OCDTWIN-Project

Obsessive-compulsive disorder (OCD) is a relatively common psychiatric disorder that affects 1-3% of the population and often begins early in life. OCD can lead to high levels of individual distress and impairment in many areas of life, such as education and work, as well as other health problems. On a societal level, the disorder causes high socio-economic costs.

Given these known consequences and impairments and the frequent chronic course, there is a clear consensus that we should try to prevent the onset of OCD or, if this is not possible, intervene as early as possible to prevent long-term medical and socioeconomic consequences. The causes of OCD are still unknown. However, until we know more about the causes of OCD, the development of prevention strategies or more effective treatments will be severely limited and likely slow.

It is generally accepted that OCD runs in families and is a partially genetic disorder. However, at least 50% of the risk of developing OCD cannot be explained by genetic factors, but by unique environmental factors/exposures. Since it is assumed that monozygotic (MZ) twins are genetically identical and share 100% of their genes and the pairs also grow up together under identical conditions (shared environment), the discordance with regard to OCD (one twin has OCD, but his co-twin does not) within an MZ pair can only be explained by different environmental experiences of the two siblings. For this reason, the study of MZ twin pairs with discordance for OCD offers a unique opportunity to generate new insights into the potentially modifiable causes of the disorder.

OCDTWIN is a cooperation project between MSH Hamburg and the Stockholm Karolinska Institutet (KI) in which MZ twin pairs with discordance for OCD are sought throughout Germany in order to identify specific environmental risk factors for the development of the disease. In Germany, recruitment is supported by OCD Land.
More information about OCD Land can be found here “.

Data collection includes biological samples (blood, saliva, urine, stool, hair and brain imaging data) as well as clinical and questionnaire data. Participation includes two days of testing in Hamburg. Participants will be compensated for their participation and the travel and hotel costs arising from the study visit will be covered. If it is not possible to travel to Hamburg, participation is also possible from a distance (telephone interview, biological samples and questionnaires by post).