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ALL will understand biological explanations
and treatments for OCD
MOST will be able to explain biological
explanations and treatments for OCD
SOME will be able to explain and evaluate
biological explanations and treatments for
OCD
DO NOW: look at the PSYB2 paper on
your desk, would you be confident on
which sections you ought to answer?
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Nothing which you have been taught is ‘wrong’
it can all still be used as evaluation in your essays
What has changed is that the exam board want
you to know for OCD only bio and cog
explanations and treatments
These should be the explanations and
treatments you should focus on for your revision
as you could be asked about them directly
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With the person next to you write down two
symptoms which a person diagnosed with
OCD would have.
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1.
2.
3.
This breaks down into 3 components:
Genetic
Biochemical
Neurophysiological
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1.
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This breaks down into 3 components:
Genetic
It has been proposed that there is a genetic component to
OCD which means some individuals might be more likely to
get it according to their family history of anxiety disorders
McKeon and Murray (1987) found that patients with OCD are
more likely to have an immediate (first degree) relative with
an anxiety disorder suggesting a genetic link
Pauls et al (1995) found a much higher percentage of OCD
sufferers (10.3%) in relatives of patients with OCD than in a
control group without OCD (1.9%)
This breaks down into 3 components:
2. Biochemical
 OCD only responds to those drugs that affect
serotonin; this suggests that OCD is related to low
levels of the neurotransmitter serotonin in the
brain.
 Drugs which increase the amount of serotonin
known as ‘SSRIs’ reduce OCD symptoms, therefore
providing support for the theory that low levels of
serotonin may be responsible for OCD.
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This breaks down into 3 components:
3. Neurophysiological
 Neuroimaging techniques (e.g. PET
scans) have shown that a part of the
brain known as the basal ganglia may
have a part to play in OCD.
 Rapoport and Wise (1988) suggested
that hypersensitivity of the basal
ganglia gives rise to repetitive motor
behaviours such as those found in OCD
patients, e.g. repetitive handwashing.
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Genetic explanation evaluation
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(-) findings from family studies used to
support the genetic explanation could be
explained by environmental influences, e.g.
observing and imitating behaviour shown by
relatives (SLT)
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Biochemical explanation evaluation
(-) Studies on SSRIs which increase levels of
serotonin only report a 50% improvement in
symptoms suggesting that there are other
explanations of OCD
(-) There is a time delay before any
improvement in OCD is noticed, taking SSRI
medication doesn’t improve symptoms for 412 weeks
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Neurophysiological explanation evaluation
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(-) evidence for structural abnormality in the
basal ganglia is inconsistent. Aylward et al
(1996) found no significant differences in the
basal ganglia structures of OCD patients and
controls.
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January 2009 (b) Outline one of the biological
explanations for obsessive-compulsive
disorder. (3 marks)
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Answer this now to test your knowledge and
understanding
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Likely answers for genetic, biochemical and physiological explanations:
Genetic explanation: some people are genetically predisposed to develop
the disorder. Support for the proposal from family studies which indicate
that first degree relatives of OCD sufferers are more likely to also exhibit
the disorder.
Biochemical explanation: treatment with drugs which increase serotonin
levels results in improvement suggesting that low levels of serotonin are
a cause of OCD.
Physiological explanation: basal ganglia is an area of the brain
responsible for psychomotor functions, some researchers have
suggested that OCD sufferers might have hypersensitivity of the basal
ganglia which results in repetitive movements
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SSRIs are a group of anti-depressant medications which are the most
widely prescribed drugs for anxiety disorders.
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SSRIs increase the levels of the neurotransmitter serotonin in the brain
by preventing the reabsorption of serotonin at synapses (spaces between
nerve cells). Because depression frequently accompanies OCD, SSRIs are
particularly beneficial for this anxiety disorder.
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MAOIs are an older type of anti-depressant which are sometimes used
for those who gain no benefit from SSRIs
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http://www.youtube.com/watch?v=HryOhK4E7aU
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Evaluation of biological treatments of OCD
(+)SSRIs are easily tolerated and are safe,
even for older patients. They are not
addictive and can be used in the long-term.
(+) Drug treatment is quicker and cheaper
than psychological therapies
(-) SSRIs cause side effects (headaches, nausea, sexual
dysfunction), there can be relapse when coming off the
medication
 (-) SSRIs take 4-12 weeks before any therapeutic effect is
noticed, this, together with side effects, this can cause
people to stop taking the medication
 (-) MAOIs are effective but they are last in line to be used for
treatment due to side effects e.g. weight gain, sexual
dysfunction.
 (-) A serious rise in blood pressure can occur when MAOIs are
combined with foods containing the amino acid tyramine
found in certain foods e.g. cheese, wine.
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Describe and evaluate two therapies for obsessivecompulsive disorder. (10 marks)
 If this type of question comes up your A01 must
consist of bio and cognitive treatments
 You can use what we have learnt for A02 as part of
the comparison
 You should bullet point your A01s and A02s for this
question now, you can complete it fully once we cover
cognitive treatments next week
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Describe and evaluate two therapies for
obsessive-compulsive disorder. (10 marks)
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[AO1 = 5, AO2 = 5]
AO1
Up to 5 marks for description of two of the following possible therapies. Likely points
include:
Drug therapy – treatment of anxiety by use of drugs that increase serotonin levels, eg
SSRIs. Other effects of these drugs on orbital frontal cortex.
Cognitive therapy – procedures: describing misinterpretation of thoughts, raising
awareness, use of ritual to neutralise obsessions, habituation training.
Combined behaviour and cognitive therapy described O’Kearney (1993).
Credit description of evidence up to 1 mark.
AO2 Up to 5 marks for discussion and evaluation of the therapies. Likely discussion
points
include:
Drug therapy: improvement found in 50-80% cases Julien (2005), reduction of symptoms
not elimination, relapse when drugs not taken, dual approach with other therapy eg ERP
effective and reduced need for surgery.
Cognitive therapy: how cognitive strategies work, effectiveness Rufer et al (2005)
Credit use of evidence.
Maximum 6 marks if only one therapy
Maximum 6 marks if no explicit link to OCD
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ALL will understand biological explanations
and treatments for OCD
MOST will be able to explain biological
explanations and treatments for OCD
SOME will be able to explain and evaluate
biological explanations and treatments for
OCD
Write down on your post-it note 3
things you have learnt and 1 question
you still have