psychopathology ocd
OCD
30/09/24
Behavioural: 1. COMPULSIONS
Compulsions are REPETITIVE- sufferers feel they must repeat the same behaviours again
and again e.g. hand-washing- to ensure they are clean
Compulsions REDUCE anxiety- carrying out the compulsive behaviour relieves anxiety that the sufferer is feeling (so is negatively reinforcing) e.g. washing hands reduces fear of germs
Behavioural: 2. AVOIDANCE
Sufferers of OCD tend to try to manage their condition by AVOIDING the source of their
anxiety
E.g. avoiding putting the bin out if you have a fear of germs, avoiding touching door handles etc.
Emotional Characteristics:
Anxiety/Distress
Depression
Guilt and Disgust
Cognitive Characteristics:
Obsessive thoughts (thoughts that recur over and over again)
Hypervigilance (mega-alert!)
Awareness that their thoughts and behaviour are “excessive and unreasonable”
Biological Approach to Explaining OCD
Introduction
As far back as 1936 a psychologist cited that the majority of his patients had parents or
siblings with OCD.
This suggests that the condition could be biological (although in the case of the above it could be learned!!!)
The diathesis-stress model?
1. Neural Explanation- SEROTONIN
This neurotransmitter is believed to help regulate mood.
A neurotransmitter is a chemical messenger.
If serotonin levels are disrupted, that means that messages involving mood are not
reaching the right parts of the brain.
This could cause a disturbance in cognition, emotions and behaviour (OCD)
Neural Explanation 2. Dysfunction of brain areas
FRONTAL LOBE:
Some types of OCD (hoarding) seem to involve impaired DECISION MAKING.
Decision making takes place in the FRONTAL LOBE (behind your forehead).
There is research which suggests that the lateral part (sides) of the frontal lobe function
abnormally in OCD patients in comparison to controls
B) PARAHIPPOCAMPAL GYRUS
There is also evidence to suggest that the left parahippocampal gyrus- associated with
processing unpleasant emotions- functions abnormally in patients with OCD.
Linked to the serotonin explanation is the possibility that a FAULTY GENE has caused that disruption of serotonin:
A01- Candidate Genes
The SERT gene - 5-HTT - has been identified as a candidate gene for OCD.
This gene determines how effective the transport of serotonin will be around the brain
(across synapses).
Carrying the SERT gene causes a disruption to serotonin transportation and therefore OCD
A01
Genes involved in dopamine transportation have also been identified as possible causes-
particularly the COMT gene- (COMT regulates the production of dopamine)
A03- Alternative genes
However, Taylor (2013) has carried out a huge meta-analysis and uncovered over 230
different genes which could be implicated in the development of OCD.
Furthermore, psychologists believe that different types of OCD (hoarding, religious
obsession, germ obsession) could be caused by DIFFERENT genes.
The POSH term for this is “aetiologically heterogeneous” (origin for OCD has more
than one cause).
Using TWIN STUDIES
Twin studies can be used to show that OCD has biological roots because MZ twins share
100% of the same genes and DZ twins only share 50%.
By comparing concordance rates across both sets of twins we can separate out the effects
of nature and nurture.
If concordance rates are much higher in MZ twins, then this extra “likeness” should be due to genetics, because both MZ and DZ twins share the same environment.
The higher the concordance rate in MZ compared to DZ twins, the stronger the
evidence for Biology.
Support From Twin Studies
There are many twin studies which have found support for the hypothesis that OCD is
genetic
E.g. a meta – analysis by Nestadt (2010) found 68% of MZ twins shared OCD compared to
31% DZ twins
Furthermore, family studies have shown that people with a first degree relative with OCD have a 5 times greater chance of developing it themselves!
\-ve Inconclusive
There are many issues with FAMILY studies- particularly pertinent is that it is very difficult to separate out the effects of nature (biology) and nurture (environment) when people grow up in the same home.
They could just be copying each other or learning from one another.
Concordance rates for twin studies are never conclusive- (never 100% vs 0%) so the DIATHESIS STRESS model could be the most VALID explanation.
Alternative Explanation
There is an abundance of evidence to suggest that many sufferers of OCD have suffered a
traumatic event in their past.
Therefore some psychologists believe that in fact NURTURE is much more important than NATURE in explaining this disorder
+VE Real life Application
The fact that anti-depressants can be used to drastically reduce OCD symptoms (i.e. they
work!) gives validity to the neural explanation.
I.e. if drugs which INCREASE the transportation of serotonin cure the
symptoms of OCD, then the theory must be valid!
Hundreds of supporting studies have been published, all lending validity to this theory.
OCD TREATMENTS
We have already learned that one major biological explanation of OCD is low levels of
serotonin.
It therefore follows that one major treatment for OCD involves taking drugs that INCREASE levels of serotonin in the brain.
In a person with a healthy serotonin system, the serotonin is released from the presynaptic neuron, travels via the synapse and is then absorbed via the postsynaptic neuron.
In OCD patients, something is malfunctioning in this system.
SSRIs STOP the reuptake of serotonin by the presynaptic neuron, and its breakdown, allowing more to flow through the synapse and be absorbed by the postsynaptic neuron.
Dosage varies according to the type of SSRI.
Fluoxetine is the most common. 20mg is a typical starting dose.
It usually takes at least 6 weeks of being in the system before a change in symptoms is
noticed.
Alternatives to SSRIs:
If SSRIs have been taken long term with no benefits, then two alternative drugs can be
tried:
Tricyclics: (older type of anti-depressant) which have more severe side effects
SNRIs (serotonin-noradrenaline reuptake inhibitors) new in the last five years.
A03- EVALUATION
Effective +ve
SSRIs have a huge body of research backing their efficacy.
Typically, research uses randomised controlled trials with pps randomly allocated
either the SSRI or a placebo.
Soomro (2009) reviewed 17 studies and found that SSRIs were more effective than placebos at curing OCD
2. Combining Treatments +ve
Research shows that the most effective way of treating OCD is to use a combination of
psychological and biological treatments.
The “dream team” combination appears to be CBT and SSRIs according to research.
By combining treatments we are tackling both BIOLOGICAL and PSYCHOLOGICAL
components which is always likely to be more effective!
3. +ve Cost-effective
Drugs are much more cost effective than psychological treatments.
Using drugs to treat OCD is therefore beneficial for the NHS as it cuts costs (in
comparison to paying for someone to have short-term CBT, for example).
(We will come back to this when we look at Psychology and the Economy)
4. Issues with drugs-ve
SIDE EFFECTS: SSRIs - indigestion and blurred vision. For Tricyclics- weight gain and tremors -even in extreme cases increased risk of suicide.
TOLERANCE is an issue- patients begin to need a higher dose for the drug to have the
same effect
ADDICTION is another issue- whether that be psychological or physical
5. What if Biology is not the cause? -ve
Using drugs to treat OCD is obviously going to be effective if biology is at the root of each
individual’s disorder.
However, for some people, who psychologists have already identified have developed OCD due to trauma, this is not going to be an effective or suitable treatment! It will never get to the root of the problem- just mask it by treating the symptoms and not the cause.