Explanations of OCD

Question 1

Biological approach

Answer 1

1. Genetic explanation
2. Neural explanation

Question 2

Genetic explanation

Answer 2

Lewis (1936)
* found that in his OCD patients, 37% had parents with OCD and 21% has siblings with OCD
* certain genes cause vulnerability to OCD- candidate genes
* OCD is polygenic- its not caused by a single gene but a combination of genetic variations
Taylor (2013)
* found evidence that up to 230 genes may involved in OCD - includes genes that regulate dopamine and serotonin levels
* origins of OCD is heterogenous- it varies from one person to another
* one group of genes may cause OCD for one person but a different group of genes may cause the disorder in another person

Question 3

Neural explanation

Answer 3

Role of serotonin- reduction in the functioning of serotonin system in the brain has been implicated in OCD and causes a person to experience low mood
* OCD is characterised by poor decision making
* this has been associated with the abnormal functioning of the lateral of the frontal lobes of the brain

Question 4

Evaluation

Answer 4

+ Support from twin studies
- Doesnt consider importance of environmental factors
- Links to depression
- No cause and effect

Question 5

+ Support from twin studies

Answer 5

• research evidence supports the suggestion that OCD is due to a genetic causes
• twin studies (Nestadt et al, 2010) found that 68% of identical (MZ) twins shared OCD as opposed to 31% of non-identical twins
• other research implies that if you have a family member with OCD you are 4x more likely to develop it than someone without

Question 6

- Doesnt consider environmental factor

Answer 6

• Genetic explanation doesnt consider the importance of environmental factors that may contribute to the development of OCD
• in a study by Cromer et al (2007) it was found that over half the ppts studied had experienced a traumatic experience in the past ehich led to the OCD

Question 7

- Links to depression

Answer 7

• many people with OCD also have depression
• know as co-morbidity (having two disorder together)
• neural explanations relating to serotonin are difficult to draw conclusions and isolate the differences and treat the disorder

Question 8

-No cause and effect

Answer 8

• neural explanations cannot imply cause and effect
• it lacks internal validity
• they only show a link between serotonin and OCD (relationship)