Describe + evaluate the biological approach to OCD

• AO1- define OCD

  Anxiety disorder which is characterised by persistent, intrusive thoughts and repetitive behaviours
• AO1- OCD is inherited


  genetic explanation says mental illnesses are inherited

  developing OCD is higher for 1st degree relatives and the risk of inheriting is higher in some families than others
• AO1- candidate genes

  Genes that code for vulnerability to OCD

  OCD is polygenic (caused by many genes that increase vulnerability)

  A specific gene variation/group of genes may result in OCD for one person but not everyone with that genetic profile

  Dopamine and serotonin are neurotransmitters linked to mood, emotional and motivation
• AO1- COMT gene

  linked to OCD as it de-activates dopamine

  irregular dopamine levels are shown in OCD

  COMT gene helps balance dopamine levels

  COMT gene variation can contribute OCD as it helps control OCD
• AO1- SERT gene

  affect transport of serotonin

  lower levels of serotonin are shown in OCD

  help balance mood which can help regulate obsessive thoughts
• AO3- study Supporting genetic explanation to OCD

  A study showed 68% of monozygotic twins had OCD compared to dizygotic twins with 31%

  Increases validity as OCD can be explained by genetics
• AO3- twin studies

  each twin is the control for the other

  individual differences are accounted for

  large samples result to robust quantitative data increasing reliability
• AO3- biologically redutionist

  twins are grown in the same environment so they have the same upbringing and lifestyle, if the environment also contributes to OCD the genetic explanation can’t fully explain the development
• AO3- lack of understanding of genetic mechanisms

  even though there is a genetic explanation, there isn’t enough understanding of it

  lacks validity