Genetic explanation for OCD

Question 1

What does the genetic explanation of OCD suggest about relatives?

Answer 1

Genetic research has found that first degree relatives of people with OCD have a greater vulnerability of developing the disorder. Nestadt et al (2000) found that first degree relatives had a 12% chance of developing the disorder compared to a 3% risk in the general population.

Question 2

What are candidate genes in terms of the genetic explanation of OCD?

Answer 2

These genes are involved in regulating the production of the neurotransmitter serotonin that is also implicated in OCD.

Question 3

What are the candidate genes in terms of the genetic explanation of OCD?

Answer 3

SERT and COMT

Question 4

What is the SERT gene in terms of the genetic explanation of OCD?

Answer 4

If this is impaired, it leads to problems with the transport of the neurotransmitter serotonin. This ultimately leads to diminished levels of serotonin, which correlates with OCD.

Question 5

What research is there for the SERT gene?

Answer 5

In one study, a mutation of this gene was found in two unrelated families where 6 out of 7 members had OCD - Ozaki

Question 6

What is the COMT gene in terms of the genetic explanation of OCD?

Answer 6

In short, this gene regulates the production of another neurotransmitter called dopamine. An impaired COMT gene leaves too much dopamine in the synapse, resulting in some of the compulsive behaviours seen in patients of OCD.

Question 7

What research is there for the COMT gene?

Answer 7

Taylor (2013) has identified up to 230 candidate genes that may contribute to OCD, which ultimately suggests OCD is polygenic.

Question 8

Is there supporting research for the genetic explanation of OCD?

Answer 8

Nestadt’s review of twin studies found a concordance rate for OCD of 67% for identical twins but only 31% for fraternal twins.
The closer the genetic relationship to the sufferer, the greater the risk of developing OCD.

Question 9

Is the genetic explanation of OCD theoretically flawed?

Answer 9

Genes cannot be the only reason, or the concordance rate of identical twins would be 100%.
There must be environmental influences, like the imitation of role models.

Question 10

Is the genetic explanation of OCD scientific?

Answer 10

Genetics can be studied objectively using DNA analysis.
You could also trace back family history to find concordance rates.

Question 11

Is the genetic explanation for OCD biologically reductionist?

Answer 11

It ignores the role of early childhood trauma, or that obsessions and compulsions can be learnt via observation of parents.