biological explanations & treatments for OCD

• Genetic explanation:

  • people inherit OCD
  • Lewis (1936): 37% of patients = parents with OCD; 21% of patients = siblings with OCD
• Diathesis-stress model: if someone with a vulnerability to OCD goes through a negative/traumatic event, OCD is likely to onset.
• Candidate genes involved in OCD:

  • COMT: dopamine gene, if someone has too much of this they will have too much dopamine. This increases likelihood of OCD & anxiety.
  • SERT: decreases levels of serotonin by affecting the transportation of it.
  • Taylor (2013): OCD is polygenic so several genes influence it. Around 230 genes influence the likelihood of someone having OCD.
• Aetiologically heterogeneous: origins of OCD differ in all people.
• Neural explanation:

  • people with OCD have low levels of serotonin. Cannot regulate their mood.
  • people with OCD have impaired decision making systems. Lateral parts of the frontal lobe and left parahippocampal gyrus (processes unpleasant emotions) are impaired.
• Drug treatments:

  • SSRIs are used to treat OCD. They prevent the break-down of serotonin in the synapse which makes the body think there is more serotonin than there actually is. This then helps people with OCD regulate and increase their mood.
  • there are different types of SSRIs, one being fluoxetine (prozac). This has they typical dose of 20mg but can be increased; clients have to take this drug for 3-4 months before it starts to work.
  • are alternatives to SSRIs: SNRIs & tricyclics.
• Genetic explanation - AO3:

  • research support: Nestadt et al (2010). 68% of MZ twins both have OCD; 31% of DZ twins both have OCD. Validates the explanation.
  • environmental factors may influence OCD. Cromer (2007) most OCD patients had a negative/traumatic experience. The genetic explanation is partial.
• Neural explanation - AO3:

  • supporting evidence. Antidepressants have been found to decrease OCD symptoms. Supports that serotonin has a role in OCD. Increases the validity of the explanation.
  • link to serotonin may not be as significant as originally thought. Some OCD patients also have depression, which is linked to low serotonin levels. Serotonin levels might be low in people with OCD because of depression. Decreases the validity.
• Drug therapy - AO3:

  • research support: Soomro et al (2009) people who had SSRIs = 70% decrease in OCD symptoms. D: research found that CBT is more effective than SSRIs. But, SSRIs have been proven effective.
  • cost & time effective. SSIs are cheaper and easier that other treatment options for OCD.
  • side effects. Some people on drug treatments experience side effects that influence their life e.g., blurry vision. People might stop taking the drugs because of this which decreases the effectiveness of them.