neural explanations of OCD

what is the neural explanations of OCD

focus in the role of key neurotransmitters and brain structures in causing OCD

if either of these have abnormalities, OCD may occur

what are the two neurotransmitters associated with OCD

serotonin

dopamine

interplay between these triggers OCD

low levels of serotonin

involved in creating repetitive thoughts and obsessions

high levels of dopamine

cause compulsive behaviours

What does OFC (orbitofrontal cortex) do?

decision making

OCD patients have higher activity in the OFC (PET scans)

overactivity in OFC

results in hyper-focused anticipation of negative consequences (obsessions)

what is the basal ganglia

cluster of neurones at base of forebrain linked to coordination og movement

trauma in basal ganglia

patients develop OCD-like symptoms, e.g. compulsions

reduces ablity to exert control over impulses- those experiencing OCD more likely to act on the heightened level of activity

strength of neural explanation- empirical support from neuroimaging studies

- Saxena (2000) used fMRI to show abnormal activity in specific brain regions of OCD patients

- identified increased activity in OFC and caudate nucleus- associated with decision making and habit formation

- hyperactivity linked to intrusive thoughts/compulsions which characterise OCD

strength of neural explanations of OCD- effectiveness of SSRIs

- success of SSRIs= strong evidence for role of neurochemistry

- Soomro (2008)- SSRIs more effective than placebos at reducing OCD symptoms- serotonin imbalance key factor

- increase serotonin levels in synaptic cleft, reducing compulsions

- not all patients respond to SSRIs- serotonin dysfunction not sole cause

- whilst neurochemistry important, other factors, e.g. cognitive/environmental elements, contribute to OCD

weakness of neural explanations- correlation doesn't mean causation

- correlational so difficult to establish causation

- studies like Saxena (2000) show abnormal brain activity in OCD patients, unclear if they are the cause or result of OCD

- increased activity in OFC may be due to engaging in repetitive compulsive behaviours, rather than cause of them

- ambiguities weaken explanation

weakness of neural explanations- reductionist perspective overlooks other factors

- simplifies OCD to genetic factors minimises role of environmental factors, e.g. trauma

- Cromer et al. - over half OCD patients had experienced trauma, highlights importance of non-genetic factors

- focus on genetics misses crucial aspects, limiting effectiveness of treatments

- other factors have role to play in developing OCD , e.g. learning, incomplete understanding of disorder