The Biological Approach To Explaining And Treating OCD Flashcards
What are the 2 explanations of OCD?
Genetic explanations
Neural explanations
What is the diathesis-stress model? (OCD)
It suggests that certain genes may make people more vulnerable to OCD, but it is not certain - some environmental stress is needed to trigger the condition
What is the candidate gene: SERT gene?
A mutation of the gene causes lower levels of serotonin
What is the candidate gene: COMT gene?
A mutation of the gene causes higher levels of dopamine
Why does OCD seem to be polygenic?
Evidence has shown that up to 230 different genes may be involved in OCD
Which study provides evidence for the genetic explanation of OCD?
Nestadt et al (2010) - Review of twin studies
What were the concordance rates of Nestadt et al’s study?
MZ twins - 68%
DZ twins - 31%
What is a limitation of Nestadt et al.’s findings? (Concordance)
Results for MZ twins are not 100% concordant - if it was truly genetic, they would be 100% concordant
What’s a strength of Nestadt et al.’s study?
Reliable - reviewed a large amount of data
What does serotonin do?
Regulates mood and is a neurotransmitter
What are neurotransmitters responsible for?
Relaying information from one neuron to another
What do low levels of serotonin lead to?
Impaired transmission of mood-relevant information, leading to a lowered mood
What are low levels of serotonin also linked to?
Obsessive thoughts
What does abnormal frontal lobe functioning lead to?
Impaired decision-making, leading to symptoms of OCD
What is a strength of neural explanations for OCD?
Supporting evidence from antidepressant studies shows that increasing serotonin levels reduces OCD symptoms, suggesting serotonin has a role in the development of OCD
What is a limitation of the neural explanation for OCD?
Lack of understanding of what neural mechanisms are involved - incomplete explanation
How is OCD treated?
Through drug treatment which aims to alter levels or activity of certain neurotransmitters
What are drug treatments often used in conjunction with?
CBT
What are SSRIs?
Selective Serotonin Re-uptake Inhibitors - the most commonly used drug for OCD (and depression)
How do SSRIs work?
They prevent the reuptake of serotonin in the synaptic cleft. This means there’s more serotonin for the next neuron
How long does it take for the benefits of SSRIs to show?
Around 3-4 months
What are SNRIs?
Serotonin-noradrenaline reuptake inhibitors - an alternative for people who don’t respond to SSRIs
What are tricyclics?
An older type of antidepressants that are similar to SSRIs but have worse side effects. Often a last resort nowadays.
Which study supports drug therapy for OCD?
Soomro et al.
What did Soomro et al. find?
That symptoms of OCD reduce for approx 70% of patients when taking SSRIs. (Which were more effective than placebos)
What’s a strength of drug therapy for OCD?
It is easy and non-disruptive - patients just take a pill & don’t have to go to lengthy therapy sessions - more accessible to more people
What is a limitation of drug therapy for OCD?
Drugs can have side effects (e.g. nausea, headaches, loss of sex drive) - patients less willing to take the drugs - symptoms will return
