Parent-only and parent–adolescent delivery of the Unified Protocol for adolescent emotional disorders: a preference-based non-randomised controlled study

Abstract Introduction: The Unified Protocol for Adolescents (UP-A) is a transdiagnostic treatment for adolescent emotional disorders, but its delivery typically requires direct adolescent participation, which may limit access for some families. We aimed to examine outcomes of parent-only UP-A (P-O) compared with treatment as usual (TAU), and to assess whether parent–adolescent UP-A (P-A) retained a clinical signal when selected in routine care. Method This assessor-masked, preference-based nonrandomised study enrolled 99 adolescents aged 12–17 years with emotional disorders who selected P-O, P-A, or TAU (33 per arm). Both active formats comprised 12 weekly group sessions using a culturally adapted UP-A. The primary outcome was posttreatment Clinical Global Impressions–Severity (CGI-S). Secondary outcomes included response, remission, and measures of symptoms, functioning, emotion regulation, and family processes. Analyses used augmented inverse-probability weighting and mixed-effects models with false-discovery-rate adjustment. Results At posttreatment, P-O was associated with lower CGI-S than TAU (adjusted mean difference, − 1.04; 95% CI, − 1.82 to − 0.42; p=.003), with the difference maintained at 3-month follow-up (− 1.18; 95% CI, − 1.96 to − 0.47; p=.002). P-A was also associated with lower CGI-S than TAU at posttreatment (− 0.58; 95% CI, − 1.13 to − 0.07; p=.027) and follow-up (− 1.02; 95% CI, − 1.61 to − 0.36; p=.001). Global functioning showed the most consistent secondary-domain differences. Direct P-O–P-A endpoint comparisons were nonsignificant. Conclusion Both active formats were associated with clinically meaningful improvement. Parent-only UP-A may provide an alternative when direct adolescent participation is not feasible, although randomised head-to-head trials are needed. Trial registration Chinese Clinical Trial Registry, ChiCTR2500097313 registered 17 February 2025.