Research has found that the risk for developing OCD is not only due to the genes we inherit from our parents, but also from environmental factors. However, it is unclear precisely which factors increase this risk, and by how much. By exploring how genetic and environmental factors interact further, it may be possible to ultimately diagnose and treat OCD earlier and faster.

Dr. Mataix-Cols and his team will recruit a large number of identical twin pairs (who share the same exact genes) where one twin has OCD and one does not – with the goal of understanding whether something in the environment led to OCD developing. The team will access a vast amount of early-life and medical information about these twin pairs using the unique Swedish nationwide registries. They will also build a database of biological samples from each participant, including samples that were taken at birth for the Swedish phenylketonuria (PKU) screening biobank. The team will then analyze this data to identify the environmental variables that increase risk for developing OCD. This research project could unlock new information about why certain people develop OCD, and even lead to knowledge that would allow us to prevent OCD from taking hold in the first place. As of November 2022, the team has recruited 18 pairs (36 individuals) of the target 50 pairs of discordant twins.