In this paper, we report the results of the most recent genome-wide association study of OCD, the OCD Collaborative Genetics Association Study (OCGAS). Investigators at 8 research centers in the United States, including Brown University, Columbia University, Johns Hopkins University, Massachusetts General Hospital, Harvard School of Public Health, the National Institute of Mental Health, University of California Los Angeles, and the University of Southern California, conducted this collaborative study. The aim of the study was to identify common variants associated with OCD using an integrative analyses pipeline that involved association testing at both SNP and gene levels. The approach included OCD-affected patients (in a family-based analytic setting) with an early onset of the disorder (eighteen years and younger) who had been comprehensively assessed via an identical diagnostic approach at all recruitment centers.
