Comparison of the Effectiveness of Acceptance and Commitment Therapy and Schema Therapy on Dysfunctional Attitudes in Patients with Lung Cancer

Abstract

The present study aimed to compare the effectiveness of Acceptance and Commitment Therapy (ACT) and Schema Therapy on dysfunctional attitudes in patients with lung cancer. This quasi-experimental study employed a pretest–posttest control group design with a two-month follow-up and was conducted on 24 patients with lung cancer referred to the Sari Comprehensive Cancer Center in 2025. Participants were selected purposively and randomly assigned to ACT (n=8), Schema Therapy (n=8), and control (n=8) groups. Both interventions were delivered in eight 90-minute group sessions. Dysfunctional attitudes were assessed using the Weissman and Beck Dysfunctional Attitudes Scale. Data were analyzed using mixed analysis of variance in SPSS version 26. Mixed ANOVA revealed a significant time × group interaction effect on dysfunctional attitudes (F=4.55, p<0.01, η²=0.19). Both intervention groups showed significant reductions in dysfunctional attitudes at posttest and follow-up compared to the control group (p<0.05). Bonferroni post hoc comparisons indicated that ACT produced significantly greater reductions in dysfunctional attitudes than Schema Therapy (p<0.05). Both ACT and Schema Therapy effectively reduced dysfunctional attitudes in patients with lung cancer; however, ACT demonstrated superior effectiveness and may be considered a preferable psychological intervention in psycho-oncology settings.