OCD (obsessive compulsive disorder) Flashcards
what are obsessions?
recurring intrusive thoughts
what are compulsions?
repetitive behaviours carried out in order to alleviate anxiety caused by the obsessions
what are the emotional characteristics of OCD?
- feelings of embarrassment and shame as they are aware their behaviour is excessive
- both obsessions and compulsions are a source of considerable anxiety and distress
what are the behavioural characteristics of OCD?
- compulsive behaviours are performed to reduce the anxiety caused by obsessions and they’re repetitive
- patients feel they must perform these actions i.e may think something dreadful will happen if they dont
what are the cognitive characteristics of OCD?
- recurring intrusive thoughts or impulses (inappropriate)
- at some point the patient does not recognise that the obsession/compulsion is excessive
- ideas, doubts, images or impulses
what are the three branches of biological explanation for OCD?
genetics
neurochemistry
neuroanatomy
what is the SERT gene?
it affects the transport of serotonin, creating lower levels of neurotransmitter
what is the COMT gene?
- it regulates the production of the neurotransmitter dopamine
- one allele of COMT gene is more common in OCD patients
- this allele produces lower activity of COMT leading to higher levels of dopamine
what is dopamine?
- a neurotransmitter in the brain which is thought to be abnormally high in OCD sufferers
what is serotonin?
- its a chemical messenger
- low levels are found in OCD sufferers
- antidepressants that increase levels of serotonin activity have been shown to reduce OCD symptoms
what is concordance rate?
the measure of genetic similarity
describe neuroanatomy (brain structure)
the worry circuit:
- the OFC sends ‘worry’ signals/impulsive thoughts to the thalamus
- irrelevant ones are suppressed by the caudate nucleus
- in OCD patients there is damage to the caudate nucleus meaning these minor worries aren’t suppressed
what role does serotonin play in neuroanatomy (brain structure)?
- plays a key role in the operation of the OFC and caudate nucleus - reduced levels of serotonin in the brain can cause these areas to malfunction
give another explanation for OCD in patients
the left parahippocampulgyrus functions abnormally in OCD patients - this part of the brain is associated with processing unpleasant emotions
treating OCD: drug therapy
drug therapies aim to change the levels of neurotransmitters in the brain or to change their activity
explain how drug therapy works
- neurotransmitters are released from one neurone across the synaptic gap and attach to receptors on another neurone.
- they then go back to the first neurone called ‘reuptake’.
(the longer they are in the gap and on the receptors, the greater the effect)
what are the three types of antidepressants?
SSRIs
SNRIs
Trycylics
explain how SSRIs work
(selective serotonin reuptake inhibitor)
- they act on the neurotransmitter serotonin and inhibit the reuptake of serotonin meaning it stays in the synaptic gap for longer increasing the levels
- the take 3-4 months of daily use to have an impact on symptoms
explain the use of SNRIs
if a patient does not respond to SSRIs even after an increased dosage then their medication may be changed to SNRIs - which increase the levels of serotonin and noradrenaline
explain the use of tricyclics
if SNRIs fail then tricyclics are used - they have the same effect on the serotonin system as SSRIs but have much more severe side effects
what is another drug therapy used?
anti-anxiety drug
- these work by enhancing the activity of GABA (which is a neurotransmitter that regulates excitement in the nervous system and makes a person feel more relaxed, reducing anxiety
what what are limitations of drug therapy?
- has side effects
- not effective in the long-term as it doesn’t provide a long-lasting cure
- publication bias
what is a strength of drug therapy?
- they are more economical for the health service than psychological therapies
