Comparative Efficacy and Acceptability of Transdiagnostic Psychotherapies for Emotional Disorders: Protocol for a Network Meta-Analysis of Randomized Controlled Trials.

backgroundEmotional disorders-primarily anxiety and unipolar depressive disorders-are highly prevalent, disabling, and frequently comorbid. Disorder‑specific cognitive behavioral therapy (DS‑CBT) is considered a gold standard treatment, yet it can be inefficient in the context of high comorbidity and service constraints. Transdiagnostic psychotherapies that target shared maintaining mechanisms (eg, emotion dysregulation and neuroticism) have been developed, including the Unified Protocol, transdiagnostic behavior therapy, emotion regulation therapy, and various transdiagnostic internet-delivered cognitive behavioral therapy protocols. Recent meta-analyses suggest that transdiagnostic interventions are effective or likely effective, but a comprehensive comparative evaluation across different transdiagnostic protocols, DS‑CBT, other evidence‑based psychotherapies, and control conditions is lacking.

objectiveThis study aims to conduct a network meta-analysis (NMA) to compare the efficacy and acceptability of various transdiagnostic therapies (eg, the Unified Protocol, transdiagnostic behavior therapy, and emotion regulation therapy), DS-CBT, other evidence-based active therapies (eg, acceptance and commitment therapy, behavioral activation, and mindfulness-based cognitive therapy), and control conditions (waitlist or care as usual) in improving symptoms in adults with anxiety and/or depressive disorders and generate a probabilistic ranking of their efficacy.

methodsThis meta-analysis will include randomized controlled trials from PubMed, Embase, PsycInfo, and the Cochrane Library, complemented by existing meta‑analytic research domain databases for depression and anxiety. Eligible participants are adults (≥18 years) with a principal diagnosis of anxiety and/or unipolar depressive disorder according to established diagnostic classification systems (eg, any version of the Diagnostic and Statistical Manual of Mental Disorders or International Classification of Diseases, 10th or 11th revisions) or scoring above a validated cutoff on anxiety or depression scales. Primary outcomes are continuous measures of anxiety and depressive symptom severity at the posttreatment time point; secondary outcomes include study dropout (acceptability) and response or remission where available. We will perform random-effects network meta-analyses within a frequentist framework using the netmeta package in R to estimate relative treatment effects and P scores for treatment rankings and examine transitivity and consistency. We will conduct additional Bayesian NMAs as sensitivity analyses using the surface under the cumulative ranking curve for ranking.

resultsAs of September 2026, the literature search has been completed, and title and abstract screening is ongoing. Data analysis will be conducted in late 2026. We expect the meta-analysis to be completed and submitted for publication by the end of 2026, with results expected to be published in early 2027.

conclusionsThis NMA will provide comprehensive comparative evidence on the efficacy and acceptability of transdiagnostic psychotherapies for emotional disorders, which can inform clinical decision-making and guideline development.

trial registrationOSF Registries osf.io/p8957; https://osf.io/p8957/overview. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/104791.