Obsessive-compulsive disorder (OCD) affects 1% to 3% of the population. While its exact causes remain elusive, research has consistently pointed to a strong genetic component in its development. A recent study from Daniel Geller, MD, Founder and Director of Research in the Pediatric Psychiatry Obsessive-Compulsive and Tic Disorder (OCD/Tic) Clinical and Research Program, and Mia Grossman, MD sheds light on the familial transmission of OCD, particularly in cases of OCD with pediatric onset.
This study evaluated the familial risk of OCD and common comorbid psychiatric illnesses in first-degree relatives of probands with a primary diagnosis of pediatric-onset OCD. The researchers directly evaluated 130 youth with OCD, along with their 133 unaffected siblings, 241 parents, and 49 pediatric controls without OCD, using structured diagnostic interviews and clinical corroboration.
Elevated Rates of Psychopathology in First-Degree Relatives
The findings revealed markedly elevated rates of anxiety, mood, disruptive behavior, and tic disorders among the probands with OCD. In siblings, the rates of these disorders were higher than observed in the unaffected controls but were lower than in probands with pediatric-onset OCD, suggesting a shared familial vulnerability to a range of psychiatric disorders.
One of the most striking findings was the high prevalence of OCD among first-degree relatives, with 26% of the relatives meeting criteria for OCD, a significantly higher rate than reported in studies of adult-onset OCD. Additionally, 9% of first-degree relatives had chronic tics or Tourette’s disorder, and 21% met the criteria for attention-deficit/hyperactivity disorder (ADHD).
Clinical Implications and Future Research
These results underscore the strong familial component of OCD, particularly in cases of pediatric onset. The elevated rates of OCD and related conditions among first-degree relatives suggest a shared genetic vulnerability that manifests in various forms of psychopathology. The study’s findings align with previous research indicating that early-onset OCD may represent a more familial subtype of the disorder. This subtype may be characterized by a higher genetic loading, leading to increased vulnerability not only to OCD but also to other neurodevelopmental and neuropsychiatric conditions.
From a clinical perspective, the findings underscore the importance of comprehensive assessments and early interventions for children and adolescents with OCD. Identifying and addressing comorbid conditions in probands and their family members may improve treatment outcomes and overall quality of life.
Furthermore, the study’s results emphasize the need for increased awareness and support for families affected by OCD. Recognizing the familial burden and providing appropriate resources can aid in early detection and appropriate management of the disorder.
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Geller DA, Grossman M. A Family Genetic Study of Obsessive Compulsive Disorder in Youth. J Atten Disord. 2024 Mar;28(5):639-647.
