Neural explanations for OCD

• The genes associated with OCD are likely to affect the levels of key neurotransmitters as well as structures of the brain
• One explanation for OCD concerns the role of serotonin, believed to help regulate mood
• What happens if a person has low levels of serotonin?

  Normal transmission of mood-relevant information doesn't take place and a person may experience low moods
• Some cases of OCD may be explained by a reduction in the functioning of the serotonin system in the brain
• Some cases of OCD are associated with impaired decision making
• What is impaired decision-making associated with?

  Abnormal functioning of the lateral of the frontal lobes of the brain
• What are the frontal lobes responsible for?

  Logical thinking and making decisions
• What area of the brain is there evidence to suggest functions abnormally in OCD?

  The left parahippocampal gyrus
• What is the left parahippocampal gyrus associated with?

  Processing unpleasant emotions
• Regions of the brain responsible in OCD

  A) Parahippocampal gyrus

  B) Lateral frontal lobes

  
• Strength: Neural model of OCD

  What? Research support

  Who? Antidepressants effective in reducing OCD - suggesting serotonin may be involved in OCD

  OCD symptoms form part of biological conditions (i.e. Parkinson's) - suggests biological processes underlie OCD

  Why? Biological factors responsible for OCD
• Limitation: Neural model of OCD

  What? Serotonin-OCD link not unique to OCD

  Who? Many people with OCD also experience clinical depression (co-morbidity) - suggests serotonin activity disrupted in people w/ OCD because they're depressed too

  Why? Serotonin may not be relevant to OCD symptoms