Comparing the effectiveness of metacognitive therapy and Barlow transdiagnostic treatment on the severity of clinical symptoms and experiential avoidance in patients with generalized anxiety disorder

Regarding the prevalence rate of Generalized Anxiety Disorder (GAD) and the importance of effective psychological interventions on treatment outcome, the present study aimed to compare the effectiveness of metacognitive therapy and Barlow transdiagnostic treatment on the severity of clinical symptoms and experiential avoidance in patients with generalized anxiety disorder. 

This cross-sectional study was done in 2020-2021. The samples were selected among patients diagnosed with GAD based on structured clinical interviews by clinical psychologists, who referred to three consultancy centers in Mashhad-Iran. Among these patients, 45 female patients with GAD diagnosis were selected by the convenience sampling method and divided randomly into three equal groups: Barlow transdiagnostic treatment, metacognitive therapy, and a control group. The experimental groups received the interventions in 12 forty-five-minute sessions (twice a week). The participants fulfilled The Seven-Item General Anxiety Disorder Scale (GAD-7) and Acceptance and Action Questionnaire-II (AAQ-II). The data were analyzed through descriptive statistics, covariance analysis, t-test, and SPSS version 21. 

The effect size of metacognitive therapy on experiential avoidance in patients with generalized anxiety disorder was 0.022, while this effect size was 0.255 in the transdiagnostic treatment. Also, the effect size of metacognitive therapy on anxiety in patients with generalized anxiety disorder was 0.019, while this effect size was 0.141 in the transdiagnostic treatment. 

Based on the findings, both metacognitive therapy and transdiagnostic treatment reduced anxiety and experiential avoidance in patients with generalized anxiety disorder, but transdiagnostic treatment decreased these symptoms more than metacognitive therapy.