ocd Flashcards
behavioural characteristics of OCD are
compulsions, avoidance of anxiety-inducing situations, reduction in social interactions
emotional characteristics of OCD are
anxiety, depression developed
cognitive characteristics of OCD are
obsessions, sufferer understands that they are irrational
the genetic explanation says that OCD is
inherited
OCD often have - genes
COMT and SERT
the COMT gene controls
dopamine levels
Tukel (2013) found that
high levels of dopamine were common in OCD sufferers
what is serotonin’s function
to regulate anxiety
the SERT gene controls
the transport of serotonin
Ozaki (2003) found that
OCD sufferers may have a SERT mutation leading to lower serotonin levels
the neural explanation for OCD explains how
neurotransmitter levels lead to OCD
dopamine levels are - and serotonin levels are - in OCD sufferers
high, low
high activity levels in the - of the brain are associated with OCD
orbital frontal cortex (OFC)
the function of the OFC is to
send worry signals to the thalamus, leading to an impulse to act
the function of the caudate nucleus is to
suppress impulses from the OFC
the caudate nucleus may not be functioning, meaning that
OCD could be caused as sufferers have overactive impulses for minor threats
comer (1998) found that
serotonin levels can cause these areas of the brain to malfunction
pauls (2005)
found that 10% of OCD sufferers have a 1st degree relative with OCD
the overall biological explanation for OCD is that…
- genes cause OCD, as shown in Pauls (2005) study where 10% of those with OCD had a relative with OCD
- COMT and SERT genes cause high dopamine levels and low levels of serotonin
- Tukel (2013) found that high levels of dopamine were common in OCD sufferers
- Ozaki (2003) found that many OCD sufferers have a SERT mutation leading to low levels of serotonin
- OCD have high levels of OFC activity, which aren’t being surpressed by the caudate nucleus
- Comer (1998) found that serotonin levels interfere with these areas
- overall COMT and SERT genes cause high dopamine and low serotonin, low serotonin means that the caudate nucleus doesn’t suppress enough signals from the OFC, causing people to worry irrationally and causing OCD
different genes cause OCD in different people; it is
aetiologically heterogeneous
Taylor (2013) found that
up to 230 genes are associated with OCD
a strength of the biological explanation for OCD is that it has good supporting
research evidence from twin studies, including Pauls (2005), where 10% of OCD sufferers had OCD, and Nestadt (2010) found that MZ twins had 68% concordance as opposed to 31% in DZ twins
what did Nestadt find and when
2010, MZ twins had 68% concordance in OCD as opposed to 31% in DZ twins
a strength of the biological approach to explain OCD is that SSRIs
have been proven to treat OCD by Soomro (2009), suggesting the biological approach has successfully identified serotonin levels being low is a cause of OCD
what did Soomro find and when
2009, 70% of people on SSRIs have a reduction in OCD symptoms
a weakness of the biological approach to explain OCD is that the genetic explanation is supported by twin studies,
which lack validity as twins have a shared environment, MZ twins may have higher concordance as they have more similar experiences, not due to genes
a weakness of the biological approach to explain OCD is that many OCD sufferers
have undergone traumatic experiences; Cromer (2007) found that over 50% of OCD sufferers had undergone trauma, so it may be that OCD is caused by traumatic experiences not by biology
what did Cromer find and when
2007, over 50% of OCD sufferers had undergone trauma
SSRI stands for
serotonin reuptake inhibitor
SSRIs are usually prescribed alongside
CBT
if SSRIs don’t work in 3 months,
their dosage is increased and they can be combined with tricyclics and SNRIs
SSRIs assume a
chemical imbalance
serotonin is released by
presynaptic neurons
where do we find presynaptic neurons
in the brain
after being released by presynaptic neurons, serotonin travels
across the synapse
after travelling across the synapse, serotonin binds to
receptor sites on the postsynaptic neurons
serotonin binding to receptor sites on the postsynaptic neurons has the effect of
conveying the signal across the synapse
after conveying the signal across the synapse, serotonin is
reabsorbed to be broken down by the presynaptic neuron
SSRIs prevent the
reabsorption and break down of serotonin, increasing serotonin levels in the synapse
a strength of the biological approach to treat OCD is that we have good
supporting evidence as 70% of OCD sufferers had a reduction in symptoms
what % of sufferers of OCD had some improvement in their symptoms on SSRIs?
70
a strength of SSRIs is that they are
cost effective
a weakness SSRIs is that supporting research for them is
provided by the drug companies who manufacture them, so they may be biased
a weakness f SSRIs is that they have a
higher relapse rate than CBT in 12 weeks
45% on SSRIs, 12% on CBT
what % of people on SSRIs relapse after 12 weeks
45
what % of people on CBT relapse after 12 weeks
12
