Transdiagnostic versus disorder-specific and clinician-guided versus self-guided internet-delivered treatment for generalized anxiety disorder and comorbid disorders: A randomized controlled trial

TLDR

Generalized anxiety disorder can be effectively treated with either disorder‑specific cognitive‑behavior therapy or transdiagnostic CBT. The study aimed to compare the relative benefits of disorder‑specific versus transdiagnostic CBT and of clinician‑guided versus self‑guided delivery for GAD. A randomized controlled trial enrolled 338 GAD participants who received internet‑delivered TD‑CBT or DS‑CBT, each delivered in either clinician‑guided or self‑guided formats. Across all conditions, participants showed large reductions in GAD symptoms (Cohen’s d ≥ 1.48, >50 % improvement) and comorbid major depressive disorder (d ≥ 1.64, >45 % reduction), social anxiety (d ≥ 0.80, >29 % reduction), and panic disorder (d ≥ 0.55, >33 % reduction), with no meaningful differences between disorder‑specific versus transdiagnostic or clinician‑guided versus self‑guided approaches, highlighting the public‑health potential of TD‑CBT and SG‑CBT.

Abstract

Generalized anxiety disorder (GAD) can be treated effectively with either disorder-specific cognitive behavior therapy (DS-CBT) or transdiagnostic CBT (TD-CBT). The relative benefits of DS-CBT and TD-CBT for GAD and the relative benefits of delivering treatment in clinician guided (CG-CBT) and self-guided (SG-CBT) formats have not been examined. Participants with GAD (n=338) were randomly allocated to receive an internet-delivered TD-CBT or DS-CBT intervention delivered in either CG-CBT or SG-CBT formats. Large reductions in symptoms of GAD (Cohen's d ≥ 1.48; avg. reduction ≥ 50%) and comorbid major depressive disorder (Cohen's d ≥ 1.64; avg. reduction ≥ 45%), social anxiety disorder (Cohen's d ≥ 0.80; avg. reduction ≥ 29%) and panic disorder (Cohen's d ≥ 0.55; avg. reduction ≥ 33%) were found across the conditions. No substantive differences were observed between DS-CBT and TD-CBT or CG-CBT and SG-CBT, highlighting the public health potential of carefully developed TD-CBT and SG-CBT.