Emetophobia is defined as a specific phobia of vomiting, currently diagnosed as specific phobia “other” type in DSM-5 (American Psychiatric Association, 2013). Though there is a dearth of research conducted on emetophobia and its treatment, there is limited data from case studies (Hunter & Antony, 2009; Maack, Deacon, & Zhao, 2013) and one open trial of group therapy (Ahlen, Edberg, Di Schiena, & Bergström, 2014), providing initial evidence regarding the efficacy of targeted cognitive-behavioral treatment (CBT) in treating emetophobia. To date, no study has evaluated transdiagnostic CBT for emetophobia. Given suggestions that emetophobia frequently has a complex presentation, which shares elements with multiple anxiety disorder diagnoses, including specific phobia, panic disorder, obsessive–compulsive disorder, and generalized anxiety disorder, (e.g., Boschen, 2007; Veale, 2009; Veale & Lambrou, 2006), a transdiagnostic approach could prove promising. Transdiagnostic CBT has exhibited success in treating a range of anxiety disorders (Reinholt & Krogh, 2014) and in reducing comorbid symptoms more effectively than diagnosis-specific CBT (Norton et al., 2013). It was expected that a transdiagnostic treatment approach would be beneficial in treating emetophobia due to the treatment’s flexibility in targeting multiple features of anxiety disorders concurrently.
