Genes are involved in individual vulnerability to OCD. Lewis conducted a classic study where he observed his OCD patients, 37% had parents with OCD, 21% had siblings with OCD. This suggests that OCD runs in families, although its most likely that vulnerability to OCD runs from generation to generation rather than OCD. According to the diathesis stress model certain genes leave some people more likely to develop a mental disorder but it’s not certain. Some environmental stress (experience) is necessary to trigger the condition.
Candidate genes
Researchers have found candidate genes which create vunerability for OCD. Some of the genes are involved in regulating the development of the serotonin system. eg. The gene 5HTI-D beta is implicated in the transport of serotonin across synapses.
OCO is polygenic
Its caused by a combination of genetic variations that together significantly increase vulnerability. Taylor analysed findings of previous studies and found that up to 230 different genes may be involved in OCD. Genes studied include those associated with the action of dopamine and serotonin - both are believed to have a role in regulating mood.
Different types of OCD
Aetiologically heterogenous means the origins of OCD vary from person to person. There is evidence to suggest that different types of OCD may be the result of particular genetic variations, hoarding disorder or religious obsession.
