Download USMLE Step 1 Web Prep — Alcohol and Alcoholism 155960 >>> 00

USMLE Step 1 Web Prep — Alcohol and Alcoholism
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SLIDE 1 of 10
Substance Abuse
Alcohol and Alcoholism
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SLIDE 2 of 10
Physiology of Substance Abuse
 The basic addiction pathway in the brain is a dopamine pathway
 Activation of this pathway accounts for the “positive reinforcement” feeling
Medial forebrain bundle (MFB)
Nucleus accumbens (NAC)
Ventral tegmental area (VTA)
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SLIDE 3 of 10
Physiology of Substance Abuse
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Pathway helps to make behavior adaptive and goal directed.
Ingestion of chemicals gives the positive reinforcement without the linkage to
environment
Makes behavior less and less environmentally responsive over time.
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SLIDE 4 of 10
Physiology of Substance Abuse
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This addiction pathway is activated by all substances that produce
psychological dependence
Serotonin (5-HT) also plays a role in the addiction process due to its regulation
of impulse control
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SLIDE 5 of 10
Alcohol and Alcoholism
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Cost the US around $100 billion a year
Most costly health problem
Tobacco accounts for more loss of life
The best way to reduce long-term mortality is to eliminate smoking
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SLIDE 6 of 10
Epidemiological Facts
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Alcohol: most abused drug for all ages
10% of all adults are problem drinkers
Male to female ratio is 4 to 3
Since 1980, per capita consumption of alcohol has declined
o The proportion of heavy drinkers younger than 20 has increased
o Binge drinking is becoming more common
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SLIDE 7 of 10
Alcohol and SES
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Alcoholism rates are higher for the low SES groups
Low SES alcoholics recover sooner and at higher rates (if they survive)
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SLIDE 8 of 10
Accidents
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Alcohol use has been implicated in 15% of all auto accidents
Alcohol use implicated in 50% of all:
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Auto accidents not involving a pedestrian
Auto accident deaths
Homicides (killer or victim)
Hospital admissions
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SLIDE 9 of 10
Fetal Alcohol Syndrome
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The leading known cause of mental retardation (Down’s syndrome is second)
o Characterized by:
 developmental and mental retardation
 craniofacial abnormalities
 limb dislocation
o Consumption of large quantities of alcohol needed to produce FAS
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SLIDE 10 of 10
Evidence for Genetic Contribution
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Increasing evidence for genetic contribution
Concordance rates: MZ > DZ
Marked ethnic-group differences
Capacity to tolerate alcohol is the key (enzyme induction, lack of tyrosine
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kinase)
If biologic father was an alcoholic, the incidence of alcoholism in males
adopted into nonalcoholic families is equal