- Studies of families have found that there is a genetic component that predisposes some individuals to having OCD
- Lenane (1990) 30% of 1st degree relatives in their study also had OCD
- If OCD is genetic, then if 1 MZ twin has OCD the other twin should also develop it.
- However the problem with alot of twin studies is that they often share the same environment and so conclusions cannot be made as to wether the concordance is due to biology or social factors
- There seems to be some sort of genetic cause however it may be a phenotype (which is only triggered…