what approach is used to explain OCD?
biological approach
what are the two explanations of explaining OCD?
- genetic explanation
- neural explanation
what factors are included in the genetic explanation of depression?
- inherited
- candidate genes
- polygenic
- different types of OCD
who was the researchers involved in OCD being inherited?
Lewis
who proposed the diathesis-stress model?
Lewis
what did Lewis do?
- examined his patients with OCD and found that 37% of his patients had parents with OCD and 21% had siblings with OCD
= OCD runs in families from one generation to the next and this creates a genetic vulnerability not the certainity of OCD
what is the diathesis-stress model?
- certain genes leave some people more likely to develop a mental disorder but it is not certain
- some environmental stress is necessary to trigger the condition
what are candidate genes?
specific genes which create a vulnerability for a disorder
what are examples of candidate genes and what are their functions?
- COMT gene = regulates the neurotransmitter dopamine
- SERT gene = affects transport of serotonin
- 5HT1-D beta = transport of serotonin across synapses
what is meant by OCD is polygenic?
- OCD is not caused by one single gene but by a combination of genetic variations that together significantly increase vulnerability
who was the researcher involved in OCD being polygenic?
Taylor
what did Taylor find?
- analysed findings of previous studies and found evidence that up to 230 different genes may be involved in OCD
what is meant by different types of OCD?
- one group of genes may cause OCD in one person but a different group of genes may cause the disorder in another person
- this is called aetiologically heterogenous = origins of OCD vary from one person to another
what are different types of OCD caused by?
particular genetic variations, such as hoarding disorder and religious obsession
what does the neutral explanation suggest about OCD?
abnormal levels of neurotransmitters are linked to OCD
explain the role of serotonin In causing OCD.
- serotonin = regulates mood
- low levels of serotonin = normal transmission of mood relevant information doesn’t take place and person experiences low moods
explain the role of decision-making systems.
- OCD such as hoarding disorder is associated with impaired decision making
- which is associated with abnormal functioning of lateral of frontal lobes of brain
- frontal lobe = responsible for logical thinking and making decisions
- left parahippocampal gyrus is associated with processing unpleasant emotions and functions abnormally in OCD
