Between- and within-person relations between treatment modules and symptom improvements across six randomized...

Most youth psychotherapies contain multiple treatment elements; little is known about their relative effectiveness. We assessed symptom improvements associated with treatment elements, represented by modules within modular psychotherapy.

Data from six clinical trials of the modular approach to therapy for children with anxiety, depression, trauma, or conduct problems modular psychotherapy were combined (N = 490; 5,403 sessions; 6-15 years) to test effects of modules grouped into seven common treatment principles: feeling calm (e.g., relaxation strategies), increasing motivation (e.g., contingency management), repairing thoughts (e.g., cognitive restructuring), solving problems (e.g., problem solving), trying the opposite (e.g., exposure), engagement/psychoeducation (e.g., building rapport), and future planning (e.g., planning skill use). Multilevel models with autoregressive covariance controlled for previous symptoms, session number, and baseline symptoms; accounted for temporality with each session occurring prior to associated outcomes; importantly, we modeled associations between outcomes and between- and within-person use of treatment principles. Measures included weekly youth- and caregiver-reported internalizing, externalizing, and total symptoms, plus idiographic top problems.

A between-person effect linked future planning (Bs = -.369 to -.368; ps < .05) to better outcomes. Better within-person effects were observed for increasing motivation (Bs = -0.087 to -0.057; ps < .05), trying the opposite (Bs = -.087 to -.056; ps < .05), and future planning (B = -0.146; p < .001). Six outcomes showed worse within-person effects for engagement/psychoeducation (Bs = .036-.099; ps < .05); efforts to build engagement drove this finding; those efforts were associated with less use of skills-focused principles.

Increasing motivation, trying the opposite, and future planning were associated with especially good outcomes; therapists' engagement attempts were associated with less focus on skill building and poorer immediate outcomes. Results may inform youth psychotherapy decision-making research and practice. (PsycInfo Database Record (c) 2025 APA, all rights reserved).