The biological approach to explaining OCD Flashcards
What are the 2 types of OCD explanation?
Neural and genetic
What 2 genes may contribute to OCD?
The COMT gene and the SERT gene
What does the COMT gene do?
Regulates the production of a neurotransmitter called dopamine
What is a neurotransmitter?
A chemical substance that transmits nerve impulses across a synapse
What is dopamine?
A neurotransmitter involved with motivation and ‘drive’
How is the COMT gene linked to OCD?
One allele of the gene is more common in OCD patients than people without the disorder
How does the OCD variation of the COMT gene lead to OCD symptoms?
It produces lower activity of the COMT gene and higher levels of dopamine
What does the SERT gene do?
Affects the transportation of serotonin
What does SERT do to serotonin levels?
Decreases them
What did a study regarding the SERT gene find?
In two unrelated families who had a mutated SERT gene, 6 of the 7 family members had OCD
In OCD patients, what are dopamine levels expected to be?
Higher than normal
What did animal studies find about dopamine?
High doses of drugs that enhance dopamine levels induce stereotyped movements resembling the compulsions of OCD patients
What is the name of the brain circuit associated with OCD?
The worry circuit
What are the 3 brain structures involved in the worry circuit?
The caudate nucleus, the OFC and the thalamus
What does the caudate nucleus do in an individual without OCD?
Supresses signals from the orbitofrontal cortex