Genetic explanation for oCD:

• STRENGTH:

  • strong evidence base
  • Evidence from a variety of sources which strongly suggests that some people are vulnerable to OCD as a result of their genetic make-up
  • Twin studies Nestadt et al 2010 reviewed twin studies, found 68% of identical twins (MZ) shared OCD as opposed to 31% of non-identical (DZ) twins

  These research studies suggest that there must be some genetic influence on the development of OCD
• LIMITATION:

  • there are also environmental risk factors
  • There is strong evidence for the idea that genetic variation can make a person more or less vulnerable to OCD
  • However, OCD does not appear to be entirely genetic in origin and it seems that environmental risk factors can also trigger or increase the risk of developing OCD
  • IE Cromer et al 2007 found that over half the OCD clients in their sample had experienced a traumatic event in their past
  • OCD was also more severe in those with one or more traumas

  This means that genetic vulnerability only provides a partial explanation for OCD