ocd ao1 Flashcards
what is ocd
A condition characterised by obsessions and/or compulsive behaviour. Obsessions are cognitive whereas compulsions are behavioural.
2 main components of ocd and differences
Compulsion= behaviour external component(something you feel the need to do) - beh done rep to alleviate anxiety
Obsession= about cognition internal component (is something you think about.) unwanted intrusive thoughts or images that cause distress
3 cogntive characteristics of ocd
Obsessive thoughts- For sufferers of OCD, these thoughts occur over and over again.
Eg: Fear of contamination, by dirt or germs; Fear of safety, by leaving doors or windows; religious fears, from being immoral; perfectionism, a fear of not being the best.
Cognitive coping strategies
sufferers of OCD adopt cognitive strategies to deal with their obsessions. For example, suffers with religious obsessions may pray over and over, to reduce their feelings of being immoral.
insight into excessive anxiety
sufferers of OCD know that their obsessions and compulsions are irrational and experience selective attention directed towards the anxiety-generating stimuli (similar to the selective attention found in phobias).
5 emotional characteristics of ocd
Anxiety and distress Unpleasant emotional experiences are due to powerful anxiety which is often paired with obsessions and compulsions. These emotions are overwhelming.
Accompanying depression
the anxiety experienced can often result in a low mood and loss of pleasure in everyday activities
Guilt and disgust
Obsessions are persistent and/or forbidden thoughts and ideas, which cause irrational guilt over a minor moral issue for example or disgust directed at something external like dirt or even the sufferer themselves
3 beh characteristics of ocd
Compulsions are repetitive (e.g. excessive hand washing)
sufferers will often feel compelled to repeat a behaviour
Compulsions reduce anxiety
for example, the excessive hand washing is caused by an excessive fear of germs and bacteria and is therefore a direct response to the obsession.
Avoidance
Suffers may attempt to avoid situations which might trigger compulsions. They try to manage their OCD for example, people who compulsively hand wash may avoid taking out bins or going outside where germs may be present. This can then interfere with their lives.
3 concepts of biological explanation of ocd
role of genes - genetic explanation
role of neurotransmitters
role of brain structures -both neural explanations
genetic explanations of ocd focus on
dentifying particular genes which are implicated in OCD.
names of genes associated w ocd and what kind of genes are they
2 candidate genes
COMT genes
SERT gene
ocd is described as a _______ condition
polygenic condiotion
polygenic means..
multiple genes that might be involved with the development of OCD. whereby combination of genes that together increase vulnerability.
research support for polygenic ocd
taylor 2013 suggets that there are as many as 230 genes associated w ocd after analysing previous studies
these included action of dopamine and serotonin - neurotransmitters believed to have a role in regulating mood
role of compt gene
The COMT gene is associated with the production and regulation of the neurotransmitter dopamine.
One variation of the COMT gene results in higher levels of dopamine and this variation is more common in patients with OCD, in comparison to people without OCD.
role of sert gene aka 5 htt gene
he SERT gene is linked to the neurotransmitter serotonin and affects the transport of the serotonin (hence SERotonin Transporter), causing lower levels of serotonin which is also associated with OCD (and depression)
research support for genetic explanation of ocd
Classic study by Lewis (1936) observed OCD in patients and found 37% have parents with OCD and 21% had siblings with OCD. This suggested that OCD can run in families.
MZ twins have a higher concordance rate for OCD than DZ twins. Billet et al (1998) 68%MZ and DZ 31%.
