genetic explanation for OCD

• Nestadt Et Al research

  One strength of the genetic explanation for OCD is the strong evidence base.

  There is evidence from a variety of sources which strongly suggests that some people are vulnerable to OCD as a result of their genetic make-up. One source of evidence is twin studies. In one study Gerald Nestadt et al. (2010) reviewed twin studies and found that 68% of identical twins (MZ) shared OCD as opposed to 31% of non-identical (DZ) twins. Another source of evidence for a genetic influence on OCD is family studies. Research has found that a person with a family member diagnosed with OCD is around four times as likely to develop it as someone without (Marini and Stebnicki 2012).

  These research studies suggest that there must be some genetic influence on the development of OCD.
• Environmental risk factors

  One limitation of the genetic model of OCD is that 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. In one study for example, Kiara 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.