Psychopathology: The Biolgocial Approach To Exlaining OCD Flashcards
Outline the genetic explanation to explaining OCD
- genes are involved in individual vulnerability to OCD
- Lewis observed, of his OCD patients, 37% had patients with OCD and 21% had siblings with OCD
- this suggests OCD runs in families but that genetic vulnerability is likely passed on and not certainty of OCD
The diathesis tress model states certain genes leave some people more likely to suffer a mental disorder
What are candidate genes
- researchers have identified genes which create vulnerability for OCD (candidate genes)
- some of these genes are involved in regulating the development of the serotonin system
- e.g. the 5HT1-D beta is used in the transport of serotonin across synapses
Outline ‘OCD is polygenic’ as a possible genetic explanation for OCD
- OCD is polygenic, meaning it is not caused by one single gene but rather several genes
- Taylor - analysed findings of previous studies and found up to 230 different genes may be involved in OCD
- dopamine and serotonin (which are believed to have a role in regulating mood) are also thought to be involved in OCD
What does aetiologically heterogenous mean
- OCD is aetiologically heterogenous
- meaning the origin of OCD has different causes
- there is some evidence to suggest that different types of ocd may be the result of particular genetic variations. E.g. hoarding disorder and religious obsession
Outline the neural explanation for OCD
- genes associated with OCD are likely to affect the levels of key neurotransmitters as well as structures of the brain
Outline the role of serotonin as a neural explanation for OCD
- serotonin is believed to help regulate mood
- neurotransmitters are responsible for relating information form one neuron to another
- if an individual has low levels of serotonin then normal transmission of mood relevant info does not take place so mood can be significantly affected
Outline the role of decision making systems as a neural explanation for OCD
- some cases of ocd (in particular hoarding disorder) are associated with impaired decision making
- in turn, this may be associated with abnormal functioning of the lateral of the frontal lobes of the Brain
- the frontal lobes are responsible for decision making + logical thinking
What are the three evaluation points for genetic explanations to explaining OCD
- good supporting evidence
- too many candidate genes
- environmental risk factors
Outline ‘good supporting evidence ‘ as an evaluation point for genetic explanations for OCD
- research evidence to suggest that some people are vulnerable to OCD as a result of their genetic make up
- twin studies provides the best evidence for this
- Nestadt et al - reviewed previous twin studies and found 68% of identical twins shared OCD as opposed to 31% of non identical twins
Outline ‘too many candidate genes ‘ as an evaluation point for genetic explanations for OCD
- psychologists have been fairly unsuccessful at pinning down the exact genes involved
- this is because it appear several genes are involved and that each genetic radiation only increases the changes of getting OCD by a fraction
Outline ‘environmental risk factors ‘ as an evaluation point for genetic explanations for OCD
- environmental risk factors can also trigger or increase the risk of developing OCD
- Cromer et al - found over half the OCD patients in their sample had a traumatic event in their past and OCD was more severe for those who had experienced trauma
What are the three evaluation points for neural explanations for OCD
- some supporting evidence
- not exactly clear what neural mechanisms are involved
- we can’t assume neural mechanisms cause OCD
Outline ‘some supporting evidence‘ as an evaluation point for neural explanations for OCD
- evidence to support the role of some neural mechanisms in OCD
- e.g. some antidepressants work purely on the serotonin system, increasing levels of the neurotransmitter
- these drugs are effective at reducing OCD symptoms which suggests serotonin system is involved
Outline ‘not exactly clear what neural mechanisms are involved ‘ as an evaluation point for neural explanations for OCD
- studies of decision making have shown that these neural systems are the same systems that function abnormally in OCD (cavedini)
- however, research has also identified other brain systems that may be involved sometimes
Outline ‘we can’t assume neural mechanisms cause OCD‘ as an evaluation point for neural explanations for OCD
- there is evidence to suggest various neurotransmitters and structures in the brain don’t function normally in patients with OCD
- however, this is not the same as saying this abnormal functioning CAUSES the ocd, instead, they may come as a result of the OCD
