title: A RCT of a transdiagnostic internet-delivered treatment for three anxiety disorders: examination of support roles and disorder-specific outcomes.
abstract: BACKGROUND
  Anxiety disorders share common vulnerabilities and symptoms. Disorder-specific treatment is efficacious, but few access evidence-based care. Administering transdiagnostic cognitive-behavioral therapy via the internet (iCBT) may increase access to evidence-based treatment, with a recent randomized controlled trial (RCT) providing preliminary support for this approach. This study extends those findings and aims to answer three questions: Is a transdiagnostic iCBT program for anxiety disorders efficacious and acceptable? Does it result in change for specific disorders? Can good clinical outcomes be obtained when guidance is provided via a Coach rather than a Clinician?
  
  
  METHODS
  RCT (N = 131) comparing three groups: Clinician-supported (CL) vs. Coach-supported (CO) vs. waitlist control (Control). Individuals met DSM-IV criteria for a principal diagnosis of generalized anxiety disorder (GAD), social phobia (SP) or panic disorder with or without agoraphobia (Pan/Ag). Treatment consisted of an 8-lesson/10 week iCBT program with weekly contact from a Clinician or Coach, and follow-up at 3-months post-treatment.
  
  
  RESULTS
  Outcomes for the pooled treatment groups (CL+CO) were superior to the Control group on measures of anxiety, depression and disability, were associated with medium to large effect sizes (Cohen's d = .76-1.44) (response rate = 89-100%), and were maintained at follow-up. Significant reductions were found on disorder-specific outcomes for each of the target diagnoses, and were associated with large effect sizes. CO participants achieved similar outcomes to CL participants at post-treatment, yet had significantly lower symptom severity scores on general anxiety, panic-disorder, depression and disability at follow-up (d = .45-.46). Seventy-four percent of CO and 76% of CL participants completed the program. Less than 70 minutes of Clinician or Coach time was required per participant during the program.
  
  
  CONCLUSIONS
  This transdiagnostic iCBT course for anxiety appears to be efficacious, associated with significant change for three target disorders, and is efficacious when guided by either a Clinician or Coach.
  
  
  BACKGROUND
  Australian New Zealand Clinical Trials Registry ACTRN12610000242022.
authors: CRUfAD, School of Psychiatry, University of New South Wales at St Vincent's Hospital, Sydney, Australia. luke.johnston@mq.edu.au
authors: Luke
authors: L
authors: Johnston
authors: Nickolai
authors: N
authors: Titov
authors: Gavin
authors: G
authors: Andrews
authors: Jay
authors: J
authors: Spence
authors: Blake F
authors: BF
authors: Dear
mesh_terms: D000328:Adult; D001008:Anxiety Disorders / Q000175:diagnosis* / Q000628:therapy*; D016022:Case-Control Studies; D015928:Cognitive Behavioral Therapy; D015897:Comorbidity; D003710:Demography; D005260:Female; D006801:Humans; D020407:Internet; D008297:Male; D010349:Patient Compliance; D012944:Social Support; D016896:Treatment Outcome