biological approach to explaining OCD evaluation

Question 1

there is good supporting evidence for the biological approach to explaining OCD

Answer 1

there is evidence from a variety of sources for the idea that some people are vulnerable to OCD as a result of their genetic make-up

one of the best sources of evidence for the importance of genes is TWIN STUDIES

NESTADT ET AL (2010) received previous twin studies and found that 68% of identical twins shared OCD as opposed to 31% of non - identical twins

This strongly suggests genetics have an influence on OCD

Question 2

there are too many candidate genes - why is this a limitation for the genetic explanation

Answer 2

twin studies strongly suggest OCD is largely under genetic control, psychologists have been much less successful at pinning down all the genes involved

the consequence is that a genetic explanation is unlikely to ever be useful because ut provides little predictive value

Question 3

environmental factors can also cause OCD – why is this a limitation for the genetic explanation

Answer 3

environmental factors can also trigger or increase the risk of developing OCD (the diathesis-stress model)
e.g. Cromer et al found that over half the OCD patients in their sample had a traumatic event in their past, and that OCD as more severe in those with more than one trauma

This suggests that OCD cannot be entirely genetic in origin, at least not in all cases

It may be more productive to focus on the environmental causes because we are more able to do something

Question 4

there is some supporting evidence for the neural explanation for OCD

Answer 4

there is evidence to support the role of some neural mechanisms OCD

e.g. some antidepressants work purely on the serotonin system increasing levels of this neurotransmitter
Such drugs are effective in reducing OCD symptoms and suggests that the serotonin system is involved in OCD

Also, OCD symptoms form part of a number of other conditions that are biological in origin, for example, Parkinson’s Disease (Nestasdt et al)

This suggests that serotonin has a role in OCD

Question 5

it is not clear exactly what neural mechanisms are involved

Answer 5

studies of decision making gave shown that these neural systems are the same systems that function abnormally in OCD ( Caredini et al 2002)

However, research has also identified other brain systems that may be involved sometimes but no system has been found that always plays a role in OCD

we cannot therefore really clam understand the neural mechanisms involved in OCD

Question 6

we should not assume the neural mechanisms caused by OCD

Answer 6

there is evidence to suggest that various neurotransmitters and structures of the brain do not function normally in patients with OCD

However, this is not the same as saying that this abnormal functioning causes OCD. It could be the case that OCD causes these abnormal brain functioning