Biological Approach To Explaining OCD Flashcards
What is meant by ‘genetic explanations’?
An explanation for mental disorders such as OCD that says they may be inherited
Mean that an individual inherits a specific gene from their parents that relates to the onset of OCD
What is the implication of the COMT gene?
Involved in the regulation of the neurotransmitter dopamine
Increased dopamine has been implicated in OCD
An allele of the COMT gene has been found commonly in patients with OCD and produces lower activity of the COMT gene and higher levels of dopamine
Implication of the SERT gene
The SERT gene affects the transport of serotonin, creating lower levels of the neurotransmitter
Lower serotonin is implicated in OCD
What does the diathesis- stress model outline?
Explains that individuals may have a genetic disposition for OCD
There is an interaction between genes and the environment
Gene provides predisposition to developing OCD but would need to be triggered environmentally
How has dopamine and serotonin been implicated in OCD, research evidence ?
If increased in animals, display stereotypical movements that resemble compulsive behaviours found in OCD patients
How has serotonin been implicated in OCD (research evidence)?
SSRI’s (anti depressant that increases levels of serotonin) relieve symptoms of OCD in many cases
PET scans have shown low levels of serotonin activity in the brains of OCD patients
How have abnormal brain circuits been implicated in OCD?
Increase in thalamic activity results in over active orbitofrontal cortex to create ‘worry circuit’
Research evidence supporting the implication of abnormal brain circuits
PET scans have shown over active OFC
Serotonin levels might affect the areas
Dopamine also implicated
Hu (2006)
Evidence for the role of serotonin in OCD- serotonin levels much lower in OCD patients compared to regular
Positives of the biological approach to explaining OCD
Meta analysis of Grootherst et Al (2005) found there was a 45-65% concordance rate of OCD in MZ twins
Hu (2006) found that serotonin levels were much lower in those with OCD
Negatives of the biological approach to explaining OCD
Issue of cause and effect
Use of antidepressants in treating OCD
Most commonly used drugs in treatment
Work to increase availability of serotonin in the brain
How do SSRI’s work?
Work to increase the level of serotonin in order to normalise the activity of the ‘worry circuit’
SSRI’s work by preventing the reabsorbtion of serotonin by the presynaptic neurone so there are greater levels of available serotonin
Use of anti anxiety drugs to treat OCD
Benzodiazepines, commonly used to reduce anxiety and slow the activity of the CNS by enhancing the activity of the GABA neurotransmitter
Explain the role of GABA
Has a quietening effect on the brain by reacting with special sites on the receiving neurones to increase the of chloride ions into the brain- makes it more difficult for neurone to be stimulated by other neurotransmitters
