The Biological Approach to Explaining OCD

Question 1

What is a candidate gene?

Answer 1

Specific genes which create a vulnerability for a mental disorder

Question 2

What are two types of genes shown to be a candidate gene to OCD?

Answer 2

• Serotonin genes

- Dopamine genes

Question 3

What are serotonin genes?

Answer 3

Implanted in the transmission of serotonin across synapses

Question 4

What is an example of a serotonin gene?

Answer 4

5HT1-D beta

Question 5

What does serotonin and dopamine regulate?

Answer 5

Mood

Question 6

What does it mean by calling OCD polygenic?

Answer 6

OCD is not caused by one single gene but several genes involved

Question 7

What did Taylor (2013) find about OCD and being polygenic?

Answer 7

The are 230 different genes that may be involved in OCD

Question 8

What does the COMT gene do?

Answer 8

Helps reduce the action of dopamine

Question 9

What does the SERT gene do?

Answer 9

Affects the transport of serotonin

Question 10

What does the diathesis-stress model suggest about OCD?

Answer 10

People gain a vulnerability towards OCD through genes but an environmental stressor is also required

Question 11

What is aetiologically heterogeneous?

Answer 11

One group of genes may cause OCD in one person but in a different person it may be caused a different group of genes

Question 12

Are levels of serotonin higher or lower in those suffering from OCD?

Answer 12

Lower

Question 13

Are levels of dopamine higher or lower in those suffering from OCD?

Answer 13

Higher

Question 14

What is dysfunctional about people with OCD?

Answer 14

• Frontal lobe

- Parahippocampal gyrus

Question 15

What is the frontal lobe responsible for?

Answer 15

Logical thinking and making decisions

Question 16

What is the left parahippocampal gyrus responsible for?

Answer 16

Processing unpleasant emotions

Question 17

Is there supporting evidence the genetic explanation?

Answer 17

Yes

Question 18

What is a good study to show the effect of genes?

Answer 18

Twin studies

Question 19

What did Nestadt et al (2010) find?

Answer 19

68% of identical twin shared OCD opposed to the 31% of non-identical twins

Question 20

What is the limitations of twins studies?

Answer 20

• Environment may have actually caused disorder
• Observing and imitating the behaviour
• Difficult to untangle effects of environment and genetics factors

Question 21

What is the problem with candidate genes?

Answer 21

• Too many genes involved
• Not successful at pinning down all the genes involved
• Genetic variation only increases the risk of OCD by a fraction

Question 22

What did Cromer et al (2007) find?

Answer 22

Over half of their sample had a traumatic event in the past and had a more sever OCD

Question 23

Why is the neural explanation good for practical application?

Answer 23

Allows medication to be developed which helps sufferers

Question 24

Why may the serotonin-OCD link not be as unique as believed?

Answer 24

Those with OCD become depressed (co-morbidity)