psychopathology 1.5 Flashcards
The biological approach to explaining and treating OCD: genetic and neural explanations; drug therapy.
what is the biological approach known as?
medical model as it explains all behaviour through our biology
how does biological approach explain OCD?
abnormal biological processes
genetic explanations
hereditary influences transmitted from parent to offspring by genetic transmission
polygenic
this means OCD is not caused by one single gene but by a combination of genetic variations that together cause significantly increased vulnerability
candidate genes
genes that create vulnerability to OCD
what did Taylor (2013) find?
evidence from previous studies that there are up to 230 different genes which may be involved with OCD
(there are different types of genes that cause OCD and one gene variation or group of genes may cause it in one person, but another sufferer of OCD could have a different variation of genes)
which genes have been studied in relation to OCD?
dopamine and serotonin
roles of dopamine and serotonin
a role in regulating mood
what did Tukel et al (2013) suggest?
a variation of the COMT gene may contribute to OCD as it is more common in patients who suffer from OCD than in those that do not
this variation produces higher levels of dopamine and lower activity of the COMT gene
how has the 5-HTT gene been linked with OCD?
it affects the levels of serotonin, making them less and these lower levels of the neurotransmitter are linked with OCD
strengths of genetic explanations of OCD
a strong evidence base of research, especially within twin studies.
Nestadt et al. (2010) reviewed evidence that 68% of identical twins will both have OCD compared to 31% of non-identical twins. Marini et al (2012) found a person with a family member diagnosed with OCD is around 4 times as likely to develop it as someone without
This is a significant link to show that genetics play an important role in the development of OCD and that nature (in the nature/nurture debate) is shown to play a large role here
Grootheest et al. (2005) found their genetic link was stronger in children that were sufferers of OCD
limitations of genetic explanations of OCD
ignores environmental factors, although twin studies are used as there is a greater genetic link, these twins also share the same environment, which could trigger OCD
there is evidence to suggest that identical twins are treated ‘more similar’ in terms of their environment, (e.g. expectations, style of dress, extracurricular activities) than non-identical twins who are treated more as individuals
Pato et al. (2001) noted that although there does seem to be a genetic link between OCD sufferers, there is not enough understanding about the actual genetic mechanisms causing OCD
Grootheest et al. (2005) found that the genetic link was stronger in children that were sufferers of OCD, than when the OCD originated in adulthood, showing the probability of different causes
neural explanations of OCD
OCD can also be explained through neural connections and the imbalance or damage these can have
the explanation links to the genetic difference that has been found in OCD sufferers, where the gene, influences the levels of key neurotransmitters and the structures in the brain.
what might have caused the neural damage?
may have been caused by illnesses that affect the immune system, such as different bacterias
serotonin
known to play a role in regulating mood
what happens if a person has low levels of serotonin?
the person can have low moods and other mental processes are often affected
reduction of serotonin can explain some cases of OCD
in people with OCD, what are their dopamine levels like?
abnormally high
the orbital Frontal Cortex (OFC)
sends signals to the thalamus about things that are worrying you
this area of the brain is overactive in people who suffer from OCD
the thalamus
the part of the brain that instructs the person to do a certain activity or behaviour
in OCD sufferers, this would be the OCD behaviour
the caudate nucleus
the part of the brain that in non-OCD suffers, surprises the messages from the OFC, and normalises the worry, however, in OCD suffers, this part of the brain is not completing this job and allows the OFC to make the sufferer worry
this could be due to damage or overstimulation
what have some forms of OCD been linked with?
poor decision making
what causes poor decision making?
which could be down to abnormal functioning in the lateral parts of the frontal lobes. (the parts of the brain responsible for logical thinking and making decisions)
strengths of neural explanations for OCD
antidepressants such as SSRIs, which are used to control levels of serotonin, are seen to be effective in reducing OCD symptoms, which would support the idea of an imbalanced neural network
limitations of neural explanations of OCD
there is evidence that environmental triggers can play a large role in triggering OCD, one study found over half the participants had suffered a traumatic event, and this led to their OCD.
not all OCD sufferers respond positively to antidepressants ( serotonin levelers), which would show it is not the neural network causing OCD in those patients.
what does drug therapy for mental disorders aim to do?
increase or decrease levels of neurotransmitters in the brain or to increase/decrease their activity
low levels of serotonin associated with OCD
therefore, drugs work in various ways to increase level of serotonin in the brain
what do selective serotonin reuptake inhibitors (SSRIs) do?
prevent reabsorption and breakdown of serotonin in the brain
this increases its levels in the synapse and thus serotonin continues to stimulate the post synaptic neuron
this compensates for whatever is wrong with serotonin system in OCD
what speed does reuptake happen in people with OCD?
too fast
typical dosages
typical daily dose of fluoxetine (an SSRI) is 20mg
this may be increased if not benefitting person
how long does it take for daily use of drug therapy to work?
3-4 months
combining SSRIs with CBT
the drugs reduce a person’s emotional symptoms such as feeling anxious or depressed
this means they can engage more effectively with CBT
describe SNRIs
serotonin noradrenaline reuptake inhibitors
work in a similar way to SSRIs, but as well as increasing levels of serotonin they also increase another transmitter noradrenaline
describe tricyclics
reserved for those that SSRIs do not work for
an older antidepressant and has more severe side effects than SSRIs so is only used on those that other drug therapies have not worked
strength of biological treatments for OCD - practical application
drug treatments
if one of key factors involved in OCD is (for example) lower levels of serotonin because of the mutation of the SERT gene then this knowledge can lead to drugs being prescribed to correct imbalance
one particular form of drugs that have been used are called SSRIs
SSRI medication, successfully used to reduce OCD symptoms and therefore shows the value that the biological explanation has in helping to improve the lives of people suffering from OCD
strength of biological treatments for OCD - cost effective and non disruptive
cheap compared to psychological treatments, therefore good value for NHS
non disruptive to people’s lives
if you wish, can simply take drugs until symptoms decline rather than spending time going to therapy
many doctors and people with OCD prefer drug treatments
limitation of biological treatments for OCD - serious side effects
minority of people taking SSRIs get no benefit
some people also experience side effects such as indigestion, blurred vision and loss of sex drive
for those taking clomipramine side effects are more common and can be more serious
more than 1 in 10 people experience erection problems and weight gain
quality of life is poor, may stop taking drugs altogether, reducing effectiveness of treatment
limitation of biological treatments for OCD - deterministic
this is because is states that OCD is determined or caused by internal biological factors such as genetics or neural factors
as a result, people who are suffering with OCD have no control over their behaviour, they have no free will and are unable to change
this is a rather pessimistic view of the condition as it implies that they can’t improve and their behaviours are inevitable
it could be argued that this deterministic view could further add to anxiety that those suffering with OCD already experience
therefore, suggests that the biological explanations are rather limited in its view of OCD because of the lack of choice it sees people have to manage it
