psychopathology- biological approach to explaining and treating ocd Flashcards
ao1 done for both, ao3 for treating done
what are the 2 genetic explanations
COMT gene
SERT gene
diathesis stress
the genetic explanations focus on the meaning that individuals inherit ….
specific genes from their parents that are related to the onset of OCD
view that mental disorders/behaviour is determined and therefore explained through someones biology / genes
what is the comt gene explanation
it is involved in the productions of COMT which regulates the production of the neurotransmitter dopamine which is implicated in ocd.
one allele of the comt gene has been found to be more common in ocd patients that without people without.
this variation produces LOWER activity of the comt gene and so there are higher levels of dopamine
what is the SERT gene explanation
this gene affects the transport of serotonin > it creates lower levels of it
low levels of S are implicated in ocd.
one study found a mutation of this gene in two unrelated families where six of the seven family members had ocd
what is the diathesis stress explanation
a model that suggests that the presence of a specific gene allele/mutation only creates a vulnerability (diathesis) for ocd (as well as other conditions eg depression)
and that the condition only presents itself when prompted to by a stressor eg trauma
and so people might possess the comt/sert gene variations but have no symptoms because the condition hasnt been manifested
what are the 2 neural explanations
abnormal levels of neurotransmitters
abnormal brain circuits
what is the abnormal levels of neurotransmitters explanation (dopamine bit)
thought that abnormally high D levels in those with ocd.
this is based on animal studies where high doses of drugs that enhance D levels were injected and this induced stereotyped movements resembling the compulsive behaviours found in ocd patients
what is the abnormal levels of neurotransmitters explanation (serotonin bit)
lower levels of S are associated with ocd.
based on fact that antidepressant drugs that increase S activity have been shown to reduce ocd symptoms VS antidepressants that have less effect on S do not reduce ocd symptoms
what is the abnormal brain circuits explanation
(what are the parts, what is the worry circuit, how is it explained in pet scans)
several areas in the frontal lobe are abnormal in people with ocd
eg caudate nucleus
so orbitofrontal cortex DOES send signals to the thalamus about things that are worrying eg potential germ hazard
so when caudate nucleus is damages it fails to suppress minor “worry” signals and so thalamus IS alerted
this then sends signals back to ofc in a worry circuit
pet scan when ocd symptoms are active > shows more activity in ofc
active eg when a germ obsessive holds a dirty cloth
which neurotransmitter is associated with comt gene and the sert gene
comt- dopamine
sert-serotonin
what is the abnormal levels of dopamine explanation based on
animal studies
what is the abnormal levels of serotonin explanation based on
antidepressants
what does the caudate nucleus normally do
suppress signals from the orbitofrontal cortex (OFC)
what is involved in the worry circuit
orbitofrontal cortex (ofc) and thalamus
what is the abnormal brain circuits explanation based on
pet scans
what neurotransmitters are associated with the brain regions that are abnormal
serotonin > abnormal > caudate nucleus and ofc malfunction
dopamine for basal ganglia (containing caudate nucleus) abnormal levels > malfunction
evaluation for explanation: a strength is the real world application (genome….. and gene ……)
cp also implies that…
rwa- genome mapping can link genes to specific disorders
done by screening fertilised eggs > give mother option to abort if they are predisposed to disorder (ocd)
AND: gene therapy can “turn off” certain genes so that the disorder does not present.
HOWEVER there are ethical issues with both > controversial
ALSO implies that the link between genes and disorders like ocd is simple when its not.
evaluation for explanation: research support from family and twin studies (2 examples)
nestad family studies show a link between genetics and ocd
80 ocd patients and 343 1stdeg relatives and compared to 73 controls without mental illness and 300 of their relatives and FOUND people with a 1st degrel with ocd had a 5x greater risk of having ocd compared to controls
a meta analysis
what is the biological approach to treating ocd
drug therapy
what are the types of drug therapy for treating ocd
antidepressants (SSRIs and tricyclics)
antianxiety drugs
there are also some other drugs (antibiotic d-cycloserine)
what does SSRI stand for
selective serotonin reuptake inhibitors