As genetic studies of OCD continued to gain interest, some researchers focused on genetic data collected from families of people with OCD.
This study by Dr. Mathews and her team led to a series of publications related to family genetics surrounding OCD, with some specifically focusing on early-onset OCD. Sheppard et al. (2010) focused on the prevalence of ADHD among people with early-onset OCD, as well as focusing on compulsive hoarding behaviors. With a sample of 155 participants with OCD without comorbid tic disorders from the US and Costa Rica, this study found that ADHD rates were high, and that hoarding behaviors and ADHD were associated. Katerberg et al. (2010) used symptom scores from 1,224 people with OCD and genetic heritability analyses in 52 families with someone who had OCD to explore OCD dimensions and how they are tied to genetics. This study found five fitting dimensions — taboo, contamination, doubts related to harm, rituals/superstition, and hoarding/symmetry — all of which showed a degree of heritability. Mathews et al. (2008) also focused on dimensions of OCD, but focused on a “core” symptom set related to obsessions. With a sample of 59 people with OCD and 125 of their family members, as well as 1,015 healthy controls, this study found a heritable component to obsessionality in both OCD and non-OCD samples, but that subtypes (in this case, contamination, repetition/doubt, checking, and “just-right” OCD)were not heritable. With a Costa Rican and US sample consisting of 92 family members (young people with OCD, including some with hoarding behaviors, and their families) Mathews et al. (2007) found a high degree of heritability for OCD symptoms. Chavira et al. (2008) compared presentations of OCD in 26 people with OCD from Costa Rica and 52 people with OCD from the US. While both samples had similar obsessive and compulsive symptoms, frequencies of symptoms, and age of onset, the US sample reported higher comorbidity rates with other disorders and higher OCD severity. Ross et al. (2011) analyzed the genetics of three Costa Rican families that had at least two people with OCD and found evidence for the role of chromosome 15q14 in being a factor for passing down OCD. This project contributed to the establishment of an international consortium to identify genetic causes behind OCD.
*Chavira, D. A., Garrido, H., Bagnarello, M., Azzam, A., Reus, V. I., & Mathews, C. A. (2008). A comparative study of obsessive-compulsive disorder in Costa Rica and the United States. Depression and Anxiety, 25(7), 609–619. doi:10.1002/da.20357
*Katerberg, H., Delucchi, K. L., Stewart, S. E., Lochner, C., Denys, D. A., Stack, D. E., Andresen, J. M., Grant, J. E., Kim, S. W., Williams, K. A., den Boer, J. A., van Balkom, A. J., Smit, J. H., van Oppen, P., Polman, A., Jenike, M. A., Stein, D. J., Mathews, C. A., & Cath, D. C. (2010). Symptom dimensions in OCD: item-level factor analysis and heritability estimates. Behavior Genetics, 40(4), 505–517. doi:10.1007/s10519-010-9339-z
*Mathews, C. A., Nievergelt, C. M., Azzam, A., Garrido, H., Chavira, D. A., Wessel, J., Bagnarello, M., Reus, V. I., & Schork, N. J. (2007). Heritability and clinical features of multigenerational families with obsessive-compulsive disorder and hoarding. American Journal of Medical Genetics. Part B, Neuropsychiatric Genetics: The Official Publication of the International Society of Psychiatric Genetics, 144B(2), 174–182. doi:10.1002/ajmg.b.30370
*Mathews, C. A., Greenwood, T., Wessel, J., Azzam, A., Garrido, H., Chavira, D. A., Chandavarkar, U., Bagnarello, M., Stein, M., & Schork, N. J. (2008). Evidence for a heritable unidimensional symptom factor underlying obsessionality. American Journal of Medical Genetics. Part B, Neuropsychiatric Genetics: The Official Publication of the International Society of Psychiatric Genetics, 147B(6), 676–685. doi:10.1002/ajmg.b.30660
*Ross, J., Badner, J., Garrido, H., Sheppard, B., Chavira, D. A., Grados, M., Woo, J. M., Doo, P., Umaña, P., Fournier, E., Murray, S. S., & Mathews, C. A. (2011). Genomewide linkage analysis in Costa Rican families implicates chromosome 15q14 as a candidate region for OCD. Human Genetics, 130(6), 795–805. doi:10.1007/s00439-011-1033-6
Sheppard, B., Chavira, D., Azzam, A., Grados, M. A., Umaña, P., Garrido, H., & Mathews, C. A. (2010). ADHD prevalence and association with hoarding behaviors in childhood-onset OCD. Depression and Anxiety, 27(7), 667–674. doi:10.1002/da.20691