Study Protocol for a Randomized Controlled Trial of the Efficacy of a Transdiagnostic Cognitive Behavior Therapy Model Delivered in Group Therapy for Anxiety Disorders

Abstract

Transdiagnostic protocols have been found to be effective in treating anxiety disorders by targeting shared transdiagnostic processes across diagnostic categories. The present study aims to introduce a novel group-based transdiagnostic cognitive behavioral therapy (tCBT) protocol developed for the treatment of anxiety disorders and to describe the design of a randomized controlled trial examining its efficacy. Participants are adults aged 18–65 years with a principal diagnosis of generalized anxiety disorder, social anxiety disorder, panic disorder, or other specified anxiety disorder, assessed via the Structured Clinical Interview for DSM-5 Disorders, Clinician Version (SCID-5-CV). A 2×3 mixed-design randomized controlled trial was employed, comparing tCBT (intervention group) with Rogerian supportive therapy (control group), with assessments at pretest, posttest, and 1-month follow-up. A 1-year follow-up was additionally initiated as an exploratory assessment, with data collection currently ongoing. Distress intolerance, intolerance of uncertainty and dysfunctional metacognitions are included as outcome variables given their roles as transdiagnostic factors across anxiety disorders. The Generalized Anxiety Disorder-7 Scale, Distress Tolerance Scale, Intolerance of Uncertainty Scale-12, Penn State Worry Questionnaire, Metacognitions Questionnaire-30, and Patient Health Questionnaire-9 are administered to assess outcome variables. The tCBT protocol consists of five modules delivered over eight weekly online sessions. This protocol is an adaptation of a group therapy format of the first transdiagnostic individual protocol developed and applied in Türkiye. The findings are expected to pioneer the development of further transdiagnostic protocols in Türkiye and to contribute to the broader transdiagnostic literature.