OCD: biological explanations Flashcards
(16 cards)
What are the two explanations for OCD?
Neural structure
Genes and inheritance
What does the neural explanation of OCD assume?
NTs play a role in the development of the disorder
What are the two key neurotransmitters in the neural explanation?
Serotonin and dopamine
How are serotonin and OCD linked?
Low levels of serotonin - low mood - faulty information processing in the frontal cortex of the brain - difficulty in applying logic, reason and rationality to thoughts and behaviours, making obsessive thoughts more likely.
How are dopamine and OCD linked?
Motivation and reward - compulsion
Abnormally high levels found in OCD patients
High levels lead to over activity in basal ganglia which responds to and processes thoughts
What does the genetic explanation of OCD assume?
Mental illnesses are heritable
Is OCD polygenic? - who found at least 230 genes involved in OCD?
Yes - Taylor (2013)
What genes have been linked to OCD?
COMT and SERT
What does the COMT gene do?
Regulates the production of dopamine and has been found to be more common in people with OCD. This causes an increase in dopamine levels
What does the SERT gene do?
Affects the transport of serotonin which therefore creates lower levels.
Evaluate the neural explanation of OCD (antidepressants)
Antidepressants such as SSRIs, which are used to regulate serotonin levels, have been effective in reducing OCD symptoms
Supports the idea that irregular levels of serotonin are linked to the development of OCD, increasing the validity of the theory
However, not all OCD sufferers respond positively to OCD which reduces the external validity
Evaluate the neural explanation of OCD (neural abnormalities)
Did OCD cause neural abnormalities or did neural abnormalities cause OCD? research is inconclusive
Evaluate the neural explanation of OCD (alternate explanations)
Behaviourist explanation may be plausible
Compulsions as negative reinforcement, removal of unpleasant stimuli (obsession)
Evaluate genetic explanation of OCD (twin studies)
Supported by twin studies
Nestadt (2010) found a 68% concordance rate in MZ twins and a 31% concordance rate in DZ twins
Increases validity of theory
However, concordance is not 100% between MZ twins suggesting the role of the environment
More plausible explanation may be diathesis-stress model
Evaluate the genetic explanation of OCD (biological reductionism)
Ignoring the role of the environment means the explanation is prone to biological reductionism
Evaluate the genetic explanation of OCD (alternate explanations)
Behaviourist explanation may be more plausible
Compulsions as negative reinforcement
