Biological approach to explaining OCD

• What is genetic vulnerability for explaining OCD (genetic explanation)

  people genetically predisposed to OCD, candidate genes (5-HT1-D beta gene) affects transport of serotonin, low serotonin means low mood
• OCD as polygenic for explaining depression (genetic explantion)

  Not caused by one gene but combination that increases vulnerability, found 230 genes involved in OCD often linked to serotonin.
• OCD as aeteologically heterogeneous for explaining depression (genetic explanation)

  Origin varies by person, one group of genes causes OCD in person A but another group causes it in person B
• What is serotonin for explaining OCD (neural factors) 


  Neurotransmitter for mood, low serotonin means low mood which can explain some OCD forms
• What is the frontal lobe as an explanation for explaining OCD (structural factor)

  brain scans show activity levels, people with hoarding disorder have more activity at frontal lobe which controls decision making > impaired decision making
• what is a strength of the genetic explanation for explaining OCD

  Research support twin study found 68% of identical twins where one had OCD the other had OCD, 31% of non identical twins where one had OCD the other had OCD. Shows genetics play a role
• What is a weakness of the genetic explanation for explaining OCD

  Methodological limitation for twin studies - identical twins experience life very similarly. suggests also an environmental factor as well as genetic.
• What is a weakness of the genetic explanation for explaining OCD

  Diathesis stress model = more likely that genetic vulnerability is inherited rather than a certainty/ vulnerability combined with stress causes OCD, interactional appraoch
• What is a strength for neural factors as an explanation for OCD

  Research support, participants given serotonin drugs and it was found it reduced low mood symptoms
• What is a weakness of neural factors for explaining OCD

  Not Unique, many OCD patients also have depression, serotonin not exclusive to OCD
• What is a weakness of structural explanation for explaining OCD

  Correlation not causation issue, not necessarily activity levels causes OCD, could be obsessing about hoarding increased activity in frontal lobes