Exposure-based cognitive-behavioural therapy via the Internet and as bibliotherapy for somatic symptom disorder and illness anxiety disorder: randomised controlled trial

Background In DSM-5 two new diagnoses, somatic symptom disorder (SSD) and illness anxiety disorder (IAD), have replaced DSM-IV hypochondriasis. There are no previous treatment studies for these disorders. Cognitive-behavioural therapy (CBT) delivered as therapist-guided or unguided internet treatment or as unguided bibliotherapy could be used to increase treatment accessibility. Aims To investigate the effect of CBT delivered as guided internet treatment (ICBT), unguided internet treatment (U-ICBT) and as unguided bibliotherapy. Method A randomised controlled trial (RCT) where participants (n = 132) with a diagnosis of SSD or AD were randomised to ICBT, U-ICBT, bibliotherapy or to a control condition on a waiting list (trial registration: Clinicaltrials.gov identifier NCT01966705). Results Compared with the control condition, all three treatment groups made large and significant improvements on the primary outcome Health Anxiety Inventory (between-group d at post-treatment was 0.80-1.27). Conclusions ICBT, U-ICBT and bibliotherapy can be highly effective in the treatment of SSD and AD. This is the first study showing that these new DSM-5 disorders can be effectively treated.