Psychopathology - bio explanations of OCD

Question 1

What is OCD?

Answer 1

An anxiety disorder where an anxiety arises from obsessions and compulsions.

Question 2

What are the behavioural characteristics of OCD?

Answer 2

• Repetitive compulsions
• Compulsions to avoid anxiety
• Avoidance

Question 3

What are the emotional characteristics of OCD?

Answer 3

• Anxiety and distress
• Accompanying depression
• Guilt and disgust

Question 4

What are the cognitive characteristics of OCD?

Answer 4

• Obsessive thoughts
• Cog. coping strategies
• Excessive anxiety

Question 5

What does the bio appr. suggest about genes in OCD?

Answer 5

OCD can be largely understood as biological. Genes can make someone prone to the disorder.

Question 6

What did Lewis find w/ his patients in terms of genes?

Answer 6

37% of parents of his patients also had OCD while 21% of siblings of his ps also had OCD - suggests genetic disposition.

Question 7

What did Nestadt er al. find about genes in OCD using twin studies?

Answer 7

68% of monozygotic twins shared OCD while 31% of dizygotic twins shared OCD.

Question 8

What does the diathesis stress say about genes in OCD?

Answer 8

Genes don’t make OCD certain but the genetic vulnerability is passed on and can then be triggered by certain experiences.

Question 9

What are candidate genes?

Answer 9

Responsible for vulnerability to OCD. They have been identified as being responsible for vulnerability. Some of these genes regulate the serotonin system such as 5HT1-D beta which transport serotonin across the synapse.
OCD is polygenic - not caused by one gene but there are several involved.
Diff. genes could cause OCD is diff. ppl.

Question 10

What do we call OCD because it has diff. genes w/ diff. causes?

Answer 10

Aetiologically heterogeneous.

Question 11

What do neural explanations of OCD focus on?

Answer 11

Focuses on neurotransmitters as well as brain structures.

Question 12

Which neurotransmitter can explain some cases of OCD?

Answer 12

Serotonin is a NT believed to regulate mood. Some OCD can be explained by a reduction in the functioning of the serotonin system.
Someone w/ low serotonin levels may not have normal transmission of mood relevant info meaning other functions may be affected.

Question 13

How could abnormal functioning in the frontal lobes cause OCD?

Answer 13

Abnormal functioning in lateral of frontal lobes can lead to OCD.
The frontal lobes are responsible for logical thinking and decision making.

Question 14

What area of the brain other than the serotonin system and the frontal lobes could cause OCD?

Answer 14

The parahippocampal gyrus functions abnormally in OCD. It is associated w/ processing unpleasant emotions.

Question 15

Genetic explanations AO3: What supporting evidence is there?

Answer 15

Nestadt et al. (2010) reviewed twin studies. Found that 68% of monozygotic twins shared OCD compared to 37% of dizygotic twins which suggests a strong genetic link.

Question 16

Genetic explanations AO3: Why are these unlikely to ever be useful?

Answer 16

It provides little value in predicting if someone might get OCD. Psychologists have been unsuccessful at working out all of the genes involved. There are several genes are involved and each genetic variation increases the risk by a fraction.

Question 17

Neural explanations AO3: What supporting evidence is there?

Answer 17

Antidepressants work only on the serotonin system and can be used effectively to reduce OCD symptoms. Antidepressants increase the amount of the neurotransmitter being produced. Suggests serotonin system is involved in OCD.
OCD symptoms also from part of other conditions which have biological origin e.g. Parkinson’s disease.

Question 18

Neural explanations AO3: What is a weakness of this study?

Answer 18

There is no one neural system identified for causing OCD. There is evidence that neurotransmitters and brain structure do not function abnormally in OCD. Biological abnormalities could be caused OCD rather than be the cause of it.