Heritability of obsessive-compulsive symptom dimensions

Area of Science:

• Psychiatry
• Behavioral Genetics
• Quantitative Genetics

Background:

• Obsessive-compulsive symptoms (OCS) exhibit significant patient heterogeneity.
• Genetic factors influence OCS, but the heritability of specific symptom dimensions remains unclear.
• Phenotypic heterogeneity raises questions about shared vs. specific genetic influences on OCS dimensions.

Purpose of the Study:

• To investigate the heritability of OCS symptom dimensions.
• To determine the extent to which genetic and environmental factors contribute to OCS dimensions.
• To explore shared and specific genetic influences underlying OCS symptom dimensions.

Main Methods:

• Utilized a population sample of 1,383 female twins from the Virginia Twin Registry.
• Measured OCS using a 20-item Padua Inventory questionnaire.
• Applied multivariate genetic models to three identified OC symptom dimensions (Rumination, Contamination, Checking) after factor analysis.

Main Results:

• A multivariate common pathway model best described the data, indicating a shared latent factor for OC behavior.
• The common factor for OC behavior was explained by 36% genes and 64% environmental factors.
• The Contamination dimension showed unique genetic influence, suggesting it as a relatively independent dimension.

Conclusions:

• A broad obsessive-compulsive behavioral phenotype exists, influenced by both genetic and non-shared environmental factors.
• Specific genetic and environmental factors underlie the Contamination dimension.
• The Contamination dimension may be valuable for identifying genetic susceptibility loci for OCS.