Psychopathology: Biological approach to explaining OCD

Question 1

How is OCD characterised??

Answer 1

By obsessions (recurring thoughts) and compulsions (repetitive behaviours)

Question 2

What are 2 emotional characteristics of OCD??

Answer 2

Distress and depression

Question 3

What is the model that is part of the genetic explanation for OCD??

Answer 3

Diathesis-stress model -> Certain genes mean some people are more likely to have OCD, but an environmental stressor is needed to trigger it

Question 4

What are candidate genes??

Answer 4

A gene that makes it more likely to develop OCD

Question 5

What is an example of a candidate gene??

Answer 5

5HT1-D beta

It control serotonin levels in the brain

Question 6

What are the 2 supporting AO1 studies for the genetic explanations of OCD??

Answer 6

Lewis (1936) -> 37% of OCD patients had parents with OCD and 21% had siblings with OCD.

Taylor (2013) -> Analysed findings of previous studies and found that up to 230 different genes may be involved in OCD

Question 6

What are the 3 evaluation points for the genetic explanations of OCD??

Answer 6

• Nestadt et al (2010)
• Too many candidate genes
• Cromer et al (2007)

Question 7

What did Nestadt et al (2010) do??

Answer 7

Analysed findings of previous studies and found that:
- 60% of identical twins shared OCD
- 31% of non-identical twins shared OCD

Proves it can be genetic

Question 8

Why is ‘too many candidate genes’ a weakness for the genetic explanations of OCD??

Answer 8

Psychologists have been less successful at pinning all the genes involved.. This is because there are so many candidate genes and each variation only increases the risk of OCD by a fraction.

Question 9

What did Cromer et al (2007) find??

Answer 9

Over 50% of OCD patients (in their sample) had trauma and OCD was more severe when there was more than one trauma.

Question 10

What is the neural explanation of OCD?? (serotonin)

Answer 10

Serotonin levels impair the connection between:
- Orbitofrontal cortex (becomes overactive leading to excessive obsessions)
- Basal ganglia (Gets stuck in repetitive loops, causing compulsions)

Question 11

What is the neural explanation of OCD?? (Decision-making systems)

Answer 11

Some cases of OCD (e.g. hoarding disorder) may be associated with abnormal functioning of the frontal lobe in the brain.

Left parahippocampal gyrus = associated with processing unpleasant emotions. It functions abnormally in OCD.

Question 12

What is the evaluation point for the neural explanations of OCD??

Answer 12

Some antidepressants target serotonin specifically and will increase serotonin levels. These drugs often decrease OCD symptoms which supports that OCD is related to serotonin levels