psychopathology

• The COMT gene is associated with the production of dopamine
• Genetic explanations suggest OCD is inherited and that individuals inherit specific genes which cause OCD
• 2 genes have been linked to OCD, including the COMT gene and SERT gene.
•  One variation of the COMT gene results in higher levels of dopamine and this variation is more common in patients with OCD
•  The SERT gene is linked to the neurotransmitter serotonin and affects the transport of the serotonin (hence SERotonin Transporter), causing lower levels of serotonin which is also associated with OCD and depression
• Neural explanations of OCD focus on neurotransmitters as well as brain structures
• Neural explanations suggest that abnormal levels of neurotransmitters, in particular serotonin and dopamine, are implicated in OCD
• Neural explanations also suggest that particular regions of the brain, in particular the basal ganglia and orbitofrontal cortex, are implicated in OCD.
• Some cases of OCD are also associated with the reduced levels of serotonin, which may be caused by the SERT gene 
• Support for the role of serotonin in OCD comes from research, where we have found that the increase of the level of serotonin is effective in treating patients with OCD.
• Limitation - ignores other factors and is reductionist
• biological approach to OCD doesn't take into account cognitions (thinking).
•  Lewis (1936) examined patients with OCD and found that 37% of the patients with OCD had parents with the disorder and 21% had siblings who suffered.