Psychopathology- Genetic explanation for OCD

Question 1

Genetic evidence has found that ____ degree relatives of people with OCD have a greater vulnerability of developing the disorder.

Answer 1

first

Question 2

_______ et al (2000) found that first-degree relatives (i.e. parents, siblings or children) of OCD sufferers had a 12% chance of developing the disorder compared to a 3% risk in the general population.

Answer 2

Nedstadt

Question 3

According to Nedstadt first degree relatives of OCD suffered have a __% chance of developing OCD compared to a _% risk in the general population

Answer 3

12
3

Question 4

What genes has research found to be responsible for OCD

Answer 4

Candidate genes

Question 5

What are some candidate genes involved in regulating and producing

Answer 5

Serotonin levels

Question 6

What neurotransmitter is implicated in OCD

Answer 6

Serotonin

Question 7

What does an impaired SERT gene lead to

Answer 7

Diminished levels of serotonin

Question 8

What did Ozaki et al find in relation to an impaired SERT gene
-its a study

Answer 8

The mutation of the gene was found in 2 unrelated families where 6 out of 7 members had OCD

Question 9

Ozaki found that:
The mutation of the SERT gene was found in _ unrelated families were _out of _ members had OCD

Answer 9

2
6
7

Question 10

What are the two impaired candidate genes that have been found responsible for OCD

Answer 10

SERT
COMT

Question 11

What neurotransmitter does the COMT gene regulate production of

Answer 11

Dopamine

Question 12

What happens to dopamine when an impaired COMT gene is present

Answer 12

Too much dopamine is left in the synapse

Question 13

What can too much dopamine present in a synapse lead to

Answer 13

Compulsive behaviours seen within patients with OCD

Question 14

How many candidate genes did Taylor identify that may contribute to OCD

Answer 14

230

Question 15

What does polygenic mean

Answer 15

A disorder caused by multiple genetic variants

Question 16

Why is OCD most likely polygenic

Answer 16

As there are so many candidate genes associated with it (230), which suggests it is most likely caused by multiple genetic variants

Question 17

What does the genetic explanation suggest about the development of OCD

Answer 17

That some people may inherit a genetic predisposition

Question 18

What concordance rate did Nedstadt identify in MZ twins for OCD

Answer 18

0.67 or 67%

Question 19

What concordance rate did Nedstadt identify in DZ twins for OCD

Answer 19

0.31 or 31%

Question 20

Evaluating the genetic explanation
-research from Nedstadt

Answer 20

Nestadt (2010) review of twin studies found a concordance rate of 0.67 (or 67%) for MZ (identical) twins but only 0.31 (or 31%) for DZ (fraternal) twins.

Hence, the closer the genetic relationship to a sufferer the greater the risk of developing OCD

This suggests that genetics are certainly involved in the transmission of OCD

Question 21

Evaluating the genetic explanation
-Theortical flaw with Nedstadt’s research

Answer 21

However, this research also demonstrates that genes cannot be the only factor in the development of OCD

Because, if genes were the only explanation then MZ twins would show 100% concordance in OCD. As this is not the case, there must also be environmental influences, like imitation of role models

Therefore the genetic explanation of OCD could be seen as theoretically flawed

Question 22

Evaluating the genetic explanation
-scientific

Answer 22

A strength of the genetic explanation is that it promotes psychology as a scientific discipline

This is because genetics can be studied objectively and reliably using DNA analysis and studying family history (concordance rates)

This would suggests that the genetic explanation of OCD promotes psychology as a scientific discipline

Question 23

Evaluating the genetic explanation
-biological reductionism

Answer 23

In addition, the genetic explanation may be biologically reductionist ….

This is because it ignores factors other than genes that may affect the development of OCD
Such as the role of early trauma in childhood (which has been repeatedly linked to OCD)

This implies, that although the genetic account of OCD is scientific, its an incomplete explanation of OCD