Biological Approach to Explaining OCD Flashcards
biological approach to explaining OCD
2
genetic explanations
neural explanations
genetic explanations
3
mental disorders are inherited — individuals inherit specific genes from their parents that are related to OCD
gene = part of the chromosome that carries information in the form of DNA
this explanation includes…
• COMT gene
• SERT gene
• diathesis stress
define gene
1
a part of the chromosome that carries information in the form of DNA
genetic explanations: COMT gene
4
COMT gene may contribute to OCD
this gene is involved in the production of COMT, which regulates the production of the neurotransmitter dopamine that has been implicated in OCD
all genes come in different forms and one form of the COMT gene has been found to be more common in OCD patients than people without the disorder
this variation produces lower activity of the COMT gene and therefore high levels of dopamine, which is linked to OCD
genetic explanations: SERT gene
4
the SERT gene may also contribute to OCD
affects the transport of the neurotransmitter serotonin and creates lower levels of it
these low levels of serotonin are implicated in OCD
one study found a mutation of this gene in two unrelated families where 6 of 7 family members had OCD
genetic explanations: diathesis stress
3
individual genes create a vulnerability/diathesis for OCD as well as other mental disorders like depression
other factors affect what condition develops or whether any mental illness develops at all
therefore, some people could possess the COMT or SERT gene variations that make them more vulnerable to OCD but suffer no actual mental illness
neural explanations
2
genetic factors affect certain brain circuits
this explanation includes…
• abnormal levels of neurotransmitters
• abnormal brain circuits
neural explanations: abnormal levels of neurotransmitters
5
neurotransmitters = chemical substances that transmit nerve impulses across a synapse
dopamine is a neurotransmitter in the brain that effects motivation and drive — dopamine levels are thought to be abnormally high in people with OCD
animal research has found that high doses of drugs enhancing dopamine levels result in stereotypical movements resembling compulsive behaviours found in OCD patients
low levels of serotonin are also associated with OCD
antidepressant drugs that increase serotonin activity have been shown to reduce symptoms of OCD, whereas antidepressants that have less effect on serotonin do not reduce OCD symptoms
define neurotransmitter
2
chemical substances that transmit nerve impulses across a synapse
example = dopamine
define dopamine
2
a neurotransmitter in the brain that effects motivation and drive
dopamine levels are thought to be abnormally high in people with OCD
neural explanations: abnormal brain circuits
6
several areas of the frontal lobe are thought to be abnormal in people with OCD
caudate nucleus, located in the basal ganglia, normally suppresses signals from the orbitofrontal cortex (OFC), in turn the OFC sends signals to the thalamus about things that are worrying — such as a potential germ hazard
but when the caudate nucleus is damaged, it fails to suppress minor worry signals and the thalamus is alerted which then sends signals back to the OFC and a worry circuit is created
brain scans of OCD patients, taken while their symptoms are active (e.g. when someone with a germ obsession holds a dirty cloth), support this by showing heightened activity in the OFC
serotonin plays a key role in the operation of the OFC and the caudate nucleus, so abnormal levels of serotonin may cause these areas to malfunction
high levels of dopamine lead to overactivity in this region, also leading to OCD
x3 evaluation points for biological approach to explaining OCD
reductionist
support for genetic basis of OCD
real world applications
evaluation
REDUCTIONIST
4
a limitation of the approach is that it provides an overly simplistic and reductionist explanation of OCD
it suggests mental disorders like OCD are inherited via genes, but the idea of such a simple link between genes and OCD is unlikely
this can be seen to be reducing OCD, a complex disorder, to overly simplistic features which may be undermining it
by not considering other factors or the complexities of OCD, the approach may be providing an inaccurate explanation of OCD and may lead people to think that there are simply ways of treating OCD, which is not the case
evaluation
RESEARCH SUPPORT FOR THE GENETIC BASIS OF OCD
4
evidence for the genetic basis of OCD comes from family studies
one study identified 80 patients with OCD and 343 of their first degree relatives and compared them to 73 control patients without mental illness and 300 of their relatives
they found that people with a first degree relative with OCD had a five times greater risk of having the illness themselves at some point in their lives compared to the general population
supports the biological approach but suggesting that OCD is at least partly genetic
evaluation
REAL WORLD APPLICATIONS
6
the approach can been applied to real life
for example, it may be that where one parent has the COMT gene, the mother’s fertilised eggs can be screened, thus giving the parents the choice of whether to abort those eggs with the gene
such screening may also help parents prepare for the risk that their child may develop OCD and make them more aware of signs to look out for so treatment can be offered early
alternatively, gene therapy may produce a means of turning certain genes ‘off’ so that a disorder is not expressed
HOWEVER, both of these applications raise ethical issues
although this approach can also be applied to the treatment of OCD and has led to the development of such treatments (briefly describe…)
