biological approach to explaining ocd

• Gene


  The biological unit of heredity
• The biological approach to explaining OCD
• Genetic explanations


  • The COMT gene
  • The SERT gene
  • Diathesis-stress
• Diathesis-stress


  A model that suggests a genetic predisposition (diathesis) interacts with life stressors to produce a disorder
• Abnormal levels of neurotransmitters, particularly serotonin, are associated with OCD
• Serotonin reuptake inhibitors (SSRIs) that have less serotonin activity are effective treatments for OCD
• Neural explanations for OCD

  • Abnormal brain circuits
  • Abnormal levels of certain neurotransmitters
• Brain circuits involved in OCD

  1. Signals from the orbitofrontal cortex (OFC) to the thalamus about things that are worrying

  2. Caudate nucleus fails to suppress the worry signals

  3. Signals bounce back to the OFC, acting as a loop
• PET scans of patients with OCD show heightened activity in the frontal lobes when experiencing symptoms
• The caudate nucleus plays a key role in the connection of the OFC and the caudate nuclei, and its dysfunction may cause these areas to malfunction
• High levels of dopamine lead to overactivity of this neural circuit