Updated for 1999
Lecture Notes - Week 14
Chapter 18
PANIC DISORDER
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1-2% of population
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2:1 female to male ratio
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usually starts in young adulthood; rare onset after age 35
anticipatory anxiety - "fear of fear"
agoraphobia
Cause appears biological
Genetic
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MZ>DZ concordance rate
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30% of relatives with panic disorder have it
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family inheritance suggests single, dominant gene
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relationship with bipolar disorder?
lactic acid
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triggers panic attacks in people with panic disorder, but not normals
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for those few normals who did get panic attacks, 24% of them turned
out to have relatives who had a history of anxiety disorders
habituation
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people with panic disorder take longer to habituate to annoying tones
temporal poles
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appear involved, probably associated with amygdala
prenatal benzodiazepine exposure
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produces fearfulness in cats
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with later administration of benzodiazepine reducing anxiety
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found to have fewer benzodiazepine receptors
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REMEMBER plant root story? What kind of sensitivity is this?
cholecystokinin (CCK)
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triggers panic attacks in panic disordered patients, but not normals
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however, CCK antagonist is not effective treatment
serotonin
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SSRIs useful in panic disorder
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However, tryptophan depletion has no effect
OBSESSIVE COMPULSIVE DISORDER
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1-2% of the population
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females slightly more likely than males to have the disorder
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most commonly begins in young adulthood
What are the 4 categories of compulsions?
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compulsions may be related to overactivity of "species-typical behaviors"
or cultural rituals
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related to Tourette’s syndrome
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damage to basal ganglia, cingulate gyrus, and prefrontal cortex may
cause OCD
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OCD sometimes found in Huntington’s and Sydenham’s chorea, both basal
ganglia disorders
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PET scans documented reduced orbitofrontal cortical activity 1 year
after tx
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drug therapy most effective treatment - serotonin agonists
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behavioral treatment involves response suppression
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frontal lobe surgery
serotonin
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treatment with serotonin reuptake blockers - clomipramine
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serotonin antagonists worsen symptoms
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tryptophan depletion has no effect
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has inhibitory effect on species-specific behaviors
AUTISM
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4 in every 10,000 births
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often first born and last (in a series) born children
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MZ concordance as high as 96%
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DZ the same as for siblings
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2-3% of siblings also are autistic, which is 50-100 times greater than
general population incidence
possible role of perinatal complications
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for those few MZ twins who were discordant, the affected twin was likely
to have suffered obstetric complications
phenylketonuria (PKU)
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results in severe mental retardation and, in some cases, autism if untreated
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causes failure of myelinization of neurons in the CNS
Tourette’s syndrome
fragile X syndrome
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leading hereditary cause of mental retardation
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unclear if associated with autism
associated with medical disorders:
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maternal exposure to rubella, infantile hydrocephalus
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12 rare diseases
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Joubert syndrome (deficient cerebellar development)
Stress Disorders
Glucocorticoids
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Hormones secreted during stress
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Help break down protein and convert to glucose
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Release controlled by neurons in the paraventricular nucleus of the
hypothalamus
Long-term stress
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Survivors of concentration camps
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Drivers of subway trains that have killed people
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Air traffic controllers
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Alzheimer's caregivers - wounds took longer to heal
Prolonged secretion of glucocorticoids
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Increased blood pressure
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Damage to muscle tissue
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Steroid diabetes
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Infertility
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Inhibition of growth
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Inhibition of inflammatory responses
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Suppression of the immune system
Also destroys neurons in CA1 of the hippocampus
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Glucocorticoids lower neurons ability to use glucose
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Particularly bad when blood flow is reduced (associated with aging)
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Higher blood levels, poorer maze learning in older people
Also can cause brain damage
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Monkey studies
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Brain degeneration in torture victims
Posttraumatic Stress Disorder
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Role of pre-existing personality factors
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Gene responsible for D2 receptor production
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Combat exposure related to hippocampal loss
Immune system
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White blood cells produce specific and nonspecific responses to invading
organisms
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What are nonspecific responses?
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What are specific responses?