Biological approach to explaining OCD

• What are candidate genes in relation to OCD?

  Specific genes creating vulnerability for OCD
• What role does the serotonin gene SHT1-D beta play in OCD?

  It is implicated in serotonin transmission
• Which neurotransmitters are implicated in OCD?

  Serotonin and dopamine
• How is OCD described in terms of genetics?

  OCD is polygenic, involving several genes
• What does aetiologically heterogeneous mean in the context of OCD?

  Different genes may cause OCD in different people
• What are some genetic variations that may result in OCD?

  Hoarding disorder and religious obsession
• What is the effect of low levels of serotonin on mood?

  It lowers mood and affects information transmission
• What is the role of neurotransmitters in the brain?

  They relay information between neurons
• How does low serotonin affect decision-making?

  It impairs decision-making systems in the frontal lobes
• Which part of the brain is associated with logical thinking?

  The frontal lobes
• What dysfunction is associated with the parahippocampal gyrus in OCD?

  It processes unpleasant emotions abnormally
• What do twin studies suggest about OCD?

  OCD is largely genetic due to several genes
• What is co-morbidity in relation to OCD?

  Presence of multiple disorders like depression
• How can depression affect serotonin levels in OCD?

  Depression can disrupt serotonin transmission
• What is the role of serotonin in OCD treatment?

  Serotonin may be involved in OCD symptoms
• What biological processes are responsible for OCD?

  Neurotransmitter imbalances and brain dysfunctions
• how many people does OCD affect /50

  1/50 people
• what two behaviours cause anxiety in someone with OCD

  • obsessive thoughts
  • compulsive behaviours
• how many candidate genes are inherited from parents?

  230
• what four genes are included in the 230 candidate genes ?

  1. SERT gene
  2. gene 9
  3. COMT gene
  4. 5HT1-D beta gene
• is OCD polygenic?

  yes
• what are neurotransmitters

  chemicals that cmmunicate information between neurons and laege structures in the brain
• what can low serotonin cause in OCD

  obsessive thoughts
• what does the orbitofrontal cortex do?

  makes rationa decion making
• what does the basal ganglia do?

  filters out minor worries
• what happens if the basal ganglia is hyperactive?

  small worries may get to the thalamus, which is passed back to the OFC where recurring obsessive thoughts occur
• what does the worry circuit consist of? (4 things in the brain)

  1. orbitofrontal cortex (OFC)
  2. basal ganglia
  3. nucleus
  4. thalamus
• what are repetive motor functions an attempt to do?

  to break the loop of reccurng obsessive thoughts
• if the compulsions carried out, it may give temporary relief- what may resume the worry circuit?

  hyperactive basal ganglia
• is the parahippocamalgyrus also linked to OCD?

  yes
• what is the parahippocampalgyrus responsible for?

  regulating and processing unpleasant emotions