“…Research on alliance between adolescent patients and their therapists is still scarce [ 19 , 20 ] and there is large methodological variability between the studies, e.g., studying a wider set of relational variables instead of focusing on alliance, using different alliance measurements or information sources, and variety of the timing of alliance measurement [ 21 , 22 , 23 ]. Yet, therapeutic alliance has been found to be an important treatment outcome predictor also with adolescents [ 19 , 22 , 24 , 25 ]. Studies on youth alliance have failed to fully support the three-factor model, suggesting that features of the alliance are less differentiated at a younger age, and instead propose a single-factor solution [ 26 , 27 , 28 , 29 ].…”