Epidemiology/Biostatistics

1.        The five leading causes of death are heart disease, cancer, cerebrovascular disease, COPD and accidents/adverse effects. These are the same in whites and blacks.  Blacks have a greater death rate than the general population and also have increased mortality risk with most diseases. 

2.        Leading causes of cancer:
       Men:  Lung, prostate, colon/rectal, pancreas, non-Hodgkin’s lymphoma
       Women:  Lung, breast, colon/rectal, pancreas, ovary

3.        Prevalence of common psychiatric disorders: 

Alcoholism:  70% of the population drinks, 12% heavily.  Men:women = 2:1.  Low incidence among Jews and Orientals.  High among urban blacks and indians.  10% lifetime prevalence.
Drug abuse:  5% lifetime prevalence.  M>F.  By definition, it must impair social/occupational functioning to be drug abuse.

Bullemia/Anorexia nervosa:  >90% are female.

Schizophrenia:  1% lifetime prevalence.  Increased in urban and low S/E groups.

Major depression:  17% lifetime prevalence.  10X more frequent than bipolar disorder.

Depression(dysthymia): W:M 2-3:1; 6% lifetime prevalence.

4.        Morbidity = sick rate
     Mortality = death rate

5.        HIV transmission 
  45-60%         homosexual/bisexual men
  20-25%         IV drug users
  13%              heterosexuals
  <1%              perinatal

6.        Types of studies:
        Randomized clinical trial:  Investigator assigns individuals to study and control groups by a random process (syn: controlled clinical trial)
        Cohort:  Study begins by identifying individuals with and without a factor being investigated.  These factors are identified with and without knowledge of which individuals have or will develop disease (e.g. – identify people on NSAIDS and not on NSAIDS and see which develop PUD later)

Case control: Identify those with disease(case) and without disease(control) without knowledge

of exposure of subjects to factors being investigated (e.g. – identify post menopausal subjects with and without breast cancer and see how many are nulliparous).

7.  Standard deviation : measures the spread of data (how far in general it is from the mean). 

p-value: probability of obtaining data at least as extreme as that obtained in the investigation’s sample      set if the null hypothesis were true.  (The smaller the p-value, the larger your confidence interval)
mean: sum of measurements/number of measurements
median: half of the data values occur above, half below the median.
Mode: most frequently occurring data value.

8.  You can change a test’s criteria to make it more sensitive(fewer false negatives) or specific(fewer false positives)

(Add epi, neruophysiology, psych 1-2)

Psychiatry

3.       Diseases associated with personality types.

·         There is only one specific conditioned shown to be convincingly associated with a particular personality trait – coronary artery disease appears more common in people who are more hostile.

·         It is hypothesized that it is connected to the adrenalin surge that accompanies angry outbursts.

4.       Clinical features and treatment of phobias.

·         Phobia disorders are the most common psychiatric disorder.

·         More than 12% have a phobic disorder in some circumstances.

·         Only 1% is significantly disabling.

·         Many begin in young women (15-30) from stable families.

·         Relief occurs with escape, thus reinforcing the avoidance pattern – a vicious cycle.

·         One of the best studied and most debilitating is agrophobia.  This is a combination of multiple anxieties:  fears of open/closed spaces, crowded places, unfamiliar places, being alone.  In general it is a loss of sense of security.  Depression is common and most patients also have panic attacks (panic disorder with agrophobia).

·         Other phobia:  public speaking, public bathrooms (males), animals, storms, needles, etc.

·         Most phobias, social or specific are more frequent among women.

·         Treatment:

-b-blockers can be used before public speaking.

-Mild tranquilizers can be used temporarily to confront the phobia.

-SSRIs and MAOIs are effective for generalized social phobias.

-Agrophobia, with or without panic attacks, can be treated with anti-anxiety medications (TCAs, MAOIs, alprazolam).

-Cognitive-behavior therapy is essential.  Exposure is the key treatment:  systematic desensitization-graded exposure; flooding – face feared object directly; or implosion – thinking about it.

5.       Clinical features of child abuse.

·         There are 4 classic types of child abuse: emotional, neglect, physical, and sexual abuse.

·         Emotional abuse is the most common and often overlooked.

·         Neglect is the most under-reported and can include physical, emotional, and educational neglect.

·         One third of abusers have been abused themselves.

·         Children who are particularly at risk are the  ADHD, conduct disorders, difficult temperaments, low birth weight, and sick children.

·         Younger children are more likely to be physically abused.

·         Mothers are more likely to abuse prepubertal children, while fathers adolescents.

·         Some of the typical symptoms:

Sleep disorders, developmental delays, antisocial behavior, poor self-esteem, runaway, lying, stealing, fire starting, drug and alcohol abuse, borderline PD, dissociation (multiple personalities).  See First Aid for the physical symptoms.

6.       Clinical features of common learning disorders.

·         Rule out: hearing/vision loss, language difficulties, poor attendance.

·         When aptitude tests (measures potential to learn) are greater than achievement tests consider a learning disorder.

·         Dyslexia – difficulty reading

Seems to be reading the book, but later becomes clear the child is guessing at simple words and looking at pictures.

·         Dyscalcula – great difficulty in math.

Everything is rote memorization and not understanding.

