Psychopathology: OCD (L11-13) Flashcards
What is OCD?
- an anxiety disorder where anxiety arises from both obsessions and compulsions
- compulsions are a response to obsessions and the person believes that compulsions will reduce anxiety
What are the behavioural characteristics of OCD?
- compulsions/repetitive behaviour
- avoidance
What are compulsions/repetitive behaviour, BC?
- repetitive actions that could seriously hinder the person’s ability to perform everyday tasks
- compulsive behaviours reduce the anxiety that is created by obsessions
- the person feels they must perform these actions otherwise something dreadful might happen
- e.g. washing their hands over and over again or constantly checking the oven is switched off
What is avoidance, BC?
- some sufferers attempt to reduce their anxiety by avoiding situations that might trigger it
- sufferers who wash their hands continuously might avoid coming into contact with germs
by never emptying their bins
What are the emotional characteristics of OCD?
- high anxiety/low mood
- disgust/self-loathing
What is high anxiety/low mood, EC?
- obsessions and compulsions are a source of considerable anxiety and distress
- sufferers aware that their obsessions and compulsive behaviours are excessive and this causes feelings of embarrassment and shame
- sufferers might also be aware that they can’t consciously control their compulsive behaviours
- which leads to strong feelings
of distress
What is digest/self loathing, EC?
- feelings of disgust may be directed at the source of
the obsession - e.g. dirt and germs
- or they may be directed towards the self
What are the cognitive characteristics of OCD?
- obsessions/obsessive thoughts/irrational beliefs
- insight into irrationality of thoughts+behaviour/awareness that behaviour is irrational
- hyper-vigilance/selective attention
What are obsessions?
- persistent, intrusive, irrational thoughts that are perceived as inappropriate or forbidden
- may be frightening or embarrassing and the person might not want to share them with others
- common obsessions include doubts (have they checked
the cooker is switched off?) - impulses (to shout and swear in public) or images
- these obsessions are not worries about everyday problems; instead they are
uncontrollable and cause anxiety - they can include catastrophic thinking when people with OCD think that something terrible will happen if they do not carry
out their compulsions
What is awareness that behaviour is irrational?
- most sufferers understand their compulsive behaviours and obsessive thoughts are
inappropriate and irrational - but they cannot consciously control or stop them
What is selective attention?
- increased awareness of source of obsession in new situations
- e.g. constantly worrying about germs
What are the biological explanations of OCD?
- genetic explanations
- neural explanations
What are the genetic explanations for OCD?
- inheritence
- COMT gene
- SERT gene
What is the genetic explanation for OCD concerning inheritance, BE?
- suggest that OCD is an inherited condition and so a
vulnerability to developing the condition is passed on across generations - OCD is considered to be polygenic
- means that one single gene is NOT responsible for the disorder
- instead, as many as 230 genes might be responsible for
causing OCD - they are known as candidate genes
- aetiological heterogeneity
suggests that different combinations of genes may cause the disorder in
different people - different combinations of genes may also account for
different types of OCD
What is the genetic explanation for OCD concerning the COMT gene, BE?
- COMT gene may have a role in causing OCD
- gene regulates the production of a neurotransmitter called dopamine
- one variation of the COMT
gene results in higher levels of dopamine - this variation has been found to be more common in OCD patients than in people who do not have the disorder
-ve Evaluation, GE, BE:
- around half of all cases of OCD tend to follow trauma
- undermining the
genetic explanation of OCD
= explanation can’t account for cases of OCD in families where there is no previous history of OCD
What are the neural explanations for OCD, BE?
neurotransmitters
- dopamine
- serotonin
What is the neural explanation for OCD concerning dopamine, BE?
- neurotransmitter that affects mood
- abnormal levels are associated with abnormal transmission of mood related information
- OCD sufferers have high levels of dopamine
- high dopamine levels have been linked to over hyperactivity in the basal ganglia area in the brain
- this causes repetitive motor functions, e.g. compulsions
What is the neural explanation for OCD concerning serotonin, BE?
- neurotransmitter that affects mood
- abnormal levels are associated with abnormal transmission of mood related information
- plays a key role in operating the caudate nucleus in the basal ganglia of the brain
- seems that low levels of serotonin cause the caudate
nucleus to malfunction - low levels of serotonin result in obsessions
+ve Evaluation, NE, BE:
- antidepressant drugs increase serotonin levels in OCD patients
- this has lead to a reduction in OCD symptoms
- therefore good evidence to suggest that low levels of serotonin could be a cause for OCD
-ve Evaluation, NE, BE:
- neurotransmitters such as dopamine and serotonin might not necessarily cause OCD
- instead low levels of serotonin and high levels of dopamine might be a symptom of OCD
What does the biological approach use to treat OCD?
- uses drug therapy to correct the imbalance of neurochemicals like serotonin in order to reduce symptoms
What are the biological treatments for OCD?
- selective serotonin re-uptake inhibitors, SSRIs
- benzodiazepines
How do SSRIs treat OCD?
- one method is anti-depressant drugs called Selective Serotonin Re-Uptake Inhibitors
- these include Prozac, Fluoxetine etc.
- serotonin is released by presynaptic neurones, brain cells
- and travels across the synaptic cleft, gap between neurones
- it chemically conveys
the signal from the presynaptic neurone to the postsynaptic neurone - is then reabsorbed, re-uptake by the presynaptic neurone
- where it is broken down and reused
- SSRIs prevent the reabsorption and breakdown of serotonin
- so increase the level of serotonin in the synapse, where it continues to stimulate the postsynaptic neurone
- the effect of this should be to
reduce anxiety - typically takes 3-4 months of daily use for SSRIs to impact upon symptoms
- the typical daily dosage of SSRI may be increased if it is not benefitting the patient as appropriate
+ve Evaluation SSRIs:
- Soomro reviewed 17 studies that compared SSRIs to placebo
drugs for treating OCD - found that all 17 studies showed that SSRI drugs were more effective than placebos
- especially when SSRIs were
combined with Cognitive Behavioural Therapy, CBT
= 70% of patients have experienced a decline in OCD symptoms when taking SSRIs
= the remaining 30% of patients tend to opt for psychological therapies or a combination of SSRIs and psychological therapies
-ve Evaluation SSRIs:
- they have severe side effects which might mean that the OCD patient might stop taking the medication
- side effects are temporary but include indigestion, blurred vision and loss of sex drive
How do benzodiazepines treat OCD?
- anti-anxiety drugs, such as BZ, are commonly used to
treat OCD - BZs, e.g. Valium and Diazepam slow down the activity of the
cns by enhancing the activity of the neurotransmitter GABA - this neurotransmitter has an inhibitory effect on neurones
- GABA does this by reacting with special sites called GABA receptors on the outside of neurones
- when GABA locks into these receptors it opens a channel that increases the flow of chloride ions into the neurone
- chloride ions make it harder for the neurone to be stimulated by other neurotransmitters
- so slows down neural activity and making a person feel more relaxed
-ve Evaluation BZs:
- if BZ drugs are used long-term then several unwanted side effects can begin to appear
- e.g. drowsiness, depression and unpredictable interactions with alcohol
- Ashton found that long-term users of BZ became very dependent on the drug and sudden withdrawal of drug leads to return of high levels of anxiety and OCD symptoms
- is also the problem of tolerance whereby patients
need to take larger and larger doses of the drug in order to reduce their OCD symptoms as body gets used to the drug