However, this explanation implies a genetic vulnerability/ predisposition rather than a guarantee. According to the diathesis- stress model certain genes leave some people more likely to develop mental disorder but is not certain. Instead, it is suggested that certain environments are most likely to trigger the development of the condition.
neurotransmitters involved in ocd
serotonin
dopamine
serotonin role
Serotonin regulates mood and lower levels of serotonin are associated with mood disorders, such as depression.
abnormal levels of neurotransmitter serotonin may be caused by …
SERT gene
research support for serotonin playing a role in ocd
piggott et al 1990 and jenicke 1992 - antidep that increase serotonin lead to reduction in ocd symptoms whereas antidep that didnt have no effect
role of dopamine in ocd
higher levels of dopamine being associated with some of the symptoms of OCD, in particular the compulsive behaviours.
structures in brain associated w ocd
abnormal brain circuits in reigons in frontal lobes
orbitofrontal cortex
basal ganglia
caudate nucleus
role of ofc in ocd
sig role in emotions
relays info ab worries and converts emotions into actions
ev for ofc role in ocd
This is supported by PET scans of patients with OCD, taken while their symptoms are active. (eg someone with germ obsession holds dirty cloth)
Cromer et al (1998) reports serotonin and dopamine are linked to these regions of the brain.
basal gang func in ocd
coodination of movements
distributes serotonin and controls emotional and cog functions
ev for basal gang func in ocd
Max et al. (1994) found that when the basal ganglia is disconnected from the frontal cortex during surgery, OCD-like symptoms are reduced, providing further support for the role of the basal ganglia in OCD.
caudate nuc func
Caudate nucleus- acts as a filter suppresses messages from OFC
name biological treatments of ocd
SSRIS - Selective serotonin reuptake inhibitors -anti dep drug
stress/anxiety relif - benzodiazepines
How are neurotransmitters different from impulses?
The impulses send signals from the body to the brain; (electrical)
neurotransmitters send signals from the brain to the body. (chemical)
aim of ssris
increase levels of serotonin
explain how serotonin works in normal ppl
serotonin is rel by presynaptic neuron into synapse where the neurotransmitter diffuses across the synapse
until it reaches receptor sites on post synaptic neuron, triggers electrical impulse
serotonin is reapsorbed and broken down
how does serotonin transmissioj differ in those w ocd
less serotonin is being rel from presynaptic neuron
or
serotonin reabsorbed to quickly in post synaptic neuron
how do ssris work
designed to block reapsorbtion of serotonin so thus increasing it levls in the synapse
this means its more likley to bind to receptor sites on post synatic neuron
compensating for lack of serotonin that would naturally be in th individuals system
structure an outline for ssris
1- what ssris are and what they aim to do
2 - how do they work
3- what is the theory behind them eg ppl w ocd rel too little or reabsorb to much serortonin so blocks reuptake and leads to normal transmission about information relating to mood
4- what is the result - red cd symptoms
what is benzodiazepines
anti anxiety medicatio
how does benzodiazepines work
increases the effect of gaba
gaba has inhibitory effect -tells neurons to stop stressing
what is gabba
neurotransitter for natural stress inhibition
how does gaba work
gaba has inhibitory effect -tells neurons to stop stressing
when gaba locks onto receptor site the flow of choride ions into the neuron is increased
chloride ions make it more difficult for receving neuron to be stimulated by further neurotransmitters
thus the nervous system is slowing down making patient feel more relaxed
gaba affects the flow of ______ ions
chloride ions
when gaba locks into receptor site the flow of choride ions into neuron in increased - what is the effect of this
more difficult for receving neuron to be stimulated by further neurotransmitters
thus the nervous system is slowing down making patient feel more relaxed
benzodiazepies enhance gabbas effect by
bz combine w gabba receptors - chanells open more often so more chance of choride ions flowing into neuron so more -ve charged, neuron less likely to fire to increased calming effect
bz affect on cns and ocd
general quieting influence on cns
reduction in anxiety expirenced as a result of obsessive thoughts common in ocd is reduced
less obsessions - less compulsions - imporvment of symptoms
2 alt to ssris
tricyclics
SNRIS
WHAT are tricyclics
older type of anti-depressant which acts on various systems including the serotonin system where it has the same effect as SSRI
dis to tricyclics
people have extreme side effects to this
what are SNRIS
(serotonin -noradrenaline reuptake inhibitors) have recently been used. They are a different type of antidepressant. SNRI’s increase levels of serotonin as well as other different neurotransmitter-noradrenaline. so effective for those who dont responf to SSRIS afer 3 months
gaba tells neurons to stop firing - how much % of brains nuerons responfd to gaba
40%
