Biolgical Explaintion To OCD

Question 1

Outline original obvserbation that supports genetic component

Answer 1

Lewis

1. Of his OCD patients, 40% parents and 20% has siblings with OVD
2. Suggests it runs in families

Question 2

Candidate genes

Answer 2

1. Genes identified to create vulnerability
2. Some of which involved in regulating development of serotonin system
3. Such as 5HT1-D which is involved in synaptic transmission of serotonin

Question 3

OCD is polygenic

Answer 3

1. Evidence suggests there may 230 genes involved

2. Some control dopamine others serotonin

Question 4

Different types of OCD

Answer 4

1. Genes that cause OCD in one person may differ to the next
2. Called aetiologically heterogenous
3. There are dif types of OCD so makes sense

Question 5

Neural explanations

Answer 5

Genes associated with OCD are likely to affect key neurotransmitters as well as brain structure

Question 6

Role of serotonin

Answer 6

1. Low levels of serotonin mean faulty transmissions of signals
2. OCD associated with reduced function of serotonin system

Question 7

Decision making systems

Answer 7

1. OCD associated with impaired decision making
2. In turn associated with the frontal lobes (logical thinking)
3. Parahippcampul gyrus associated with processing unpleasant emotions

Question 8

A03 for genetic explaitions

Answer 8

1. Good supporting evidence

2. Environmental risk factors

Question 9

There is good supporting evidence for genetic explanation

Answer 9

1. Evidence from twin studies
2. 70% of identical twins shared OCD
3. 30% of non-identical

Question 10

Environmental risk factors

Answer 10

1. Diathesis stress model
2. Study found 1/2 OCD patients had a traumatic event in their past
3. More server OCD= more than one trauma
4. Twin study, not 100% concordance
5. Cannot be entirely genetic

Question 11

Supporting evidence for neural explanations

Answer 11

1. Antidepressants that affect serotonin reduce symptoms of OCD, suggesting it’s involved

Question 12

Not clear what mechanisms involved

Answer 12

1. Found decision making systems are ones that function abnormally in OCD
2. Other brain systems identified but not consistent findings
3. Unable to claim complete understanding

Question 13

Correlate rather than cause

Answer 13

Brian systems may be faulty because of third factor that causes both OCD and faulty brain

Question 14

Serotonin-OCD link may just be co-morbidity

Answer 14

1. People with OCD become depressed (two conditions is co-morbidity)
2. Serotonin might be the depression not the OCD