Obsessive-compulsive disorder (OCD) is a debilitating psychiatric disorder, yet its etiology is unknown and treatment outcomes could be improved if biological targets could be identified. Unfortunately, genetic findings for OCD are lagging behind other psychiatric disorders. Thus, 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, there is a need for a large-scale, etiologically informative genetic study integrating genetic and environmental factors that presumably interact to cause the condition. The Nordic countries provide fertile ground for such a study, given their detailed population registers, national healthcare systems and active specialist clinics for OCD. We thus formed the Nordic OCD and Related Disorders Consortium (NORDiC, www.crowleylab.org/nordic), and with the support of NIMH and the Swedish Research Council, have begun to collect a large, richly phenotyped and genotyped sample of OCD cases. Our specific aims are geared toward answering a number of key questions regarding the biology, etiology, and treatment of OCD. This article describes and discusses the rationale, design, and methodology of NORDiC, including details on clinical measures and planned genomic analyses.

中文翻译：

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北欧强迫症及相关疾病协会：基本原理，设计和方法。

强迫症（OCD）是一种使人衰弱的精神疾病，但其病因尚不清楚，如果可以确定生物学目标，则可以改善治疗效果。不幸的是，强迫症的遗传发现落后于其他精神疾病。因此，迫切需要了解与强迫症相关的因果机制，以改善临床结果并降低发病率和社会成本。具体而言，需要进行大规模的病因学遗传学研究，整合可能推测会引起该病的遗传和环境因素。北欧国家提供了详尽的人口登记资料，国家医疗保健系统以及活跃的强迫症专业诊所，为开展这项研究提供了沃土。因此，我们成立了北欧强迫症和相关疾病协会（NORDiC，www.crowleylab.org / nordic），并在NIMH和瑞典研究委员会的支持下，开始收集大量，表型和基因型的强迫症病例样本。我们的特定目标旨在回答有关强迫症的生物学，病因学和治疗的许多关键问题。本文介绍并讨论了NORDiC的原理，设计和方法，包括有关临床措施和计划的基因组分析的详细信息。