Possible content:

the role of neurochemicals such as serotonin and dopamine – levels associated with abnormal transmission of mood-related information/obsessive thoughts
structural deficits – abnormal functioning in the parahippocampal gyrus which processes unpleasant emotions; hyperactivity in the basal ganglia linked to repetitive actions (compulsions); the orbito-frontal cortex ‘the worry circuit’ – the caudate nucleus-thalamus loop, inability to filter small worries in OCD so worry circuit is overactive
damage to neural mechanisms due to breakdown of immune functioning, g. via Lyme’s disease.

Note: that genetic explanations alone should not be credited unless there is an explicit link made between genes and levels of neurotransmitter/structural deficits.

Possible evaluation points:

evidence to support/contradict the effects of neural mechanisms in OCD
success of drug treatments, g. SSRIs, suggests that low serotonin is a causal factor
not all patients respond to drug treatment which casts doubt on the explanation’s validity
issue of causation – neurochemical imbalances/structural abnormalities in the brain may be a symptom rather than the cause of the illness
many neural mechanisms have been identified but these are not always present in all cases
some studies of abnormal brain functioning, g. Aylward, have not been replicated
comparison with other explanations.

Credit other relevant material.

OCD (AQA A Level Psychology)

Topic Questions