The Metacognitions Questionnaire-30 (MCQ-30) is widely used to assess dysfunctional metacognitive beliefs in both clinical and non-clinical adolescent populations. As no adolescent-specific validation has been conducted in Turkey, this study aimed to evaluate the reliability and validity of the MCQ-30 in Turkish adolescents. The sample included 338 adolescents aged 11–18 years who had applied to child and adolescent psychiatry outpatient clinics. Participants completed a sociodemographic and clinical data form, the MCQ-30, the Revised Children’s Anxiety and Depression Scale–Child Version (RCADS-CV), and the Strengths and Difficulties Questionnaire (SDQ) on an online platform. The mean age of the participants was 15.3 years (SD = 1.9). Among them, 111 (32.8%) were male and 227 (67.2%) were female. The Turkish MCQ-30 showed good to excellent internal consistency and a well-fitting five-factor structure, including positive beliefs (α = 0.820), negative beliefs about uncontrollability and danger (α = 0.885), cognitive confidence (α = 0.860), need to control thoughts (α = 0.947), and cognitive self-consciousness (α = 0.866). Internal consistency for the total score was excellent (α = 0.918), and test–retest analyses further supported the reliability of the scale. The MCQ-30 showed moderate-to-large positive correlations with measures of anxiety and depression, supporting its convergent validity. Additionally, the lack of a significant association with the SDQ prosocial behavior subscale provides evidence for its discriminant validity. These findings confirm the Turkish MCQ-30 as a reliable and valid measure of metacognitive beliefs in adolescents, supporting its use in clinical practice and research.
Öğütlü et al. (Thu,) studied this question.