Given the limited state of knowledge about the pathophysiological pathways important for the manifestation of OCD, it is premature at this time to restrict focus on the association of specific candidate genes with OCD. Instead, a GWAS with a sample of sufficient size is the most promising approach for the identification of genomic regions that most likely harbor OCD risk genes. Once these regions have been identified, then more informed candidate gene studies could be undertaken. Given the variability of recurrence risks and the results from the most recent twin study, it is clear that, like other neuropsychiatric conditions, OCD is etiologically heterogeneous.
