OCD Flashcards
What are the behavioural characteristics of OCD?
Compulsions/repetitive behaviour
Avoidance
How does a person with OCD demonstrate compulsions?
Repetitive actions that hinder ability to perform daily tasks
Reduces anxiety from obsessions
Person must perform compulsions otherwise consequences
How does a person with OCD demonstrate avoidance?
Avoid situations that may trigger their anxiety (avoiding emptying a bin to avoid germs)
What are the emotional characteristics of OCD?
High anxiety / low mood
Disgust / self-loathing
Why do people with OCD demonstrate high anxiety?
They are aware of their inability to control themselves
Why do people with OCD have a low mood?
They aware aware of their excessive behaviour which causes embarrassment
How do people with OCD demonstrate disgust/self-loathing?
They hate source of obsessions or themselves
What are the cognitive characteristics of OCD?
Obsessions/Irrational beliefs
Awareness of irrational behaviour
Selective attention
What is an obsessive thought?
Persistent, intrusive, irrational behaviour that is perceived as inappropriate or forbidden
What are common obsessions?
Doubts
Impulses
Images
How are people with OCD aware of their irrational behaviour?
They often know their thoughts are inappropriate/irrational but can’t consciously control them
How does a person with OCD demonstrate selective attention?
Increased awareness of source of obsessions in new situations
What does polygenic mean?
More than 1 gene is responsible for behaviour
What are candidate genes?
Genes that might be responsible for a behaviour
What are neurotransmitters?
Chemical messengers in the nervous system
What are the 2 biological explanations of OCD?
Genetic Explanation
Neural Explanation
What does the biological approach assume?
OCD is caused by genetic and biochemical factors
What does the genetic explanation suggest?
OCD is inherited
What 2 genes may have a role in causing OCD?
COMT gene
SERT gene
What does the COMT gene do?
Regulates production of dopamine
Variation of this gene causes more dopamine
This variation is more common in people with OCD
What does the SERT gene do?
Affects transportation of serotonin
Causes lower levels of serotonin which is linked to OCD
What are the strengths for the genetic explanation?
Animals studies
Nestadt et al (2010)
What did Nestadt et al do (2010)?
Concordance rates for OCD between monozygotic twins (68%) was higher than dizygotic twins (32%)
How do animals studies act as a strength for the genetic explanation of OCD?
Ahmari (2016) found a common gene in mice who display ritualistic behaviour
Suggests that behaviour may be caused by genes, like OCD
What is the weakness of the genetic explanation?
Limited explanation
- Cannot apply to families without a history of OCD
- Around half of OCD cases tend to follow trauma
What does the neural explanation suggest?
Abnormal levels of neurotransmitters causes abnormal transmission of mood-related information
What 2 neurotransmitters affect mood?
Dopamine
Serotonin
How does dopamine link to OCD?
High levels of dopamine is linked to hyperactivity in the basal ganglia of the brain
This causes repetitive motor functions
How does serotonin link to OCD?
Low levels of serotonin cause the caudate nucleus in the basal ganglia of the brain to malfunction which also causes compulsions
What is the strength of the neural explanation?
Antidepressants which increase serotonin levels have been shown to lessen symptoms of OCD
What is a weakness of the neural explanation?
OCD may cause abnormal levels of neurotransmitters or it may be the other way around
DON’T KNOW WHICH ONE COMES FIRST
What do the biological treatments for OCD focus on?
Correcting the balance of neurotransmitters to reduce symptoms
What are the two biological treatments for OCD?
SSRIs (selective serotonin re-uptake inhibitors)
Benzodiazepines
What are some examples of SSRIs?
Antidepressants such as:
Prozac
Fluoxetine
What are some examples of benzodiazepines?
Anti-anxiety drugs:
Valium
Diazepam
How does serotonin travel in the brain?
Released by presynaptic neurons
Travels across synaptic cleft / synapse
Chemically convert signals from presynaptic neuron to postsynaptic neuron
Reabsorbed by the presynaptic neuron - broken down and reused
What do SSRIs do to serotonin?
Prevent reabsorption and breakdown serotonin to increase the level of serotonin in the synapse
Serotonin continues to stimulate the postsynaptic neuron
Reduces anxiety
How long do SSRIs take?
Usually 3-4 months to impact symptoms
What are the strengths of SSRIs?
Research support (Soomro 2009)
Proven to decline symptoms
What did Soomro (2009) do?
Reviewed 17 studies comparing SSRIs to placebo drugs
All 17 studies shows SSRIs were more effective - especially when paired with CBT
How are SSRIs proven to decline symptoms?
70% patients experienced decline in OCD symptoms
Remaining 30% chose psychological therapies or both
What are the weaknesses of SSRIs?
May have sever side effects:
- indigestion
- loss of sex drive
- blurred vision
Can cause patients to stop taking the medication
What do benzodiazepines do?
Slow down activity on central nervous system by enhancing activity of GABA
What is GABA?
A neurotransmitter which has an inhibitory affect on neurons
How does GABA slow down activity of the CNS?
Reacts with GABA receptors on neurons
GABA locks on to these receptors and open a channel
Chloride ions flow through the channel making it harder for other neurotransmitters to stimulate it
Slows down natural activity and makes a person feel more relaxed
What is the strength of Benzodiazepines?
Can reduce anxiety and OCD symptoms in a short period of time - a lot faster than CBT and other treatments
What are the disadvantages of benzodiazepines?
Side effects
Dependency (Ashton 1997)
Increasing tolerance
What are some side effect of benzodiazepines?
Drowsiness
Depressions
Unpredictable interactions with alcohol
What did Ashton (1997) find?
Long-term users of benzodiazepines become dependent on it
Sudden withdrawal leads to return of high anxiety and OCD symptoms
