Lesson 12: The biogical approach to explaining OCD Flashcards
What is OCD? (AO1)
An anxiety disorder characterised by the DSMV as when a patient shows REPETITIVE behaviour and OBSESSIVE thinking
What does the biological approach to explaining to OCD assume?
Assumes OCD is caused by GENETICS and NEURAL explanations (e.g neurotransmitters and ABNORMAL brain circuits)
Refering to genes, what is OCD classed as?
POLYGENIC- whereby MULTIPLE GENES are responsible for the development of OCD
How many genes are potentially responsible for causing OCD and what are these referred to as?
230- candidate genes
What are the TWO genes responsible for causing OCD.
COMT & SERT
How does the COMT gene have a role in causing OCD?
(COMT is highly DOPE)
1)COMT regulates the production of a neurotransmitter called DOPAMINE-> which in HIGH levels is associated with OCD.
HIGH DOPAMINE= drive, motivation and AGGRESSION
COMT GENE has been found to be more common in OCD patients than in people who do not have the disorder.
How does the SERT gene have a role in causing OCD?
this gene affects the TRANSPORTATION of SEROTONIN -> causing low levels of serotonin
Low levels=OCD & depression
Outline the research Ozaki (2003) did into OCD + the SERT gene
(hint: mutation)
-found 6 out of 7 family members who had OCD had a MUTATION on the SERT gene
-gene mutates which causes LOW levels of serotonin to be produced
-link between SERT gene and OCD
State a POSITIVE evaluation of the genetic explanation of OCD
(hint: first degree relative)
Nestadt (2000) SUPPORTS the genetic explanation for OCD.
He found that people who had a FIRST degree RELATIVE who already had OCD were 5x more likely to GET the disorder
State a POSITIVE evaluation of the genetic explanation of OCD
(hint: Mz twins vs Dz twins)
Billett supports the idea that OCD is transmitted GENETICALLY
He found from a meta-analysis of 14 twin studies that OCD is 2x as likely to be CONCORDANT in IDENTICAL (monozygotic twins) than NON-IDENTICAL (dizygotic) twins
State a NEGATIVE evaluation of the genetic explanation of OCD
(hint: concordance rate does NOT = 100%)
A criticism of the genetic explanation is that the CONCORDANCE rate for OCD in identical twins is not 100%
Therefore OCD cannot be CAUSED entirely by genetics
State a NEGATIVE evaluation of the genetic explanation of OCD
(hint: behavioural approach)
The BEHAVIOURAL approach would CONTRADICT the genetic explanation for OCD.
the two process model would suggest
OCD= learnt via classical conditioning
+maintained through OPERANT conditioning
The behavioural approach has received a great deal of SUPPORT in explaining OCD and has led to the emergence of many BEHAVIOURAL THERAPIES to treat OCD e.g exposure
State a NEGATIVE evaluation of the genetic explanation of OCD
(hint: diathesis stress model)
diathesis stress model would argue that OCD can be caused by a COMBINATION of genes + trigger in the environment (stress)
THEREFORE, genes ALONE cannot be the ONLY cause of OCD; genes would need to be combined with other factors in order for the DISORDER to develop
(Neural explanations)
What are the TWO neurotransmitters that affect mood
Dopamine and Serotonin
What have abnormal levels of dopamine + serotonin been associated with?
Abnormal transmission of MOOD related information
What neurotransmitter do individuals suffering with OCD have high levels of?
HIGH levels of DOPAMINE
What part of the brain have high levels of dopamine been linked with?
HYPERACTIVITY in the BASAL GANGLIA area in the brain
What does hyperactivity in the basal ganglia cause
Repetitive motor functions (e.g COMPULSIONS)
What neurotransmitter do OCD sufferers have LOW levels of?
SEROTONIN
What part of the brain does serotonin operate?
Operates the CAUDATE nucleus in the brain
What does low levels of serotonin cause the caudate nucleus to do?
Causes it to malfunction
What is the caudate nucleus responsible for?
plays a VITAL role in how the brain learns-> STORING and PROCESSING of memories
-it works as a FEEDBACK processor which means it uses information from PAST experiences to influence future actions + decisions
State a POSITIVE evaluation of neural explanations of OCD
(hint: anti-depressant drugs)
There has been a GREAT DEAL of research to support the idea that neurotransmitters do cause OCD
ANTI DEPRESSANT DRUGS will increase serotonin in OCD patients which has led to a REDUCTION of OCD symptoms
therefore->good evidence to suggest that low levels of serotonin could be a cause for OCD
State a POSITIVE evaluation of neural explanations of OCD
(hint: risperidone + dopamine)
Research by CICCERONE(2000) would support NEURAL explanations of OCD.
He found giving OCD patients low doses of the drug RISPERIDONE helped lower DOPAMINE levels + alleviate symptoms of OCD.
high levels of dopamine= cause OCD
State a NEGATIVE evaluation of neural explanations of OCD
(hint: co-morbidity)
A problem with neural explanations is that OCD is co-morbid with depression.
Therefore, it is not CLEAR whether low levels of serotonin cause OCD, depression or BOTH.
The direct link between serotonin levels and OCD is not clear + needs to be investigated further
State a NEGATIVE evaluation of neural explanations of OCD
(hint: cause and effect)
neurotransmitters like dopamine and serotonin may not necessarily CAUSE OCD.
instead they may be the EFFECT of OCD.
Therefore, cause and effect must be established
