The Nordic OCD & Related Disorders Consortium (NORDiC) is an NIH-funded genetic study of obsessive-compulsive disorder (OCD) across Norway, Sweden, Denmark and Finland. We aim to collect the world’s largest richly phenotyped and genotyped sample of OCD cases (N = 10,000) in order to discover genetic and environmental factors that presumably interact to cause OCD. Key colleagues are located in each of the Nordic countries.
OCD is a major cause of disability, yet its etiology is unknown and existing treatments are suboptimal. There is a pressing need to understand the causal mechanisms implicated in OCD in order to improve clinical outcomes and to reduce morbidity and societal costs. Specifically, we need a large-scale, etiologically informative genetic study integrating carefully measured symptoms and genetic and environmental factors that presumably interact to cause the condition. We thus formed NORDiC to collect the world’s largest richly phenotyped and genotyped sample of OCD cases (N = 10,000). We have designed a rapid and cost-efficient strategy to markedly increase the worldwide sample size for OCD by capitalizing on unique Nordic resources. These samples will provide a wealth of treatment outcome and long-term follow-up data, providing an opportunity to identify predictors of clinical outcome. Finally, we will use a novel comparative genomic approach to interpret these data, capitalizing on canine compulsive disorder, an animal model with high face and construct validity.
NORDiC will answer a number of key questions regarding OCD biology, etiology and treatment. How does OCD relate to other psychiatric disorders? Do early-onset, tic-related and symptom dimensions possess distinct genetic origins? Is there a relationship between cumulative genetic risk and response to particular forms of treatment? We expect this study to bring us closer to converting this idiopathic disorder into a pathophysiologically defined disease, nominate potential drug targets and demonstrate the utility of the comparative genomics approach for other complex biomedical traits.