A01

• introduction 


  OCD is characterised by obsessions and compulsions which can be explained biologically. The biological approach in general focuses on how the physical internal factors of our body can explain behaviour. 
• Genetic explanations


  OCD is a polygenetic condition involving over 230 genes
• Genetic explanations


  • Proposes the presence of candidate genes involved in the development of OCD
  • mutations in:
  • COMT gene regulates the production of dopamine (one version increases dopamine production, leading to positive feelings when responding to obsessions which increases the continuation of compulsions)
  • SERT gene is involved in regulating serotonin (may be responsible for higher levels of anxiety due to low serotonin and therefore increased obsessions)
• neural explanations 


  There are also neural explanations of ocd, including the levels of neurotransmitters dopamine(high) and serotonin (Low), which are associated with mood regulation.
• second neural explanation

  •  abnormal brain circuits, researchers found hypersensitivity of the basal ganglia gives rise to repetitive motions as seen in ocd, in addition to this, abnormal functioning/overactivity in the orbital frontal cortex leads to impaired decision making associated with ocd along with increased anxiety.
  • Finally, an overactive thalamus would result in an increased motivation to clean or check for safety.