The Biological Approach To Explaining OCD: Genetic And Neural Flashcards
What is meant by the genetic explanation of OCD?
An explanation which suggests that a vulnerability towards developing ocd is inherited from parents and that ocd is polygenic meaning that there are lots of genes involved - ocd is not caused by a single gene.
What does the COMT gene do?
Catechol-o-methyltransferase
This gene regulates the production of dopamine.
How does the COMT gene affect OCD?
One variation of this gene results in higher levels of dopamine being produced and this is more common in patients with OCD.
What does the SERT gene do?
Serotonin transporter.
This gene affects the transport of the neurotransmitter serotonin.
How does the SERT gene affect OCD?
When transportation issues occur when this gene is transporting serotonin, this causes lower levels of serotonin to be active in the brain and is associated with OCD and depression.
What is meant by candidate genes?
Genes which increase a person’s vulnerability towards developing OCD - some of these genes are involved in regulating the development of the serotonin system.
What is meant by concordance rate?
The probability that a pair of individuals will have the same characteristic, given that one of the pair has the characteristic.
What do genetic explanations focus on when it comes to OCD?
These explanations focus on whether individuals inherit a genetic predisposition to developing OCD.
What is meant by the diathesis stress model?
This model suggests that genes only create a vulnerability towards developing a disorder. Other factors known as stressors affect what condition a person develops or whether they even develop an illness.
What do neural explanations focus on when it comes to OCD?
The role of neurotransmitters and certain areas of the brain.
How does serotonin affect OCD?
Serotonin regulates mood, low levels of this neurotransmitter results in mood disorders.
Piggot et al found that antidepressants that increase levels of serotonin in the brain, reduce symptoms of OCD.
How does dopamine affect OCD?
Higher levels of this neurotransmitter is associated with symptoms of OCD.
Describe how the brain circuit relates to OCD.
The orbital frontal cortex plays a significant role in emotions. This part of the brain sends messages of panic to the caudate nucleus and this gets passed onto the thalamus, if the message is seen as important, to take action.
PET scans have shown that there are higher levels of activity in the orbital frontal cortex of a person with OCD particularly when their symptoms are active.
What are two strengths of the biological approach to explaining OCD.
- Supporting evidence for genes.
Nestadt et al reviewed previous twin studies and found that 68 percent of identical twins shared OCD as opposed to 31 percent of non-identical twins.
Therefore, this strongly suggests a genetic influence on OCD.
- Led to development of successful drug treatments.
E.g soomro et al
What is one limitation of the biological approach to explaining OCD?
- There is an issue with understanding neural mechanisms involved in OCD.
research has identified other areas of the brain that are involved as well. This means that there is no brain system which has consistently been found to play a role in OCD.
Therefore, it cannot be concluded that there is a cause and effect relationship as it is difficult to determine whether biological abnormalities are a cause of OCD or, the result of OCD.
