OCD

• characterised by obsessions and compulsions
• Obsessions


  recurrent unwanted thoughts
• Compulsions


  repetitive behaviours/mental acts
• Obsessions


  Recurrent unwanted thoughts
• Compulsions


  Repetitive behaviors or mental acts often performed in response to obsessions, typically with the goal of reducing anxiety and discomfort
• OCD is often very distressing, and is not just a preference for orderliness, as the term is sometimes used to imply
• The neuroscience of OCD is not completely understood, and it's likely that different neural circuits may be involved based on a person's age and symptom profile, among other factors
• One supported perspective on the neuroscience of OCD


  • Prominent role for circuits that connect the orbitofrontal cortex with a group of structures called the basal ganglia
  • Increased activity in the orbitofrontal cortex is associated with a heightened focus on concerns that spawn obsessive thoughts
• Basal ganglia circuitry


  1. Excitatory direct pathway

  2. Inhibitory indirect pathway
• When the orbitofrontal cortex sends a signal to the basal ganglia


  It often leads to an action designed to alleviate the discomfort caused by the perceived danger, mediated by the direct pathway
• In someone with OCD


  The direct pathway is over-excitable, drowning out the activity of the indirect pathway and causing a difficult time switching to a different behavior or turning focus away from the concern causing the discomfort
• According to this model, overactivity in the orbitofrontal cortex and the direct pathway of the basal ganglia increases the occurrence of both obsessions and compulsions