Psychopathology - biological approach to EXPLAINING OCD Flashcards
What are the 2 forms of explanaitons
neural
genetic
genes are involved in indiviudal vulnerability to
OCD
what are gentic explantions of ocd
2 points
suggest….
Genetic explanations suggest OCD is inherited and
individuals inherit specific genes which cause OCD
what study shows us genes invlved ing enetic vulerability of OCD
Lewis observed of his ocd patients
37% got parents with OCD
21% got siblings with OCD
what does LEwis study obsv of ocd in his patients suggest
OCD runs in families
but whats porbably passed on from one gen to next
is genetic vulneerabliry not cetainity of OCD
according to diathesis stress model for OCD
certain genes
leave some people more likely to developn a menal disorder
but its not certain
some environmentla stress(experience) is necessary to trigger condition
what are candidiate genes in terms of OCD
particular genes which create a vulnrabiity for OCD
What are candiate gens inovled in in terms of ocd
regulaitng the development of serotinin systems
What are candiate gens inovled in in terms of ocd
+ give an example
some involved in regulating development of serotonin
e.g gene 5HT1-D beta is implicated in transport of serotinin across syanpses
OCD is a certain type of adjective used to descire genes
polygenic
OCD is a certain type of adjective used to descire genes
polygenic
ocd being polygenic means
ocd is caused by a combo of genes that together significantly increase vulnerability
rather than one single gene
OCD POLYGENIC - taylor analsyed
findings of previosu studes
OCD POLYGENIC - taylor analysed findings of previosu studies what did he find
eviednce up to 230 differnet genes may be involved with OCD
OCD POLYGENIC - Genes studied in relation to OCD include
those assocaited with actions of dopmaine and serotonin
SERT and COMT
OCD POLYGENIC - whihc neurtotransmitters are believed to ahve a role in regulaitng mood
dopamine and setotoning
different types of OCD - one group of genes may cause OCD in one person but a differnt …
but a differnt group of genes may cause disorder in another person
different types of OCD - what is aetiologically heterogeneous
origins of OCD vary from one person another
different types of OCD - theres is evidence to sugets different types of OCD may be the result of
particular genetic variations
e.g hoarding disorder
religious obsession
what are neural explanaitons
Neural explanations of OCD focus on neurotransmitters as well as brain structures.
ROLE OF SEROTININ - one explantion for OCD concerns the roel of neurotransmitter
serotonin
ROLE OF SEROTININ - what is serotonin belived to do
help regulate mood
ROLE OF SEROTININ - neurotransmitters are responsible for
relaying info from one neuron to another
ROLE OF SEROTININ - if a person ha slow levels of setotinin what happens
normal transmission of mood relelvant info dont take place and a person may xp low moods
+ othe rmentla processes may be affected
ROLE OF SEROTININ - at least some cases of OCD may be explained by
reduciton in functioning of serotinin system in the brain
DECISION MAKING SYSTEMS - some cases of OCD in particular hoarding disorder seem to be associaed with
impaired descison making
DECISION MAKING SYSTEMS - impaired descisoin making may be associated with
abnormal functioning of the lateral of the frontal lobes of the brain
DECISION MAKING SYSTEMS - what does lateral mean
side bits
DECISION MAKING SYSTEMS - the frontal lobes of the brian are hte which part of your brian
front part of brain behind your forehead
DECISION MAKING SYSTEMS - frontal lobes are resposbible for
logical thinking and making descisions
DECISION MAKING SYSTEMS - theres also evidence to suggest the left parrahippocampal gyrus which is associated with :
functions …
processing unpleasant emotions
functions abnormally in OCD
STRENGHT - SUPPORTING EVIDENCE FOR GENES
hay evidence from variety of sources for the idea people are vulnerable to OCD as a result of their genetic make up
one of best sources of evidence for importance of genes is twin studies
nestadt et al reviewed previosu twin studies and found 68% of identical twins shared OCD as opposed to 31% of non identical twins
this strongly suggests a geentic influcne on ocd
SUPPORTING EVIDENCE FOR ENVIRONMENTLA RISK FACTORS - genes - can be limitaiton if dont mention diathesis stress
research support for impact f enviro factors that can act as trigger or increase risk of developing OCD
e.g researcehrs found over half of OCD patients in sample ahd traumatic event in oast
and cod was more severe in patitents with more than one truama
suggests ocd may not be entirley genetic in orging or at least not in all cases
may therfore be more productive to focsu on enviro causes as were more able to do something about theses
LIMIATION OF NEURAL EXPLANATION - issues of causation
theres issue with understanding neural mechanisms involved in OCD
While thres evidence which suggests certain neural systems dont function normally in patients suffering from OCD e.g orbifrontal cortex
research has also identified other areas in the brain that are occasionally involved as well
this means theres no brian system whihc has consistently been found to play a role in OCD
So although tehrees evidence that neuro transmitters and brian structures are implicated , it must not be concluded there is a casue and effect relationship
as its difficult to ascertain whether the biological abnormalitiies seen are a casue of OCD or result of the disorder
strength of neural explanation
supporting evidence for role of some neural mechansims in OCD
e.g antidepressants that work purely on serotonin system increasing elvel of this neurotransmitter are effective in reducing OCD symptoms and this suggests that the serotonin system may be involved in OCD
also OCD symptoms form part of biological conditions such as parkinsons disease
this therfore suggets that the biological processes taht cause symptoms in those conditions may also be responsbile for OCD
