Genetic Explanations of OCD

Question 1

What are the 2 Biological Explanations of OCD?

Answer 1

• Genetic
• Neural

Question 2

What is the Genetic Explanation of OCD?

Answer 2

The idea that an individual inherits a genetic vulnerability that predisposes them to developing OCD via a genetic variation

Question 3

How many candidate genes did Taylor’s meta-analysis conclude may be involved in OCD?

Answer 3

230

Question 4

What are 2 candidate genes for OCD?

Answer 4

• COMT
• SERT

Question 5

What is the candidate gene COMT involved in?

Answer 5

The regulation of dopamine

Question 6

What is the candidate gene SERT involved in?

Answer 6

Serotonin transportation

Question 7

What does polygenic refer to in terms of OCD?

Answer 7

The fact that it is caused by a combination of genetic variations, not just one singular gene

Question 8

What are different genetic variations thought to cause in terms of OCD?

Answer 8

Different instances of OCD (e.g. hoarding, religious obsessions)

Question 9

What is meant by aetiologically heterogenous in terms of OCD?

Answer 9

Different combinations of genetic variations trigger OCD in different people

Question 10

What percentage of OCD sufferers did Lewis find had a parent with OCD?

Answer 10

37%

Question 11

In Nestadt’s Twin Study, what was the concordance rate for MZ twins compared to DZ twins?

Answer 11

68% compared to 31%

Question 12

Which study suggests that the environment also plays a role in the development of OCD?

Answer 12

Cromer, who found that over 50% with OCD had undergone a traumatic experience, and that OCD was more severe in those who had undergone more than one traumatic experience

Question 13

What kind of determinism does the Genetic Explanation of OCD exhibit?

Answer 13

Biological determinism, although it is not necessarily hard determinism

Question 14

Are genes likely to be the distal or proximal cause of OCD, and how can this be linked to the development of potential treatments?

Answer 14

The distal, root cause. A greater understanding of what genes are involved with OCD and what their roles are may aid the development of potential treatments (e.g. SSRI’s, which target serotonin, linking to the SERT candidate gene)

Question 15

Why do concordance rates in relation to OCD suggest that there are still other influences besides genetics involved?

Answer 15

Because the concordance rates are still lower than the degree of genetic relatedness. MZ twins share 100% of their DNA, and yet concordance rates are not 100%, meaning their must be other factors at play (e.g. the diathesis-stress model)