Predicting Internalizing Behavior in Adolescents Based on Childhood Trauma and Alexithymia with the Mediating Role of Cognitive Fusion

Background: Studying internalizing behavioral problems in adolescents is essential for early diagnosis, prevention of long-term psychological consequences, and improvement of their overall mental health. This study aimed to predict internalizing behavior in adolescents based on childhood trauma and alexithymia with the mediating role of cognitive fusion.

Materials and Methods: The research method was descriptive-correlational and based on structural equation modeling. The statistical population consisted of all female adolescents studying in the second cycle of secondary education in public schools in Karaj during the 2025–2026 academic year. From this population, 250 female students were selected as the sample using convenience sampling. To collect data, in addition to a researcher-made demographic information checklist, the Internalizing Behavior Questionnaire (Achenbach, 1991), the Childhood Trauma Experience Questionnaire (Bernstein et al., 2003), the Alexithymia Questionnaire (Bagby et al., 1994), and the Cognitive Fusion Questionnaire (Gillanders, 2014) were used. The data were analyzed using Pearson correlation and structural equation modeling with the bootstrap method through SPSS and AMOS software.

Findings: The results showed that the direct effects of childhood trauma (β = 0.52, p < 0.011), alexithymia (β = 0.31, p < 0.015), and cognitive fusion (β = 0.34, p < 0.018) on internalizing behavioral problems were significant. The results also showed that cognitive fusion had a significant mediating role in the relationship between childhood trauma and internalizing behavioral problems (b = 0.46, p < 0.05), as well as in the relationship between alexithymia and internalizing behavioral problems in female adolescents (b = 0.35, p < 0.05). In addition, the final research model had a desirable fit (RMSEA = 0.067, P > 0.05).

Conclusion: Based on the findings of this study and the importance of the role of childhood trauma and alexithymia in internalizing behavioral problems among female adolescents, it is suggested that families, as well as authorities responsible for promoting mental health in society, use education on behavioral and parenting methods, while considering the mediating role of cognitive fusion, to prevent the development of behavioral problems in the future.