OCD [genetic explanation]

Question 1

How does the diathesis-stress model link to OCD?

Answer 1

Candidate genes create an inherited vulnerability for OCD, but environmental stress is needed to trigger the condition

Question 2

How did Lewis first infer that OCD may be genetic?

Answer 2

He observed his OCD patients:
37% had parents with the disorder
21% had siblings with the disorder

Question 3

What are the genes that create a vulnerability for OCD?

Answer 3

Candidate genes

Question 4

Which system are some of the candidate genes involved in?

Answer 4

The serotonin system

Question 5

OCD is caused by multiple genes, it is __________

Answer 5

Polygenic

Question 6

What is polygenic?

Answer 6

It is caused by multiple genes

Question 7

How many genes did Taylor discover to be involved in OCD?

Answer 7

230

Question 8

What is the impact of certain OCD genes being involved in the action of dopamine and serotonin?

Answer 8

They are both mood regulating neurotransmitters, which can explain some emotional characteristics such as anxiety and depression

Question 9

The origin of OCD has different causes in different people, it is ____________

Answer 9

Aetiologically heterogeneous

Question 10

What does it mean that OCD is aetiologically heterogeneous?

Answer 10

Different genes may cause the same disorder in different people

Question 11

What impact does being aetiologically heterogeneous have on OCD?

Answer 11

There is evidence to suggest that different groups of genes may cause the different variations of the disorder, such as hoarding or religious obsession

Question 12

What is the supporting evidence for the genetic explanation of OCD?

Answer 12

NESTADT found that 68% of identical twins shared OCD as opposed to 31% of non-identical
= there is definitely a genetic element

Question 13

Why is Nestadt’s research not the strongest for support?

Answer 13

Not 100% of the identical twins shared the disorder, despite them having identical DNA, therefore there must be an environmental trigger as well

Question 14

Why isn’t the genetic explanation very useful for real life?

Answer 14

Psychologists cannot identify all the genes involved due to different genetic variations, therefore it has little predictive value

Question 15

What is an alternative argument for an external cause of OCD?

Answer 15

It is triggered by environmental factors [diathesis-stress model]
CROMER found that 50% of OCD patients had a traumatic event in their life
= cannot be purely genetic

Question 16

Why is it suggested that the environmental cause should be more focused on?

Answer 16

It is easier to do something about preventing the disorder than with the genetic explanation

Question 17

How do the candidate genes for OCD affect the serotonin system?

Answer 17

It increases the reuptake of serotonin into the per-synaptic neuron, decreasing the amount of serotonin that is available for normal neuronal communication