Transcript February 15, Biological Theories

REVOLUTION – 1970’s PRESENT
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FROM
PSYCHOLOGICAL
PERSONALITY
EARLY LIFE
PSYCHOTHERAPY
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TO
BIOLOGICAL
DISEASE
BRAIN
MEDICATION
HISTORY
• DOMINANT IN 19TH CENTURY DISEASE OF BRAIN
• MOST OF 20TH CENTURY - LIMITED
TO MENTAL HOSPITALS (1900 - 1970)
UP UNTIL ABOUT 1970
• LITTLE KNOWLEDGE ABOUT BRAIN
• RISE AND DOMINANCE OF
PSYCHODYNAMIC THEORY
• DISCREDITING OF GENETIC
THOUGHT WITH NAZIS
EMERGENCE OF BIOLOGY
• SCIENTIFIC REVOLUTION BEGAN IN
1970s
• NEW TECHNOLOGY FOR THE STUDY
OF THE BRAIN (CAT; MRI; PET)
• MUCH MORE KNOWLEDGE ABOUT
BRAIN – HUMAN GENOME PROJECT
• PSYCHOPHARMACOLOGICAL
DEVELOPMENTS
EMERGENCE OF BIOLOGY
• INSURANCE AND MANAGED CARE
• DRUGS CHEAPER AND MORE
EFFICIENT
• CAN TREAT SERIOUSLY ILL
DSM-III (1980)
• REJECTED DYNAMIC MODEL OF
DSM-I AND DSM-II
• ADOPTED DIAGNOSTIC MODEL
• SYMPTOMS INDICATE UNDERLYING
DISEASES
• NOT CONTINUOUS, BUT
CATEGORICAL
CAUSES
• BRAIN DISORDERS
• OFTEN GENETIC VULNERABILITIES
• EARLY CHILDHOOD ILLNESSES OR
TRAUMAS
• CURRENT TRAUMAS CAN CHANGE
BRAIN
EVIDENCE FOR GENETIC
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PROBABILITY OF SCHIZOPHRENIA
NO SCHIZ RELATIVES
1%
UNCLES/AUNTS/COUSINS 2-4%
ONE PARENT
6%
FULL SIBLING
10%
DZ
6-15%
MZ
30-40%
BASIC PROBLEM
• FAMILIES TRANSMIT GENES AND
BEHAVIORS, VALUES, CULTURE, ETC.
• HOW SEPARATE GENETIC FROM
ENVIRONMENTAL INFLUENCES?
• TWO MAJOR WAYS
• ADOPTION STUDIES, TWIN STUDIES
ADOPTION STUDIES
• GET GENES FROM ONE SET OF
PARENTS AND ENVIRONMENT FROM
ANOTHER SET
• NATURAL CHILDREN OF M.I.
PARENTS RAISED BY NON-M.I.
FOSTER PARENTS
• COMPARE TO ADOPTED CONTROL
GROUP
DESIGN
A
BORN
MI
RAISED
NATURAL
B
BORN
MI
RAISED
FOSTER
C
BORN
~ MI
RAISED
FOSTER
D
RATE OF
MI IN
GENERAL
POP.
HESTON STUDY
• 47 CHILDREN BORN TO SCHIZ.
MOTHER IN OREGON M.H. 1915-45
AND TAKEN AWAY AT BIRTH
• CONTROL GROUP OF 47 CHILDREN
OF NON-M.I. MOTHERS ADOPTED AT
BIRTH
HESTON (CONT.)
• 17% OF CHILDREN BORN OF SCHIZ.
MOTHERS BECAME SCHIZ.
• 0% OF CONTROL GROUP
• OTHER STUDIES OF SCHIZOPHRENIA
ALSO SUPPORT GENETIC INFLUENCE
(ALTHOUGH NOT AS STRONGLY)
ALCOHOL AND ADOPTION
• GOODWIN – DENMARK
• CHILDREN OF ALCOHOLICS RAISED BY
NATURAL OR FOSTER PARENTS
• FOR MALES, FIND RATES OF ALCOHOLISM
AS ADULTS COMPARABLY HIGH FOR
CHILDREN OF ALCOHOLICS RAISED BY
NATURAL OR FOSTER PARENTS
• INDICATES GENETIC INFLUENCES
GOODWIN (CONT.)
• FOR FEMALES, DAUGHTERS OF
ALCOHOLIC PARENTS DO NOT HAVE
MORE ALCOHOLISM WHEN RAISED
BY NATURAL OR FOSTER PARENTS
THAN OTHERS
• DOES NOT INDICATE GENETIC
CAUSES
OTHER ILLNESSES
• DEPRESSION
• RATES IN ADOPTEES OFTEN
RESEMBLE FOSTER PARENTS MORE
THAN NATURAL PARENTS
• INDICATES MORE ENVIRONMENTAL
THAN GENETIC INFLUENCES
COMPARE MZ - DZ TWINS
• MONOZYGOTIC TWINS (MZ) - SHARE
100% GENES
• DYZYGOTIC TWINS (DZ) - SHARE 50%
GENES
• RAISED IN SAME FAMILY, ETC.
• CONTROL ENVIRONMENT, VARY
GENES
DIFFERENCES IN SCHIZ.
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SIBLINGS 10%
DZ
6-15%
MZ
30-40%
OTHER DISORDERS LESS
DIFFERENCE BUT ALWAYS MORE MZ
THAN DZ
LIMITS OF TWIN STUDIES
• MZ CONCORDANCE FAR FROM 100%
• ARE TWINS REPRESENTATIVE?
• EXTENT GREATER CONCORDANCE
FOR MZ IS SOCIAL NOT GENETIC
• PHYSICAL SIMILARITY, MORE
INTERACTION, SAME FRIENDS
NEURONS
NEUROCHEMISTRY
• NEURONS (BRAIN CELLS) RELEASE
• NEUROTRANSMITTERS (CHEMICALS
THAT COMMUNICATE BETWEEN
NEURONS) INTO
• SYNAPSES - GAP BETWEEN NEURONS
• RECEPTORS - ABSORB CHEMICALS
NEUROCHEMISTRY (CONT.)
• MENTAL ILLNESSES CAN ARISE
FROM
• MALFUNCTIONING RECEPTORS
• TOO MUCH OR TOO LITTLE OF
VARIOUS NEUROTRANSMITTERS
MAJOR NEUROCHEMICALS
• SEROTONIN - LOW LEVELS MAY BE
RELATED TO DEPRESSION AND
MANY OTHER MENTAL ILLNESSES
• DOPAMINE - HIGH LEVELS MAY BE
RELATED TO SCHIZOPHRENIA
• NOREPINEPHRINE - HIGH LEVELS
MAY BE RELATED TO ANXIETY