The purpose of this study was the effectiveness of couple therapy based on acceptance and commitment on love schemas and emotional schemas in couples with extramarital relationships with a two-month follow-up period. In this research, a single case semi-experimental design of multiple baseline type was used. The statistical population of this research included all couples with experience of extramarital relations who referred to the family courts and prevention unit of Dezful city welfare department in 2021-22. After the diagnostic interview and specifying the couples who met the entry criteria, 4 couples (8 persons) were selected based on purposive sampling. The protocol of the couples therapy method was implemented in the form of three baseline stages and 8 90-minute sessions and a two-month follow-up. The participants responded to Yarmohammadi Vasil et al.'s Love Schema Questionnaire (2019) and Leahy Emotional Schema Scale (LES). The data were analyzed by visual drawing method, stable change index and recovery percentage formula. The results showed that couple therapy based on acceptance and commitment increased adaptive emotional schemas and decreased maladaptive emotional schemas of couples with extramarital relationships (p<0.05). Couple therapy based on acceptance and commitment has a significant effect on secure love schema, unstable love schema, clingy love schema, avoidant love schema, and non-serious love schema (p<0.05) and its results continued until the follow-up stage. Therefore, couple therapy based on acceptance and commitment as a stable intervention to increase love schemas and emotional schemas can be used in health and treatment centers in couples with extramarital relationships.
