OCD Obsessive Compulsive Disorder

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OCD(Obsessive Compulsive Disorder)
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Summary of topics

• Introduction
• Links to other conditions
• Serotonin Basal Ganglia Hypothesis
• Basal Ganglia evidence
• Serotonin
• Evolutionary view
• Conclusion

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OCDIntroduction

• Obsessions thoughts (eg harming others)
• Recurrent, persistent and irrational impulses,
  thoughts or images that cause anxiety or distress
  and are not just excessive worries of real life
  (DSMIV)
• Compulsions actions (eg washing)
• Ritualistic, repetitive, purposeful behaviours or
  mental acts that an individual feels compelled to
  perform in response to an obsession (DSMIV)
• Also seen in other conditions

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Incidence

• Neurosis incidence about 2
• Typical onset young adulthood, but about 40 show
  childhood symptoms
• Average lifetime prevalence of 1-3 in adults
• More males than females in childhood
• 21 to 32 ratios
• Earlier age of onset for males
• Males have more severe symptoms
• More females than males in adults
• Cultural variations of OCD

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What tends to happen.

• The person attempts to ignore or suppress those
  impulses/thoughts/images or neutralise them with
  some other thought or action
• Interference with Normal Functioning
• Personal Distress
• Deviance from Social Norms
• The person recognizes that those are a product of
  their own mind i.e. neurosis rather than psychosis

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Patterns of behaviour

• Type of obsessions
• dirt and germs (40)
• Worries about something terrible happening (24)
• Worries about symmetry, order and exactness (17)
• Males high prevalence of checking
• Females high prevalence of washing

• Type of compulsions
• Excessive or ritualistic handwashing, bathing,
  showering, grooming (85)
• Repeating rituals, e.g., going in or out of a
  door (51)
• checking compulsions gas, locks (46)
• Ordering or arranging (17)
• Counting (18)
• Hoarding or collecting old newspapers, empty
  boxes (6)

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OCDlinks

• Family (genetic?) association with Tourettess
• Depression and anxiety common about 50 is
  psychological response to OCD
• Anorexia epilepsy
• Sydenhams chorea (about 30 have OCD)
• Post-encephalitic Parkinsonism
• Post-partum mothers

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OCD Serotonin Basal Ganglia Hypothesis

• OCD result of Malfunctioning instinct-related
  system
• Basal Ganglia, especially Caudate nucleus
• Serotonin key transmitter (in this system,
  serotonin seems to balance dopamine)
• OCD helped by raising 5-HT (shorthand for
  serotonin) levels

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OCD Basal Ganglia cont.

• Poisoning/stroke etc. can cause OCD
• Parkinsons, Sydenhams, Tourettes
• Stroke to Caudate nucleus or to cingulate gyrus
  or frontal cortex can gt OCD
• PET shows bilateral Caudate and left orbital
  gyrus are over active
• rCBF shows right caudate, left anterior cingulate
  gyrus and bilateral orbital area

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OCD Basal Ganlia cont

• Worst 35 OCD helped by bilateral
  cingulotomy/cingulectomy. This Disconnects the
  cingulate cortex from the orbitofrontal areas
• Insel (1992) proposed a model of the system
  frontal-striatal-thalamic loop
• Cingulate cortex part of emotional systems i.e.
  the limbic system

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OCD Serotonin

• Only effective drugs are SSRIs (serotonin
  specific reuptake inhibitors)
• Clomipramine first (still seems best), Prozac
  (fluoxetine)
• 5-HT agonists worsen OCD
• But SSRIs take 2-3 weeks for clinical effect,
  but the effects occur sooner.
• Da (Dopamine) and 5-HT seem to balance in Caudate

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OCD Evolutionary view

• Key ancient, species specific fixed action
  patterns (FAPs) e.g. grooming are being triggered
  inappropriately
• Hormonal cycles in adult females influcence
  severity. Post-partum cases (Fits FAPs)
• 5-HT influences FAPs etc. in mammals
• Basal Ganglia mediate FAPs in manny mammals
• Just exaggerated normal behaviour??

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OCD Conclusion

• Biological basis plausible
• Behaviour therapy shows learning is crucial.
  Could work on links between FAPs and
  environmental triggers?
• Links to the will see also Parkinsons and
  really knowing
• Shows the value of multiple perspectives