Biological approach in explaining OCD Flashcards
Concordence rate
Define
Measure of genetic similarity.
Twin studies, if one twin has a phobic disorder there is a 40% chance that there twin will too.
Gene
Define
A part of a chromosome that carries information in the form of DNA
Neurotransmitter
Define
Chemical substances that play a key role in the owkrings of the nervous system by transmitting nerve impulses across the Synapse.
COMT gene
The comt gene produces enzymes which regualtes the production of dopamine.
One variation of the COMT gene has the effect as it has lower activity if the gene and high levels of dopamine- Tukel
The SERT gene
Affects the transports of seretonin, and this effects the formation of OCD.
High Dopamine+ low seretonin= OCD
Diathesis stress.
Some people have these genes, but it wont effect them until a stresser is active.
Abnormal levels of neurotransmitters
Neural explanations.
Dopamine levels are abnormally high in people with OCD as dopamine enhanced drugs showed OCD traits when tested on animals.
Antidepressents can increase Seretonin so reduce OCD symptoms.
Abnormal brain circuits
Neurakl explanations
Areas in the fron of the brain are seen to be abnormal in people with OCD, as the Caudate nucleus is damaged do it will send more worry signals to the thalamus.
Evalutation
Strength- Family and twin studies
Compared with non identical twins, identical twins are more than twice as likely to develop OCD if their twin has it- Billett.
Ocd is genetic, if your relative has it you will be 5x more likely to have it.
Evalutation
limitation-Tourettes syndrome and other dissorders
Pauls anf Leckman- argue that that OCD has the same genes as tourettes and other obsessive dissorders.
There is no one gene that links directly to OCD
Evaluation
Strength- reaserch supports genes
studies demonstrate a link with genetic abnormalities to low or high levels of neurotransmitters, compared to healthy people.
