The biological approach to explaining OCD Flashcards
describe the biological approach
a perspective that emphasises the importance of physical processes in the body such as genetic inheritance and neural function
describe genetic explanations
genes are involved in individual vulnerability to OCD
lewis (1936) observed that of his OCD patients, 37% had parents with OCD and 21% had siblings with OCD
this suggests that OCD runs in families, what is passed down is the vulnerability
some environmental stress is necessary to trigger the condition
describe candidate genes
some of the candidate genes for OCD are involved in regulating the development of the serotonin system
e.g., 5HT1-D beta is implicated in the transport of serotonin across synapses
describe how OCD is polygenic
OCD is not caused by one single gene but a combination of genetic variations that together significantly increase vulnerability
taylor (2013) found evidence that up to 230 different genes may be involved in OCD
a lot of these genes include those associated with the action of the neurotransmitters serotonin and dopamine
explain the different types of OCD
one group of genes may cause OCD in one person but a different group of genes may cause the disorder in another - aetiologically heterogeneous
different types of OCD may be the result of particular genetic variations
describe neural explanations
the view that physical and psychological characteristics are determined by the behaviour of the nervous system
the genes associated with OCD are likely to affect the levels of key neurotransmitters
describe the role of serotonin
serotonin is believed the help regulate mood
if a person has low levels of serotonin then normal transmission of mood-relevant info does not take place and a person may experience low moods
some cases of OCD can be explained by a reduction in the functioning of the serotonin system in the brain
describe decision-making systems
some cases of OCD seem to be associated with impaired decision-making, this in turn may be associated with abnormal functioning of the lateral of the frontal lobes, the part of the brain responsible for logical thinking and making decisions
evidence to suggest that the left parahippocampal gyrus, associated with processing unpleasant emotions, functions abnormally in OCD
what is the research support for the genetic explanation of OCD (STRENGTH)
evidence from a variety of sources to suggest some people are vulnerable to OCD as a result of their genetic make-up
twin studies - 68% of MZ twins shared OCD as opposed to 31% of DZ twins
a person with a family member diagnosed with OCD is around 4x as likely to develop it
therefore, research studies suggest that there must be some genetic influence in OCD
why are environmental risk factors important (LIMITATION)
it seems that environmental risk factors can also trigger or increase the risk of developing OCD
cromer et al. (2007) found that over half the OCD clients in their sample experienced a traumatic event in their past, OCD was more severe in those with one or more traumas
therefore, genetic vulnerability only provides a partial explanation
what is the research support for the neural model of OCD (STRENGTH)
antidepressants that work purely on serotonin are effective in reducing OCD symptoms, suggesting serotonin is involved in OCD
OCD symptoms also form parts of conditions that are known to be biological in origin
therefore, biological factors may be responsible for OCD
why might the serotonin-OCD link not be unique to OCD (LIMITATION)
many people with OCD also experience clinical depression, this is co-morbidity
the depression may involve disruption to the action of serotonin
it may simply be that serotonin activity is disrupted in many people with OCD because they are depressed as well
therefore, serotonin may not be relevant to OCD symptoms
