OCD Biological explanations

Certain genes create a vulnerability to OCD; these are called candidate genes.

• serotonin
• dopamine

OCD is polygenic, I.e. Not one but a group of genes is involved.

OCD is aetiologically heterogeneous, meaning that different variations of genes cause OCD in different people.

Neurotransmitters are responsible for passing info to neurons.
Low-levels of serotonin are associated with a low mood.

Some OCD is associated with impaired decision making. This may be due to abnormality in the frontal lobes. This is responsible for logical thinking and decision making.

The parahippocampus gyrus may be dysfunctional - this is associated with processing unpleasant emotions.