What’s left feels right Studies in obsessive-compulsive disorder (OCD) and body integrity identity disorder (BIID)

Over the last decade the nosology status of obsessive-compulsive and related disorders has been topic of debate. Whereas in DSM-IV (Diagnostic and Statistical Manual of Mental Disorders IV) obsessive-compulsive disorder (OCD) was classified as an anxiety disorder, in DSM-V it is classified as a separate entity with compulsivity as the main symptom. The first part of this thesis consists of studies that contributed to this debate, investigating the prevalence of obsessions in the general population, the co-occurrence of addiction and OCD and neuropsychological correlates of hoarding disorder.
The second part of this thesis reveals the features Body Integrity Identity Disorder (BIID). BIID is an uncommon and infrequently studied disorder in which patients have the all-consuming desire to be either paralyzed or amputated. BIID patients from all over the world were questioned in order to obtain the most specific phenotype possible and to study paraphilic behaviors and thoughts co-morbid to the disorder. Moreover, neural correlates of BIID were studied using MRI (magnetic resonance imaging). The last chapter integrated results in order to provide a comprehensive description of BIID symptomatology.