·         Mental retardation (<18 years old, ¯ IQ – less than 2 standard deviations, ¯ functioning)

Mild                           IQ 50-70 85%        Usually recognized when enter school; most self sufficient

Moderate  IQ 35-50 10%        Learn simple skills; supported lifestyle

Severe                       IQ 20-35 4%          Simple speech; supported care

Profound   IQ <20                    1%          Significant neurological damage, complete care required

·         Down syndrome and fragile X syndrome are the number one and two causes, respectively, of mental retardation.  Social causes produce most of the mild retardation (e.g. environmental deprivation, abuse, neglect).  Fetal alcohol syndrome is the number one cause of mental retardation.

7.       Therapeutic applications of learning theories.

·         Classical Conditioning – behavior are built from stimulus-response connections.  Behavior is built up out of, and linked to, simple reflexes by association.  Usually they are associated because they occur close together in time.

·         Classical Conditioning has four components:  Unconditional Stimulus - food (UCS), Unconditional Response – salivation (UCR), Conditioned Stimulus - bell (CS), and Conditioned Response – salivation (CR).

·         Reinforcement – pairing of CS & UCS ® develops the effectiveness of the CS to elicit the CR.  Irregular pairing most effective.

·         Extinction – deleting the UCS will eventually lead to stopping of CR.

·         Pavlovian A conditioning – UCS is positive (pleasurable); Pavlovian B conditioning – UCS is unpleasant

·         An example:  A child comes to the physician’s office for a shot (UCS).  She cries when she gets the shot from the nurse (UCR).  The next month she sees the same nurse (CS) and starts to cry (CR).  In time if the sight of the nurse is not followed by a shot the conditioned response (crying) will stop – extinction.

·         Other examples – Alcoholism and Antabuse, Food aversion in children with cancer, treatment of phobias.

·         Operant Conditioning – feature behavior is contingent upon the consequences (reinforcement) of that original behavior.  A person’s behavior, ideas, and personality are the products of the “histories of reinforcement” experienced by that person throughout life.

·         Behavior that is not part of the individual’s natural repertoire can be learned through reward or punishment.

·         Positive reinforcement is a positive stimulus that increases the rate of behavior.

·         Negative reinforcement (escape) is the removal of an aversive stimulus that increases the rate of behavior.  An example would be a child who increases his study behavior to avoid losing television privileges.

·         Punishment is an aversive stimulus aimed at reducing an unwanted behavior.

·         The pattern or schedule of reinforcement affects how quickly a behavior is learned or disapears.

-Fixed ratio schedule

-Fixed interval schedule

-Variable-ratio schedule (best one)

-Variable interval schedule

8.       Problems associated with the physician-patient relationship.

·         Factors that increase patient compliance

-Good physician-patient relationship

-Feeling ill

-Older physician

-Short period spent in the waiting room

-Written instructions for taking medication

-Acute illness

-Simple treatment schedule

-One behavioral change at a time

9.       Management of the suicidal patient.

·         Ask – should patient be hospitalized.  Be conservative.

·         Identify and treat psychiatric or medical conditions.

-Treat depression vigorously.

-If determinedly suicidal, use ECT (electroconvulsive therapy) instead of waiting for medication response.

·         Develop an alliance with the patient.

-Allow to express anger, feelings of hopelessness.

-Try to understand why the patient wants to die.

·         Suicidal patients are often ambivalent about death.

-Point this out to them, show them the evidence of their desire to live.

-Make plans with/for patient.

·         Try to reduce social isolation.

-Involve family/significant others.

-Involve community resources.

·         Suicidal potential can change rapidly – reassess frequently.

·         Many depressive suicides occur within 36 hours of discharge – don’t lose contact with patient.

·         Don’t minimize the seriousness of a suicide attempt.

·         Don’t explain away the patient’s symptoms.

·         Don’t agree to hold a suicide plan in confidence.

·         Many patients with severe depression do not have the energy to commit suicide.  The risk of suicide increases as depression begins to diminish and energy to act on suicidal impulses returns with treatment.

10.    Addiction:  risk factors, family history, behavior, factors contributing to relapse.

·         Genetic evidence for alcoholism: 4 times the normal risk if one parent, 60% risk if both parents are alcoholics.

·         Type 1 alcoholics – adult onset; gradually escalating consumption, male and females; modest family history; 75% of alcoholics.

·         Type 2 alcoholics – adolescence and early adulthood; risk taking and anti-social characteristics; primarily male; very resistant to treatment; strong family history; 25% of alcoholics.

·         Other predictive, inherited biological features are associated with alcoholism (particularly in males):

-Resistant to intoxication – very high risk of developing alcoholism.

-Subnormal rise of cortisol after drinking.

-Subnormal release of epinephrine following stress.

·         Alcohol stimulates the release of dopamine producing euphoria.  Over time natural levels of dopamine fall unless stimulated by alcohol – very reinforcing.  Natural dopamine levels may take months or years to recover.

·         The majority of alcoholics die 15 years early – usually form heart disease or cancer.

·         6% life-time prevalence of drug abuse in the U.S. and males > females in all age groups.

·         Abusers are not all alike but do have some common features:

-Marked depression and anxiety.

-Increased dependency needs.

-Low self-esteem.

-Familial associations with antisocial personality.

-Dysfunctional family

-A chronic course resistant to treatment.

-Drug use to treat psychiatric illnesses are modestly abused but more commonly chronic abuse produces emotional problems.