EXPLAINING OCD

• WHAT METHOD IS USED TO EXPLAIN OCD?

  biological
• WHAT ARE THE TWO TYPES OF BIOLOGICAL EXPLANATIONS FOR OCD?

  genetic, neural
• WHAT TYPE OF CONDITION IS OCD?

  polygenic
• WHAT DOES THE GENETIC EXPLANATION SAY IS TO BLAME FOR OCD?

  mutated SERT and COMT genes
• WHAT DOES A SERT GENE MUTATION CAUSE?

  • increase in serotonin reabsorption
  • decrease in serotonin in synapse
• WHAT DOES A COMT GENE MUTATION CAUSE?

  • decrease in dopamine reabsorption
  • increase in dopamine in synapse
• WHAT DOES SEROTONIN DO?

  regulate mood
• WHAT DOES DOPAMINE DO?

  regulate concentration and motivation
• WHAT IS ANOTHER WORD FOR IDENTICAL TWINS?

  monozygotic
• WHAT IS ANOTHER WORD FOR FRATERNAL TWINS?

  dizygotic
• WHAT APPROACH MAY BE MORE APPROPRIATE THAN THE GENETIC APPROACH?

  psychodynamic
• WHAT DOES THE NEURAL EXPLANATION STATE THE LOW LEVELS OF SEROTONIN CAUSE?

  anxiety
• WHAT DOES THE NEURAL EXPLANATION STATE THE HIGH DOPAMINE CAUSES?

  • hypervigilance
  • concentration on threats
  • motivation to respond to obsessive thoughts with compulsive behaviour
• WHAT PART OF THE BRAIN IS INVOLVED IN DECISION MAKING AND REGULATION OF PRIMITIVE ASPECTS OF BEHAVIOUR?

  prefrontal cortex (PFC)
• WHAT DOES THE PFC CONTROL?

  decision making and regulation of primitive aspects
• WHAT DOES THE NEURAL EXPLANATION STATE ABOUT THE PFC?

  damaged = activates at inappropriate times (messages of safety not communicated correctly)
• EVALUATION OF GENETIC EXPLANATION?

  + research support

  -methodological issues

  -fails to consider trauma

  -limited explanation
• GENETIC EXPLANATION RESEARCH SUPPORT?

  Nestadt

  -> meta-analysis of twin studies

  -> 68% concordance rate for monozygotic twins

  -> 31% concordance rate for dizygotic twins
• METHODOLOGICAL ISSUES OF GENETIC EXPLANATION?

  • with family/ twin studies
  • same environment
• EVALUATION OF NEURAL EXPLANATION?

  + research support

  -low explanatory power
• RESEARCH SUPPORT OF NEURAL EXPLANATION?

  Soomro

  -> effect of SSRIs compared to a placebo at reducing symptoms

  Menzies

  -> abnormalities in PFC on fMRI scans of OCD patients
• LOW EXPLANATORY POWER OF NEURAL EXPLANATION?

  does OCD cause symptoms or is OCD caused by symptoms