Biological Approach to OCD

• nedstadt et al

  reviewed previous twin studies on OCD

  found that 68% of identical twins and 31% of non-identical twins experience OCD

  Suggests a very strong genetic component
• Counter argument

  No twin study has found a concordance rate of 100% in identical twins

  Which means biological factors are not the only factor contributing to OCD and there must be environmental factors
• Drugs used to affect serotonin such as SSRIs may decrease the symptom but that does not mean that there was ever an imbalance of serotonin in the first place

  Based on the assumption that there is a chemical imbalance

  Anti-depressants SSRIs - fluoxetine

  Selective serotonin reuptake inhibitor

  Anti-anxiety drugs - an alternative to SSRIs
• The genetic explanation for OCD

  • genes can cause an individual vulnerability to OCD
  • according to the diathesis-stress model, certain genes leave some people more likely to develop a mental disorder
  • some environmental stress is necessary to trigger the condition
• Candidate genes

  • researchers have identified candidate genes which create vulnerability to OCD
  • some of these genes are involved in regulating serotonin across synapses
• OCD is polygenic

  • caused by a combination of genetic variations
  • Research by Taylor: up to 230 different genes may be involved in OCD development