PSYCH 415--Key terms for psychological disorders

SCHIZOPHRENIA

• positive symptoms - thought disorder, hallucinations, delusions
• negative symptoms - flattened (blunted) affect, poverty of thought, social withdrawal, deterioration in behavior (these occur in many neurological disorders)
• incidence - 1% (most common onset in adolescents and young adults age 20-30)
• heritability
  • twin studies - monozygotic (MZ) twins compared to dizygotic (DZ) twins
  • Gottesman & Bertelsen (1989)
  • Kety et al (1968)
• congenital factors - factors present at birth but not inherited
• dopamine hypothesis (theory)
  • neuroleptic drugs
  • amphetamine-induced stereotypy
  • Parkinsonian side effects
  • dopamine pathways - nigrostriatal vs. mesolimbic and mesocortical systems
  • amphetamine psychosis
  • autopsy and PET scanning studies
• problems with the DA theory
  • not all patients respond to neuroleptic therapy
  • response to drug therapy is delayed
  • tardive dyskinesia - denervation supersensitivity
• schizophrenia as a neurological disorder
  • neurological symptoms
  • general brain atrophy
  • hippocampus
  • hypofrontality - Wisconsin Card Sort Test (dorsolateral prefrontal cortex function)
• the virus theory of schizophrenia
  • AIDS-related dementia
  • rabies
  • herpes simplex encephalitis
  • influenza
  • slow infections or prion disease
• lately, a lot of interest has centered on two areas of the brain
  • the hippocampus
  • the dorsolaterial prefrontal cortex - possible role in STM

AFFECTIVE DISORDERS

• reactive vs. endogenous depression
• unipolar vs. bipolar depression
• incidence (DSM): 20% of women and 10% of men (probably gross overestimates; book says 6%)
• heritability: 69% of MZ twins were concordant, 13% of DZ twins were concordant
• effective therapies
  • traditional psychotherapy hasn't been very effective with endogenous depression
  • biomedical treatments
    • MAO inhibitors: iproniazid (the classic one)
    • tricyclic antidepressants: imipramine (Tofranil), amitriptyline (Elavil)
    • new generation antidepressants or SSRIs: fluoxetine (Prozac)
    • selective norepinephrine-reuptake inhibitors: reboxetine
    • lithium salts (lithium carbonate): for bipolar disorder
    • electroconvulsive therapy (ECT)
    • sleep deprivation
• the monoamine (or biogenic amine) hypothesis (theory)
  • treatments that deplete the brain of MA cause depression: e.g., reserpine
  • suicidal depression is associated with low 5-HIAA levels in CSF
  • drugs successful at alleviating depressive symptoms are MA agonists
  • diets that deplete 5-HT (low tryptophan diets) cause relapse
  • evidence for upregulation of NE and 5-HT receptors during successful treatment
• questions
  • is the DA reward system involved?
  • why does it take antidepressant drugs 2-3 weeks to have a therapeutic effect?
• according to one promising theory, the key characteristic of effective treatments for endogenous depression seems to be their ability to alter beta-NE receptor sensitivity
  • all effective treatments reduce sensitivity of postsynaptic beta-NE receptors
  • the therapeutic response has the same time course as the change in receptor sensitivity
  • reserpine makes beta-NE receptors supersensitive
  • change in receptor sensitivity somehow involves the action of 5-HT neurons
• relationship of depression to circadian rhythms
  • one of the most prominent symptoms of depression is disorganized sleep
  • one of the most effective treatments for depression is REM sleep deprivation
  • the Wu & Bunney theory - a depressogenic substance is produced during sleep
• seasonal affective disorder (SAD)
• PET scanning studies
  • drug-free depressives, both those actively depressed and those in remission, show increased activity in the amygdala
  • those in an episode of active depression show increased activity in the prefrontal cx.

ANXIETY DISORDERS

• obsessive-compulsive disorder (OCD)
  • obsessions - persistent, irresistible thoughts
  • compulsions - persistent, irresistible behaviors
  • incidence - about 2%, slightly more in women than men and in young adults
  • most effective treatment - drug therapy (often used in combo with behavior therapy)
  • all therapeutic drugs block 5-HT reuptake: clomipramine, fluoxetine (Prozac), fluvoxamine
  • antidepressants also work - but antiobsessional effects unrelated to antidepressive effects
  • PET scanning studies - increase glucose utilization in: caudate nuc., cingulate gyrus, orbitofrontal cx
  • after successful drug or behavioral therapy, glucose utilization in caudate and orbitofrontal cx tends to return to normal levels
• panic disorder - panic (anxiety) attacks
  • incidence - 1-2%, 2X more common in women, onset in young adulthood
  • a single dominant gene is suspected to confer a hereditary predisposition
  • treatment - combo of benzodiazepines and behavior therapy
  • PET scanning studies
    • panic attacks can be induced by injection of lactic acid or inhalation of CO₂
    • the anterior temporal lobes "light up" - amygdala, uncus, etc. increased glucose utilization occurs in the temporal poles of normal Ss who are experiencing anxiety, too
• general anxiety (generalized anxiety disorder)
  • the role of GABA
    • anxiolytic drugs are (almost) all GABA agonists: benzodiazepines, barbiturates, alcohol
    • GABA-A receptor complex - gates a chloride channel
    • anxiety disorders may result in chronic decrease in sensitivity - due to decreased number of benzodiazepine receptors?
    • effect of prenatal diazepam (Valium) in kittens
  • buspirone (Buspar) - 5-HT agonist
    • anxiolytic but not sedating or ataxigenic
    • acts at the 5-HT1A receptor
  • role of the amygdala - local infusions of GABA antagonists prevent the anxiolytic effects of systemically administered benzodiazepines in animal experiments

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