Enhancing Theory of Mind in Adults with ADHD: A Comparative Study of Metacognitive and Transdiagnostic Therapies

Purpose: This study aimed to assess the effectiveness of Metacognitive and Transdiagnostic Therapies in Theory of Mind in Adults with ADHD. Methodology: This study employed a semi-experimental design with a pre-test and post-test control group structure aimed at assessing the effects of two interventions on adults with ADHD symptoms. The population included all adults with diagnosed ADHD symptoms in 2024, referred from psychology and psychiatric centers in Damavand city. Purposive sampling was used to select participants. A sample of 45 patients was selected and randomly divided into intervention (MCT, n = 15), (MDT, n = 15), and control (n = 15) groups. The experimental groups underwent eight (MCT) sessions and ten (MDT) sessions (90-minute sessions per week), and the control group did not receive any intervention. The research instruments included the S-ADHD (Connors et al., 1999) and Mind Reading" test (Baron-Cohen et al., 2001). Univariate and multivariate analyses of covariance (ANCOVA) and Bonferroni post hoc tests were conducted using SPSS-27. Findings: results indicate a significant difference between the control group and both the metacognitive and meta-diagnostic therapy groups in improving the theory of mind (P<0.001). This suggests that both therapies effectively increased theory of mind compared to no treatment. Additionally, there was a significant difference between the two treatment groups themselves (P<0.05), with the meta-diagnostic therapy group demonstrating a greater effect—reflected by a mean difference of 4.45—on the theory of mind of adults with ADHD symptoms. Conclusion: Overall, the findings indicate that both metacognitive and transdiagnostic (meta-diagnostic) therapies significantly improve the theory of mind in adults with ADHD symptoms. However, transdiagnostic therapy was found to be more effective than metacognitive therapy. The improvements resulting from both approaches enable participants to develop a deeper and more accurate understanding of mental states, which enhances their ability to regulate social interactions and manage emotions effectively.