of the PPD study tools and a systematic approach to the care of other chronic conditions; (4) increased professional self-worth and community recognition; (5) opportunity and support for staff members to "stretch" into new roles; and (6)