Chapter Fifteen Alcoholism, Mood Disorders, and Schizophrenia

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Chapter FifteenAlcoholism, Mood Disorders, and
Schizophrenia
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Alcoholism

• Defined-cannot stop drinking or control the
  amount you consume
• Genetics
• Two Types of Alcoholism
• Type 1 Type II
• Less genetic Stronger genetic basis
• Develops gradually Rapid, early onset
• Affects men and women equally Overwhelmingly
  men
• Concordance rates in twins is .55

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Figure 15.3  Design for studies of predisposition
to alcoholismSons of alcoholic fathers are
compared to other young men of the same age and
same current drinking habits. Any behavior that
is more common in the first group is presumably a
predictor of later alcoholism.
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Alcohol Metabolism and Antabuse

• Antabuse
• Drug used to treat alcoholism
• Mechanism-stops metabolism of alcohol
• Results in nausea, headache and stomach pain when
  alcohol is consumed
• Only moderately effective

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Risk Factors for Alcohol Abuse

• Sons of alcoholics report low intoxication after
  drinking
• Sons of alcoholics are more likely to report
  stress relief from drinking

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Depression

• Major Depressive Disorder
• Defined-long-term sadness and helplessness
• Etiology
• Observed more often in women than men
• Peak frequency between 25 and 44
• About 19 of all people suffer a bout of
  depression at least once in their lives
• Genetics
• Depression does have a genetic link
• Gene has not been located

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Depression

• Triggering Depressive Episodes
• depression is episodic
• Can be triggered by an event (ex death of a
  loved one, birth of a child, etc)
• Potential Physiological Mechanisms
• Abnormalities of Hemispheric Dominance
• Depressed people have more activity in the right
  prefrontal cortex than the left prefrontal cortex
• Depression more commonly follows left-hemisphere
  damage
• Viruses
• Borna virus is found more commonly in depressed
  populations than in non-depressed populations

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Depression

• Treatments
• Antidepressants
• Tricyclics-prevent reuptake of serotonin or
  norepinephrine/epinephrine
• MAO Inhibitors-block MAO from breaking down
  serotonin and norepinephrine/epinephrine
• SSRIs-block reuptake of serotonin
• Atypical antidepressants-miscellaneous group
• ECT
• Applied every other day for two weeks
• Muscle relaxants and anesthetics minimize
  discomfort
• Memory loss can be a side-effect (limited if
  shock is given to right hemisphere only
• Altered Sleep Patterns
• Treat patient like someone with difficulty
  adjusting to changing time zones

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Figure 15.7  Routes of action of
antidepressantsTricyclics block the reuptake of
dopamine, norepinephrine, or serotonin. SSRIs
specifically block the reuptake of serotonin.
MAOIs block the enzyme MAO, which converts
dopamine, norepinephrine, or serotonin into
inactive chemicals. Atypical antidepressants have
varying effects.
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Depression

• Physiology of Depression
• Two Conclusions
• Mood depends on the effects of a combination of
  transmitters
• Different depressed people have somewhat
  different transmitter abnormalities

Video
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Bipolar Disorder

• Defined-alternate between mania and depression
• Etiology
• May last only days or for a year or more
• 1 of people have a mild case at some time in
  life
• Average age of onset is early 20s
• Genetics
• Concordance rate is .50
• No specific gene has been identified

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Bipolar Disorder

• Treatments
• Lithium
• Stabilizes mood
• Mechanism unknown but likely involves second
  messenger systems
• Anticonvulsant drugs
• Mechanism of action is on second messenger systems

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Seasonal Affective Disorder

• Defined-depression that regularly recurs in a
  particular season
• Usually treated by bright light therapy

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Schizophrenia

• Characteristics
• Deteriorating ability to function
• Accompanied by delusions, hallucinations, thought
  disorder, movement disorder and inappropriate
  emotional expression
• Behavioral Symptoms
• Positive Symptoms-behavior that are present that
  should be absent
• Delusions, hallucinations, thought disorders
• Negative Symptoms-behavior that is absent that
  should be present
• Weak social interactions, emotional expression,
  speech, and working memory

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Schizophrenia

• Characteristics Contd
• Acute-sudden onset with good prospects for
  recovery
• Chronic-gradual onset and a long-term course of
  treatment and resistance

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Schizophrenia

• Etiology
• About 1.3 of people will suffer from
  schizophrenia at some point in their lives
• More common in developed countries
• Equal occurrence for men and women
• Onset is usually in the 20s

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Schizophrenia

• Genetics
• Concordance rate is 50
• However, genes are not the only influence
• A gene has not been located for schizophrenia

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Figure 15.15  Probabilities of developing
schizophreniaThe closer the genetic relationship
to someone with schizophrenia, the higher the
probability of developing it oneself.
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Hypotheses of Causation in Schizophrenia

• Neurodevelopmental
• Either genes or difficulties early in life impair
  brain development in ways that lead to
  schizophrenic-like symptoms in early adulthood
• Dopamine Hypothesis-Excess dopamine activity
  causes behavioral changes associated with
  schizophrenia
• Supported by drug treatments that target dopamine
• Glutamate Hypothesis-the problem is deficient
  glutamate activity
• Phencyclidine-Inhibits glutamate type NMDA
  receptors and produces both positive and negative
  symptoms of schizophrenia

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Schizophrenia Treatment
Antipsychotic Drugs-All block postsynaptic
dopamine receptors Phenothiazines-chlorpromazine B
utyrophenones-haloperidol Atypical
Antipsychotics-clozapine (blocks D4 receptors but
not D2)