explanation for OCD Flashcards
(21 cards)
what is the explanation for ocd
the biological approach
the two parts the biological explanation is broken into
- the genetic explanation for ocd
-Neural explanation relating to the nervous system (neutransmitter levels and an abnormal brain circut)
describe the genetic explanation for ocd
- this is the idea that ocd that a person is more likely to have ocd if a family member has it this is because of the genetics they have inherited from their parents. These genetics give the individuals predisposition (vulnerability) to ocdf
what genes are involved in ocd
COMT and SERT genes
(mutations in the genes)
evidence for the role of the COMT gene
Tukel et (2013)
compared 100 individuals and 101 individuals with ocd and he found that there was a lower activity in the group which had ocd
this lead to higher levels of dopamine
evidence for the role of the SERT gene
Ozaki et (2013)
found a mutation of the geneintwo different families and he found that 6/7 family members had OCD
this gene is the associated with low levels of serotonin (comorbility depression)
what are concordance rates ?
the degree of genetic similarity for a particular trait
what types of studies for the role of genetics for ocd be seen in
- twin studies
supporting evidence for the genetic explanation of ocd
- Nesdat et al (2010)
in their review of OCD and genetics they found of all the twin study research published till date that monzygotic twins had a higher concordance rate for ocd that dizygotic twins
if ocd is genetic there should be a higher concordance rate for monzygotic twins that dizygotic twins which is waht Nesdat et al found - they found a 68% concordance rate in monozygotic twins and whereas dizygotic twins had a 31% concordance rate
the neurotransmitter lelvels explanation (d) + supporting evidence
- higher levels of dopamine are associated with complusive behaviours for ocd
Kim et al (2007)
gave OCD patients drugs that affected their dopamine levels
(decreased dopamine levels)
this was correlated with lower levels of compulsions
these findings suggest that the dopamine neurotransmitter system can play an important role in ocd patients
the neurotransmitter lelvels explanation (s) supporting evidence
low levels of the neurotransmitter serotonin has been associated with PET scans show relatively low levels of serotonin activity in the brains of OCD patients as as drugs that increase serotonin activity have been found to reduce the symptoms of OCD. The scans also show that OCD sufferers have relatively high levels of activity in the orbital frontal cortex
what is the neural explanation for ocd
- abnormal brain circuit (the worry circuit)
orbito front cortex
basal ganglia (cau
thalmus
what does is orbitiofrontal cortex cfunction?
the function of the orbitofrontal cortex is involved with our perception of the word, loigical thinking and desicion making and when we are worried this signal is sent to to the thalmus
what is the function of the thalamus?
- the thalamus is thought to be centre of the perception of pain
what structure filters or supresses the worry signal from the orbito frontal cortex to the thalamus?
- basal ganglia
(caudate nuclues)
what happens when there is a problem with the basal ganglia?
- if there is something abnormal, the thalamus gets alerted to the signal quite strongly and confirms this worry back to the orbitofrontal cortex which is invoilved with the perception pain, decison making and logical thinking which then starts to obsess about this worry - this is then suggested that this worry circuit is over active which leads to complusive behaviours to cope with the obsessive thoughts and anxiety
evidence of the role of the worry circuit
Beucke et al (2013)
They investigated patients that were on medication and OCD patients that were not medication
They found that patients that were not on medication showed greater activity in the orbitofrontal cortex
The level of the activity of the orbiitofrontal cortex was further correlated with the severity of the OCD symptoms
evalutations for the biologival explanations of ocd
positive
practical application
[drug treatments]
if one of they key factors involved in OCD is the level of a specific neurotransmitter , medication to increase (serotonin) of decrease the level of the neurotransmitter can be prescribed to help the patients symptoms and the imbalance (SSRI’s) this illustrates the value that the biological explanation has in helping to improve the lives of individuals that suffer with ocd
What is an alternative explanation for OCD
The diathesis -stress model
What does the diathesis stress model propose
It proposes an explanation on how biological and environmental factors can be inconnected.
It suggests that the role of genetics acts as a predisposition or vulnerability for OCD
but..
OCD may never develop if there is not a stressor (an environmental trigger)
Cromer at (2007) found that 50% of patients in his sample had a traumatic event in their pass
This suggests that the biological explanation alone is sufficient to fully explain OCD and that the diathesis - stress model helpfully offers an explanation for how biology and the environment can both be involved
What issue and debate can we use?
- Deterministic
this biological explanation states that OCD is determined or caused by internal biological factors eg genes, neurotransmitters or neural factors. As a result people who suffer from OCD have no control or freewill over their behaviour and are unable to change
This is a very pessimestic view as it suggests that the individual are not able to change or improve. Their obessesive thoughts and complusive behaviours are therefore deemed as inenvitable. Perhaps, taking a deterministic view may ADD to the anxiety of the individual that those suffering are already experiencing OCD
Therefore the biological explanation can be seen as limited in its view of OCD because of the lack of choice it sees people have to manage it
