Rooyesh-e- Ravanshenasi Journal(RRJ)

This study aimed to determine the effectiveness of group schema therapy on the sense of agency, adherence to health-promoting behaviors, and binge eating severity in women with bulimia nervosa. This study employed a quasi-experimental design with a pretest–posttest control group and a two-month follow-up. The statistical population consisted of women aged 30–50 years diagnosed with bulimia nervosa who attended treatment centers, Overeaters Anonymous, sports clubs, and psychological clinics in Isfahan, Iran, during 2024–2025. 40  participants were selected through purposive sampling and randomly assigned to the experimental or control group. Following sample attrition, data from 32 participants (16 in each group) were analyzed. Data were collected using the Sense of Agency Rating Scale (SOARS; Polito et al., 2013), the Health-Promoting Lifestyle Profile II (HPLP-II; Walker et al., 1997), and the Binge Eating Scale (BES; Gormally et al., 1982). The experimental group received ten weekly 120-minute sessions of group schema therapy. Data were analyzed using repeated-measures analysis of variance. The Findings showed that schema therapy significantly increased the sense of agency and adherence to health-promoting behaviors, while significantly reducing binge-eating severity at posttest (P<0.001). Moreover, no significant differences were observed between the posttest and follow-up assessments (P>0.05), indicating that treatment effects remained stable over time. Overall, group schema therapy appears to be an effective intervention for improving the sense of agency, promoting health-promoting behaviors, and reducing binge eating severity in women with bulimia nervosa.