Assessing psychological flexibility in adolescents: Validation of PsyFlex-A

Objective: To adapt and validate the Psy-Flex for the adolescent population (PsyFlex-A). The aim was to analyse the PsyFlex-A factor structure, reliability, the model's invariance between genders, and associations between the PsyFlex-A, sociodemographic variables, and other variables of interest. Method: The sample included 309 adolescents between 12 to 18 years old (M = 14.91) and a mean of 9.56 years of education. The participants completed a protocol comprising the PsyFlex-A and a set of other self-report measures assessing mindfulness skills (CAMM), cognitive fusion and experiential avoidance (AFQ-Y8), psychopathological symptoms (DASS-21), and the perceived quality of life and well-being (KidScreen-10). A subsample of 45 participants completed the PsyFlex-A four weeks after the first administration to conduct a test-retest reliability analysis. Confirmatory factor analyses (CFA) were used to assess the scale's structure. A multi-group CFA was conducted to determine the measurement invariance across genders. Reliability and validity were also analysed. Results: The PsyFlex-A presented a single-factor structure and model invariance between genders, suggesting that the results are comparable between males and females. Moreover, it revealed adequate internal consistency and test-retest reliability. It showed positive associations with mindfulness skills and quality of life and negative associations with cognitive fusion/experiential avoidance and psychopathological symptoms. Finally, significant gender differences were found, with boys revealing higher values of psychological flexibility than girls. Conclusion: The PsyFlex-A proved to be a valid and reliable instrument for assessing Portuguese adolescents' psychological flexibility skills. The PsyFlex-A may be used as a screening instrument in educational and clinical settings.