title: Design challenges in transdiagnostic psychotherapy research: Comparing Transdiagnostic Behavior Therapy (TBT) to existing evidence-based psychotherapy in veterans with affective disorders.
abstract: BACKGROUND
  To address the limitations of disorder-specific approaches, newer transdiagnostic approaches to psychotherapy have been developed to provide a single treatment that is capable of addressing several, related disorders. However, the recruitment of multiple diagnoses presents many challenges to the traditional design of psychotherapy randomized controlled trials (RCTs).
  
  
  OBJECTIVE
  The goal of the manuscript is to present the challenges and rationale for designing a RCT for transdiagnostic treatment to inform and aid in the development of future investigations.
  
  
  METHODS
  A recently funded and ongoing RCT for Transdiagnostic Behavior Therapy (TBT) is used as an example to discuss the related design challenges. The TBT study involves the recruitment of 96 veteran participants with any of the following eight principal diagnoses: posttraumatic stress disorder, panic disorder, social anxiety disorder, obsessive compulsive disorder, generalized anxiety disorder, specific phobia, major depressive disorder, or persistent depressive disorder. Within the TBT study, participants will complete a semi-structured diagnostic interview and a series of transdiagnostic self-report measures to determine eligibility and assess baseline symptomatology. Qualifying participants will be randomized to TBT or control psychotherapy. Additional assessments will be completed at post-treatment and 6-month follow-up.
  
  
  CONCLUSIONS
  Due to the transdiagnostic nature of the sample, adjustments to the recruitment and randomization procedures, selection of measures, selection of control psychotherapy, and analysis plan were required. These adjustments have implications to future trials on transdiagnostic psychotherapy protocols as well as future research in line with the transdiagnostic focus of the National Institute of Mental Health's Research Domain Criteria (RDoC) funding strategy.
authors.affiliation: Mental Health Service, Ralph H. Johnson Veterans Affairs Medical Center, Charleston, SC, United States; Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC, United States. Electronic address: grosd@musc.edu.
authors.forename: Daniel F
authors.initials: DF
authors.lastname: Gros
mesh_terms: D001521:Behavior Therapy / Q000379:methods*; D015897:Comorbidity; D006801:Humans; D001523:Mental Disorders / Q000523:psychology / Q000628:therapy; D019964:Mood Disorders / Q000523:psychology* / Q000628:therapy*; D018579:Patient Selection; D011613:Psychotherapy / Q000379:methods; D012107:Research Design; D014728:Veterans / Q000523:psychology*
keywords: Comorbidity; Psychotherapy; RDoC; TBT; Transdiagnostic; Transdiagnostic Behavior Therapy