biological approach to explaining OCD Flashcards
what are the 2 explanations?
- genetic explanation
- neural explanation
what are the key details of the genetic explanation?
- inherit genetic vunerability
- candidate genes
- ocd is polygenic
- aetiologically heterogenous
explain genetic vulernability in relation to OCD
individuals have greater vunerability to first degree relatives who have OCD
what is Lewis’ research?
37% OCD patients had parents with OCD. 21% had siblings with OCD
explain candidate genes in relation to OCD
specific genes that could be responsible for OCD. genes are involved with regulating development of serotonin system
how is OCD polygenic ?
its caused by combination of genetic variations to increase vunerability
what is Taylor’s research?
found theres upto 230 different genes that may be involved with OCD
what does the stress- diathesis model suggest?
certain genes leave people more LIKELY to develop mental disorder but not certain. environmental stress triggers condition
explain aetiologically heterogenous in relation to OCD
there are different complex forms of OCD so different genes involved in cause of each type. the origins of OCD vary from one person to another
evaluation of genetic explainations
S: good supporting evidence- Nestadt twin studies
S: evidence from animal studies- mice
L: could be environmental risk factors- cam trigger/ increase risk of developing OCD
what are the key details of the neural explanation?
- role of neurotransmitters: serotonin
- brain structures
- the worry circuit
explain the role of neurotransmitters
- low levels of serotonin means normal transmission of mood relevant info doesnt take place so mood/mental processes are affected.
- some OCD assicoated with reduced levels of serotonin caused by SERT gene (causes low level of serotonin)
- some OCD explained by reduction in functioning of serotonin system in brain
explain brain structures
some OCD associated with impaired decision making bc of brain structures:
- lateral frontal lobe: responsible for logical thinking + decision making= explains obsessive thoughts/complusions
- left parahippocampal gyrus: processes unpleasant emotions= explains disgust/anxiety/guilt
explain the worry circuit
two brain areas associated with OCD:
1- orbit frontal cortex: sends worry signals that are picked up by thalamus + directed around body
2- caudate nucleus: suppresses some of worry signals
what happens if the caudate nucleus is not working properly?
the worry signals do not get suppressed and a person worries too much which can cause OCD
