Biological Approach To Explaining OCD

Question 1

Define polygenic

Answer 1

OCD is caused by several genes

Question 2

Describe the genetic explanation of OCD

Answer 2

• focused on candidate genes
• it is believed that OCD is a polygenic which means several genes are involved
  COMT and SERT gene is linked to OCD
  COMT gene produces COMT which regulates neurotransmitter dopamine- COMT gene results in higher levels of dopamine
  SERT gene is linked to serotonin and affects the transport of the neurotransmitter- causes low lvls of serotonin to brain and are associated with OCD

Question 3

Describe neural explanations for OCD

Answer 3

Serotonin regulates mood and low levels of serotonin is associated with mood disorders
OCD is associated with reduced levels of serotonin which may be caused by the SERT gene
It has been found that serotonin in OCD come from research examining antidepressants (SSRI) who found that drugs increase the level of serotonin in the synaptic gap are effective in treating patients with OCD
Dopamine also implicated in OCD- higher levels of dopamine lead to compulsive behaviour

Question 4

Describe neural explanations for OCD in terms of brain structure

Answer 4

Basal ganglia and orbitofrontal cortex are associated with OCD
Basal ganglia- cluster of neurons at the base of the forebrain- involves the coordination of movement- damage in this area leads to OCD symptoms
Orbitofrontal cortex- converts sensory info to thoughts and actions- leads to compulsions

Question 5

AO3

Answer 5

+ research support nestadt et al
- genetics play a part- a close relative who has OCD there is a five more times likely chance to develop disorder
+ twin studies
- Billett et al- meta analysis on 14 twin studies investigating the genetic inheritance on OCD- MZ twins has the double chance of getting OCD compared to DZ if one pair had the disorder
—too many candidate genes
- 230 candidate genes coding for increased risk of OCD- practical issue - difficult to pinpoint which has the greatest influence so which genes drugs treatment would target
— ignores environmental influences
- found that over half of OCD patients have suffered from trauma in the lives- positive correlation- increasing traumas lead to OCD