The effectiveness of acceptance and commitment therapy (ACT) counseling on rumination, internalized shame, and distress tolerance in women affected by marital infidelity.

To determine the effectiveness of acceptance and commitment therapy (ACT) counseling in reducing rumination, reducing internalized shame, and increasing distress tolerance in women affected by marital infidelity

A controlled clinical trial with parallel groups, single-blinded, randomized, on 30 patients.

Convenience sampling will be conducted among women affected by marital infidelity who refer to counseling centers and psychological clinics in Ahvaz city. They will be randomly assigned to intervention and control groups using a randomized block design. This study will be conducted in a single-blind manner and the evaluators and data analysts will be unaware of the grouping of participants (intervention or control).

Inclusion criteria: Gender: Female, Age: 20 to 50 years, Experience of marital infidelity, Referral to counseling centers or psychological clinics in Ahvaz due to mental or emotional problems resulting from marital infidelity, Inclusion criteria: Presence of severe psychiatric disorder, Use of stable psychiatric medications, Presence of acute family crises

Intervention group (ACT): Treatment method: Acceptance and commitment therapy (ACT) with an emphasis on emotional acceptance, commitment to values, and reduction of rumination. Number and duration of sessions: 8 weekly sessions (90 minutes each session) individually or in groups. Content: Mindfulness exercises, self-compassion, and distress tolerance skills. Equipment: Educational handouts, questionnaires, and a quiet counseling environment. Control group: Intervention: Received usual counseling services (without ACT) or a waiting list. Assessment: Pre-test and post-test similar to the ACT group.

Rumination, internalized shame, distress tolerance

The randomization method used in this study is block randomization with a fixed block size of 4. The allocation sequence will be generated using Random Allocation Software and placed in sequentially numbered, sealed, opaque envelopes. After final confirmation of each participant's eligibility, the researcher will open the envelopes in sequential order and assign individuals to either the intervention or control group.

Assessors and data analysts will be unaware of the grouping of participants (intervention or control) to avoid bias in the measurement of outcomes. Participants cannot be blinded to the nature of the intervention (counseling), but they will be informed that they are receiving one of the validated intervention methods. The interventionist (counselor) cannot be blinded to the nature of the ACT treatment, but the intervention protocol will be implemented in a standardized manner to reduce bias. This design is considered a single-blind design.