Psychopathology - Genetic Explanations for OCD Flashcards
Concordance rate
A measure of genetic similarity
Neurotransmitter
A chemical that transmits impulses across a synapse
Gene
Part of chromosome that carries information in form of DNA
Dopamine
Key neurotransmitter in the brain which effects motivation and drive
Serotonin
Neurotransmitter which regulates mood
Diathesis stress model
Particular gene may predispose you to get particular disorder but it had to be triggered by environmental factor
Biological, genetic explanation for OCD
Inherited from your parents via genes
Biological, neural explanation for OCD
Certain neurotransmitters and structures of the brain are concerned with OCD
What has been implicated as a possible cause for OCD?
A number of candidate genes
What is a candidate gene?
A potential gene that may be responsible
How did Taylor find out that OCD is polygenic?
He identified up to 230 candidate genes for OCD
What does the COMT gene help to reduce?
Action of dopamine
What is the COMT gene associated with?
Production of an enzyme which regulates function of dopamine
What does a variation in the COMT gene decrease the amount of?
COMT available meaning dopamine isn’t controlled meaning there will probably be too much dopamine
What is gene variation more common in?
Patients with OCD
What did the COMT gene do in individuals with OCD?
Mutate
What does the SERT gene do?
Affects transport of serotonin
What does the SERT gene create?
Low levels of serotonin
What have low levels of serotonin been implicated with?
OCD
What does mutation of SERT Gene cause?
Increase in transporter proteins at a neuron’s membrane
What does an increase in transporter proteins result in?
Less binding resulting in lower amounts of serotonin
What is a meta-analysis?
A study combining results of lots of studies
What did Billett et al carry out?
A meta-analysis of 14 twin studies
What did Billett find?
On average, MZ twins are twice as likely to develop OCD than DZ twins
OCD is polygenic
It isn’t caused by a single gene
What is a reduction of dopamine levels positively correlated to?
The reduction of OCD symptoms
What don’t genes determine?
Who will develop OCD - they only create vulnerability
What shows OCD is due to interaction of genetic and other factors?
Evidence shows concordance rates aren’t 100%
How may OCD be culturally transmitted?
Due to observed and replicated behaviours
