Summary Psychology- Biological Appraoch to Explaining OCD (AO1 & AO3)

the biological approach to explaining ocd (ao1)


Genetic Neural

genes hormones


Lewis (1936)
Out of 36 OCD patients
- 37% had parents with OCD
- 21% had siblings with OCD

OCD runs in families and individuals can inherit OCD through genetic vulnerability.

Candidate genes - makes an individual more vulnerable towards the onset to OCD
- 5HT1-D gene
- OCD is linked to a mutation in serotonin. This gene transports serotonin across the
synapses.

OCD is polygenic
OCD is caused by multiple candidate genes.
Not one single gene is linked to OCD.

Taylor (2013)
Up to 230 genes contribute towards OCD, these genes impact dopamine and serotonin
which are neurotransmitters affecting mood.

Diathesis Stress Model
Certain genes increase the likelihood of the onset of OCD, however life stresses trigger the
activation of these genes.
- SERT gene: lower levels of serotonin
- COMT gene: higher levels of dopamine

Life stresses: Unemployment, University, Break Up
- Can increase the onset of depression.

Types of OCD
Different genes will trigger different types of OCD
- E.g A hoarding OCD may be connected to heightened levels of dopamine.
- (Patient feels rewarded when they see more objects gathering).

Decision making systems
Some cases of OCD are linked to impaired decision making.
This turn may be associated with abnormal functioning of the lateral (side bits) of the frontal
lobes of the brain.
The frontal lobes are the front part of the brain that are responsible for logical thinking and
making decisions.