Genetic Explanation Of OCD AO3

Question 1

✅ What evidence supports the genetic influence on OCD?

Answer 1

Nestadt et al. (2010) found that 68% of identical twins (who share 100% of their genes) both had OCD, compared to 31% of non-identical twins (who share around 50% of their genes). This suggests a genetic component to OCD because the closer the genetic relationship, the higher the likelihood of both individuals developing OCD.

Question 2

✅ How does the study by Grootheest et al. (2005) support a genetic explanation for OCD?

Answer 2

Grootheest et al. (2005) found that OCD starting in childhood was more likely to have a genetic cause than OCD that began in adulthood. This supports the idea that genetics may play a more significant role in early-onset OCD, while environmental factors may have a greater influence on adult-onset OCD.

Question 3

❌ How does the variation in OCD symptoms between family members challenge the genetic explanation?

Answer 3

If OCD were purely genetic, family members with OCD should show similar symptoms. However, symptoms can differ widely (e.g., one person obsessively cleans while another arranges objects), suggesting that environmental factors may also play a role in shaping the specific symptoms of OCD.

Question 4

❌ What does the genetic explanation fail to account for in OCD?

Answer 4

The genetic explanation does not account for why some individuals develop OCD without a family history of the condition or why some with a genetic predisposition never develop OCD. This suggests that genetics may provide vulnerability, but environmental triggers are needed for OCD to develop.