The Effectiveness of Acceptance and Commitment Therapy on Mood Status in Women with Postpartum Depression

Objective: The present study aimed to investigate the effectiveness of acceptance and commitment therapy (ACT) on mood status in women with postpartum depression. Methods and Materials: This applied quasi-experimental study was conducted using a pretest-posttest design with a control group among women with postpartum depression who referred to psychological clinics in Tehran during 2023–2024. From a population of 80 women, 40 participants who met the inclusion criteria were selected through purposive sampling and randomly assigned into experimental and control groups (20 participants in each group). Data were collected using the Beck Depression Inventory and the Profile of Mood States (POMS) questionnaire. The experimental group received eight 120-minute sessions of acceptance and commitment therapy based on Hayes’ protocol, while the control group received no intervention. Data analysis was performed using descriptive statistics, Kolmogorov–Smirnov test, univariate analysis of covariance (ANCOVA), and multivariate analysis of covariance (MANCOVA) in SPSS version 23. Findings: The results demonstrated a significant reduction in mood status scores in the experimental group following the intervention compared with the control group. ANCOVA results indicated that the effect of group membership on overall mood status was statistically significant (F = 6095.615, p < 0.0001, η² = 0.994). Furthermore, MANCOVA findings revealed significant differences between the experimental and control groups in the subcomponents of mood status, including anxiety (F = 24.136, p < 0.001), depression (F = 13.869, p = 0.001), fatigue (F = 7.807, p = 0.008), confusion (F = 27.566, p < 0.001), anger (F = 20.662, p < 0.001), and vigor (F = 30.461, p < 0.001). Conclusion: Acceptance and commitment therapy was effective in improving mood status among women with postpartum depression. The intervention reduced anxiety, depression, anger, fatigue, and confusion while enhancing positive mood and psychological flexibility.