The Adolescent Psychotherapy Q-Set (APQ): A Validation Study

This article reports the validation of the Adolescent Psychotherapy Q-set (APQ), a newly developed instrument, adapted from the well-established Psychotherapy Q-Set (PQS) and the Child Psychotherapy Q-set (CPQ). The APQ aims to describe the psychotherapy process in the treatment of adolescents in a form suitable for quantitative comparison and analysis. The validation was conducted with the ratings of 70 audio-recorded youth psychotherapy sessions from a range of therapists, patients, and treatment stages, using two therapeutic approaches (Short-Term Psychoanalytic Psychotherapy and Cognitive Behavioral Therapy). Data analysis included intraclass correlation coefficients, Q-factor analysis, nonparametric mean differences, and Pearson correlations. Results suggest that the APQ has good levels of interrater reliability, is able to identify differences and similarities of two therapeutic approaches, and good convergent and discriminant validity with a widely-used measure of therapist behaviors (the Comparative Psychotherapy Process Scale). The APQ reported good levels of validity and reliability. It is hoped that it will contribute to new ways of investigating the mechanisms of therapeutic change for those working with adolescents.