It is possible that some relatives with OCD may not have been identified with this ascertainment scheme. Low scores on the LOI can be observed in individuals having only a few obsessions and/or compulsions which consume significant time and cause considerable distress and result in a diagnosis of OCD. Thus, it is possible that some of the noninterviewed relatives could have scored low on the LOI yet still met criteria for a diagnosis of OCD. In should be noted, however, that these investigators did observe an increased rate of mental illness overall among the relatives of these OCD probands.
