biological approach in EXPLAINING OCD

what is the biological approach ?

perspective that emphasises the importance of physical processes in the body such as genes and neural function

T of F , OCD is rooted largely in the cognitive approach ?

• false

• in biological approach

what are the two forms of biological explanation for OCD?

• genetic

• neural

what are involved in individual vulnerabilities in OCD?

genes

what did Lewis 1936 find about his patients with OCD ?

• 37% of patients had parents with OCD

• 21% had siblings with OCD

what did Lewis’ findings suggest about genes and OCD ?

• there is a genetic vulnerability to OCD that is passed down not a certainty of OCD

what is the diathesis-stress model?

model that suggests genes leave some people more likely to develop a mental health condition but it’s not certain

some environmental stress is necessary to cause the condition

what is the term for identified genes that create vulnerability for OCD ?

candidate genes

what are some candidate genes responsible for ?

regulating the development of serotonin system

what gene specifically is implicated in the transport of serotonin across synapses ?

5HTI-D beta

what is the term to describe OCD that refers to it not being caused by one gene but a combination of genetic variations that increase vulnerability ?

polygenic

what did Taylor 2013 find ?

230 different genes involved in OCD

genes studied next to OCD associated with dopamine and serotonin - mood regulators

what is the term to describe the variation of genes causing OCD in different people ?

aetiologically heterogenous

• OCD varies from one person to the other dependant on the group of genes

what is a strength of the genetic explanation for OCD ?

• research support

• evidence suggests some people are vulnerable to OCD due to genetic makeup

• twin studies - Nestadt 2010 reviewed twin studies and found that 68% of MZ twins developed OCD as opposed to 31% of DZ twins

• family studies too

• evidence for OCD 4 times more likely in someone with family member with diagnosis than someone without

• evidence using real life examples - increases external validity and suggests there is a link between genes and OCD

what is a weakness of genetic explanations for OCD ?

• lack of specific candidate genes

• evidence for genes involved in OCD but no specific findings of candidate genes

• only findings shown weak link between gene an OCD

• Pomohaibo reviewed evidence and concluded OCD as polygenic yet no findings show the definite genes that cause or lead to OCD

• the link between genes and OCD is limited and underesearched

what are the genes associated with OCD likely to affect ?

neurotransmitters as well as structures of the brain

what neurotransmitter is said to have role in regulating mood?

serotonin

what are neurotransmitters responsible for ?

relaying information from one neurone to the next

what does a person with low levels of serotonin experience and why?

low mood due to transmission of mood relevant information not occurring

aside from serotonin , what other factor is associated with OCD especially hoarding disorder ?

impaired decision making

what is impaired decision making associated with ?

atypical functioning of the lateral frontal lobes of the Brain

what are the frontal lobes responsible for?

logical thinking and decision making

what specific area of the brain is associated with OCD ?

left parahippocampal gyrus - functions atypically in OCD

what is the left parahippocampal gyrus responsible for ?

processing unpleasant emotions

what is a strength of the neural explanation of OCD ?

• research support

• evidence that antidepressants working on serotonin are effective in reducing OCD symptoms - SSRIs - reduces serotonin reuptake so levels of serotonin are increased in the synapse

• suggests serotonin is involved in OCD

• OCD - like symptoms form part of conditions known to be biologically originated such as parkinsons disease - causing muscles tremors

• if biological conditions like parkinsons produces OCD like symptoms then biological processes underlie OCD

• biological factors eg serotonin is responsible for OCD

what is a weakness of the neural model ?

• the serotonin- OCD link may be not be unique to OCD

• OCD and clinical depression are seen together - co-morbidity

• depression probably involves disruption to serotonin action

• is serotonin the basis of OCD ? or a result of depression alongside ?

• serotonin may be irrelevant to OCD symptoms