Research about the genetics of OCD and related disorders continued to thrive, as scientists sought the basic biological markers that could contribute to OCD developing. Family studies—involving patients and their relatives—are especially important in this type of research, as they can provide valuable information about whether—and how—conditions run in families.
Dr. Rosario and her team explored the genetic transmission of OCD and the related disorders, Tourette syndrome and chronic tics, by carrying out a genetic study on 106 people with early-onset OCD (before age 14), 44 people without OCD, and their relatives (465 in total). Through detailed interviews, the team found that the mean age of onset for OCD symptoms among their sample was 6.7 years of age, and that there were high comorbidity rates with Tourette syndrome (33%) and chronic tics (13.2%). Compared to relatives of people without OCD, relatives of youths with OCD had a higher likelihood of having OCD and chronic tics. A comorbid diagnosis of tics in relatives was the best predictor of their diagnosis of OCD. Finally, a significant correlation between the ages of onset in youths with OCD and their relatives with OCD was found. This study provided evidence for childhood-onset OCD as a disorder that runs in families—the earlier the onset of symptoms, the higher the risk that a family member also has OCD and/or a tic disorder. This study contributed to the genetic research on OCD, and served as an important clinical finding when taking the risk of high family accommodation during treatment into account.
* Rosario-Campos, M.C., Leckman, J.F., Curi, M., Quatrano, S., Katsovich, L., Miguel, E.C., & Pauls, D.L. (2005). A family study of early-onset obsessive compulsive disorder. American Journal of Medical Genetics Part B (Neuropsychiatric Genetics), 136B, 92–97. doi:10.1002/ajmg.b.30149.