Biological approach Towards Explaining OCD

Question 1

Behavioural explanations to OCD

Answer 1

REPETETIVE COMPULSIONS
-these compulsions are completed in order to reduce anxiety caused by obsessions eg obsession with germs- repetitive handwashing.
AVOIDANCE
-attempting to reduce anxiety by staying away from situations that trigger anxiety.

Question 2

Cognitive explanations of OCD

Answer 2

obsessive thoughts
cognitive coping strategies- eg a religious person may pray to relive anxiety or guilt.
people with ocd are aware that their obsessions are irrational
tend to be hypervigilant

Question 3

Emotional characteristics

Answer 3

anxiety and distress- the urge to repeat a compulsion causes distress

Question 4

Genetic explanations

Answer 4

Genes are involved in individual vulnerability
- Lewis observed ocd patients 37% had parents with ocd and 21% had siblings with ocd.
— this suggests that ocd runs in families
- according to the diathesis stress model certain genes leaves some people more likely to develop a mental disorder but not certain. An environmental trigger is needed to trigger the condition.

• researcher Taylor identified that around 230 candidate genes are involved in vulnerability of developing ocd meaning that is caused by a combination of genes (polygenic)
  COMT GENE- associated with dopamine
  SERT GENE- associated with serotonin
  OCD is aetiologically heterogeneous meaning that the origin of ocd can vary from one person to another.

Question 5

Neural explanations

Answer 5

Serotonin is a neurotransmitter believed to help regulate mood.
Responsible for transferring information from one neurone to another. If a person has low levels of serotonin then their moods may be low suggesting that some cases of ocd may be explained by a reduction in the functioning in the serotonin system in the brain.
Some cases of OCD in particular hoarding seem to be associated with decision making systems which may be associated with abnormal functioning lateral frontal lobes
There is evidence to suggest that the parahippocampal gyrus associated with processing unpleasant emotions functions abnormally in OCD.

Question 6

Evaluation positives

Answer 6

+ strong evidence base- twin studies Nestadt found that 67% of identical twins MZ shared OCD as opposed to 31% of non identical DZ twins.
Family studies Marini found that those with a family member with OCD are four times more likely to develop the disorder.

+ applications antidepressants that work purely on serotonin are effective in reducing symptoms of OCD.

Question 7

Evaluation negatives

Answer 7

• environmental risk factors
  Found to be triggered by more environmental factors
  Cromer found that over half the OCD clients had experienced a traumatic event in their past meaning that genetic vulnerability is only a partial explanation for developing OCD.
• use of animal studies difficult to generalise to behaviour of humans
• neural model the serotonin OCD link may not be unique to OCD
  Many people with ocd also experience clinical depression which is known as co morbidity meaning tat the involvement of serotonin may be due to the depression.
• despite the evidence brain dysfunction may simply be a correlation to ocd.

Question 8

Abnormal brain circuits

Answer 8

The orbifrontal context sends signals to the thalamus about worrying things when the caudate nucleus is damaged it falls to suppress any minor worry signals starting a worry circuit
This is supported by PET scanning - when symptoms are active the scan shows heightened activity in the OFC.