Biological Approach To Explaining OCD Flashcards
What is meant by the biological approach
Perspective emphasising importance of physical processes in body like genetic inheritance + neural function
OCD has stronger biological component than others
What are genetic explanations
-genes make up chromosomes + consist of DNA , codes for physical features of organism like eye colour + psychological (mental disorder)
-genes inherited
What is the genetic explanation for OCD
Genes- involved in vulnerability to OCD
-classic study by Aubrey Lewis observed of his OCD ppl, 37% had parents w OCD + 21% had siblings w OCD
- suggests OCD runs in family , but genetic vulnerability not certainty
-Diathesis stress model says some genes leave some people more likely to develop disorder but X certain
-> some environmental stress triggers
What are the role of candidate genes in explaining OCD
-genes identified that create genetic vulnerability
-some genes involved in regulating development of serotonin system for eg gene 5HT1-D beta is implicated in transport of serotonin across synapses
How does OCD being polygenic explain OCD genetically
-means OCD X caused by 1 single gene but combo of genetic variations that incr vulnerability
-Taylor found up to 230 dif genes may be involved in OCD
-genes that have been studied in relation to OCD include those associated with action of dopamine + serotonin , both neurotransmitters believed to have role in regulating mood
-(dopamine - feeling of reward) - serotonin (stable mood)
What are the different types of OCD as a genetic explanation
-1 group of genes may cause OCD in 1 person but dif groups of genes at cause disorder in another person
-aetiologically heterogenous - OCD has dif origins
-some evidence to suggest dif types of OCD may result from genetic variations
- hoarding disorder - type of ocd associated with impaired decision making in frontal lobe
- religious obsession
Whats a strength of the genetic explanation of OCD
Strong evidence base/research support to suggest some people are vulnerable to OCD
Result of genetic makeup
Eg Nestadt et al found 68% of identical twins share OCD as opposed to non identical- 31%
Studies suggest must be some genetic influence on development of OCD
Whats a limitation of genetic explanation of OCD
There environmental risk factors , contradicts genetic explanation even tho there’s evidence for genetic variation to make someone more/less vulnerable
Eg Cromer et al found over 1/2 OCD clients in sample had experienced traumatic event , + OCD more severe in those w one or more traumas
Genetic vulnerability only provides partial explanation for OCD
What is the neural explanation of OCD
-genes associated with OCD likely to affect levels of neurotransmitters + structure of brain
-physical + psychological traits determined by NS behaviour
What is the role of serotonin of the neural explanation
-Serotonin - help regulate mood
-(neurotransmitter role to relay into 1 neuron to another)
-if one has low levels of serotonin , then regular transmission of mood-relevant info X occur + can exp low mood
Whats the role of decision making systems in neural explanation
-Particularly hoarding disorder seem to be associated with impairment in lateral of frontal lobes of brain (responsible for logical thinking + decision-making) + said parahippocampal gyrus associated w/ processing unpleasant emotions, function abnormally in OCD
Whats a strength of neural explanation of OCD
Existence of supporting evidence
Antidepressants that work purely on serotonin = effective in reducing OCD symptoms + so may be involved in OCD
OCD symptoms form part of conditions that = biological in origin like Parkinson’s (muscle tremors) - Nestadt et al
If biological disorder produces OCD symptoms, we may assume the biological processes underlie OCD
Whats a limitation of neural explanation of OCD
Serotonin -OCD link may X be unique to OCD
Many ppl w OCD also experience clinical depression
2 disorders - co-morbidity
This depression prob involves disruption to action of serotonin -> logical problem when it comes to serotonin as possible basis for OCD
Could simply be that serotonin activity disrupted in many w OCD as are also depressed
Serotonin may X be relevant to OCD
