Evaluation of bio explaining OCD

• Evaluation of the biological approach to EXPLAINING OCD?

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  A) ?

  
• Evaluation of the neural approach to explaining OCD?

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  A) ?

  
• Evaluation of the genetic approach to explaining OCD

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  A) ?

  
• There is supporting evidence for some neural explanations of OCD

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  A) ?

  
• Supporting evidence for genetic explanations of OCD - biological approach of explaining OCD A03


  P: Supporting evidence from a variety of sources which suggest that some people are vulnerable to OCD as a result of their genetic make-up

  E: For example, Nestadt et al (2010) reviewed twin studies and found that 68% of identical twins (MS) shared OCD as opposed to 31% of non-identical (DZ) twins

  L: This strongly supports a genetic influence on OCD - but not fully genetic because not 100%. More evidence given by Marini & Stebruicki
• Limitation is too many candidate genes have been identified - biological approach of explaining OCD A03




  P: Twins studies suggest that OCD is largely genetic, but psychologists have been less successful at pinning down all the genes involved.

  E: One reason for this is that it appears that several genes are involved and that each genetic variation only increases the risk of OCD by a fraction. Taylor: 230 candidate genes

  L: Consequence is that a genetic explanation is unlikely to ever be very useful because it provides little predictive accuracy/value. Reducing its predictive validity
• Limitation is env risk factors are also involved - biological approach of explaining OCD A03



  P: Approach does not rake into account env risk factors - It is not just genes but it seems that environmental risk factors can also trigger or increase the risk of developing OCD.

  E: E.G, Cromer et al (2007) found over half OCD patients in sample had a traumatic event in their past, and OCD was more severe in those with one or more traumas

  L: This supports the diathesis-stress model. Focusing on environmental causes may be more productive because we are more able to do something about these
• Evidence supporting neural explanations of OCD - biological approach of explaining OCD A03

- PART 1


  P: Evidence to support role of some neural mechanisms in OCD

  E: E.G. some antidepressants work purely on serotonin system, increasing levels of the neurotransmitter, which effective in reducing OCD symptoms & suggests serotonin system may be involved in OCD

  E: Also OCD symptoms form part of a number of conditions that are biological in origin e.g. Parkinsons (Nestasdt et al 2010)
• Evidence supporting neural explanations of OCD - biological approach of explaining OCD A03

- PART 2


  L: Suggests biological processes that cause symptoms in those conditions may be responsible for OCD & it further supports the use of biological treatments.
• Limitation = Serotonin-OCD link may not be unique to OCD - BAtEOCD A03


  P: Many people who suffer from OCD become clinically depressed having 2 disorders together = co-morbidity

  E: Depression involves (not necessarily caused by) disruption to serotonin system disrupting action of serotonin. This leads to disrupted serotonin in people with OCD. This leaves us with logical problem when it comes to serotonin system as a possible basis for OCD.

  L: Could simply be that serotonin system is disrupted in many patients with OCD coz they depressed too. Don't know cause / effect of OCD
• Not clear what neural mechanisms are involved

  Other systems may be involved - we don't truly understand it

  So many disorders so much research needed to do on it
• Evaluation of The Biological Approach to explaining OCD A03



  • Genetic Explanations to explaining OCD:
  • -Env risk factors also involved (Cromer et al 2007)
  • -Too many candidate genes have been identified (Taylor)
  • +Supporting evidence for genetic explanations of OCD (Nestadt et al 2010 and Marini & Stebruicki)
  • Neural Explanations to explaining OCD:
  • +Evidence supporting neural explanations of OCD (Nestadt et al 2010)
  • -Serotonin-OCD link may not be unique to OCD
  • -Not clear what neural mechanisms are involved