The Biological Approach to explaining OCD

Question 1

What are the 2 main explanations for OCD?

Answer 1

• genetic explanations
• neural explanations

Question 2

What is the genetic explanation?

Answer 2

• genes transmitted from our parents consist of DNA which codes for our physical & psychological features
• according to the DSM certain genes leave some people more likely to suffer from a mental disorder but some environmental stress triggers the condition

Question 3

How are candidate genes a genetic explanation for OCD?

Answer 3

• candidate genes are specific genes identified by researchers that create vulnerability for OCD
• some of these genes ae involved in regulating the serotonin system

Question 4

How is being polygenic a genetic explanation for OCD?

Answer 4

• polygenic means that OCD is not caused by only one gene but many are involved
• Taylor (2013) analysed findings from previous studies & found evidence that there may be up to 230 genes involved in OCD
• genes that are thought to be related to OCD are associated with the action or neurotransmitters like serotonin & dopamine which regulate mood

Question 5

How are different types of OCD a genetic explanation for OCD?

Answer 5

• a specific group of genes may cause OCD in one person but a different group may cause it in another person
• this that OCD is aetiologically heterogenous which means it’s caused by different things
• there is some evidence that suggests that different types of OCD may the result of certain genetic variations

Question 6

What is the neural explanation?

Answer 6

the idea that our physical & psychological features are determined by the behaviour of the nervous system, specifically the brain and certain neurons

Question 7

How is the role of serotonin a neural explanation for OCD?

Answer 7

• neurotransmitters transmit info from one neuron to another
• serotonin is a neurotransmitter which regulates our mood
• low levels of serotonin means that normal transmission of mood-related info doesn’t happen so our mood & other mental processes may be affected
• some cases of OCD can be explanation by a reduction in serotonin in the brain

Question 8

How are decision-making systems a neural explanation for OCD?

Answer 8

• some cases of OCD are associated with impaired decision making e.g. hoarding disorder
• this can be associated with the abnormal functioning of the lateral parts frontal lobes which are responsible for decision making & logical thinking

Question 9

Evaluation (of genetic explanations): There is good supporting evidence

Answer 9

• • evidence shows that some people are more vulnerable to OCD due to their genetic make-up
• Nestadt et al. reviewed previous twin studies & found that 68% of identical twins shared OCD in comparison with 31% of non-identical twins
• this suggest that there is a genetic influence on OCD

Question 10

Evaluation (of genetic explanations): Environmental risk factors

Answer 10

• other than genetic environmental factors can also trigger the risk of developing OCD
• e.g. Cromer et al. found that over half of OCD patients in the sample had experiences a traumatic event in their past & OCD was more severe in those with trauma
• this suggests that OCD is not entirely genetic-based
• this means there should be more focus on the environmental factors too since they play an important role in developing OCD

Question 11

Evaluation (of neural explanations): There is some supporting evidence

Answer 11

• evidence shows that there is the role of some neural mechanisms in OCD
• e.g. some antidepressants only work on the serotonin system by increasing its levels
• these drugs are effective in reducing OCD symptoms which suggests that serotonin is involved in OCD
• this means that understanding the neural basis of OCD has practical use in developing treatment for the symptoms

Question 12

Evaluation (of neural explanations): It’s not clear exactly what neural mechanisms are involved

Answer 12

• studies of decision making show that these neural systems are the same systems that function abnormally in OCD
• but research also identified that other brain systems may be involved sometimes but no system has been found that always plays a role in OCD
• this is a limitation for neural explanations as it means we can’t claim to understand neural mechanisms involved in OCD since there is no single system that is always involved