Transcript February 14, 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
UP UNTIL ABOUT 1970
• RISE AND DOMINANCE OF
PSYCHODYNAMIC THEORY
• LITTLE KNOWLEDGE ABOUT BRAIN
• DISCREDITING OF GENETIC
THOUGHT WITH NAZIS
EMERGENCE OF BIOLOGY
• SCIENTIFIC REVOLUTION BEGAN IN
1970s
• MORE KNOWLEDGE ABOUT BRAIN –
HUMAN GENOME PROJECT NOW
• NEW TECHNOLOGY FOR THE STUDY
OF THE BRAIN (CAT; MRI; PET)
EMERGENCE OF BIOLOGY
• PSYCHOPHARMACOLOGICAL
DEVELOPMENTS
• INSURANCE AND MANAGED CARE
• DRUGS CHEAPER AND MORE
EFFICIENT THAN THERAPY
• CAN TREAT SERIOUSLY ILL
DSM-III (1980)
• REJECTED DYNAMIC MODEL OF
DSM-I AND DSM-II
• ADOPTED DIAGNOSTIC MODEL
DIAGNOSTIC MODEL
• NOT CONTINUOUS, BUT
CATEGORICAL
• SYMPTOMS INDICATE UNDERLYING
DISEASES
PROBLEM W/CONCEPT
• NO “GOLD STANDARD” FOR
UNDERLYING DISEASE
• CIRCULAR – USE SYMPTOMS TO
INDICATE DISEASE BUT ONLY KNOW
IF DISEASE THROUGH SYMPTOMS
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
• 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
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)
OTHER ILLNESSES
• DEPRESSION AND ALCOHOLISM
• RATES IN ADOPTEES SOMETIMES
RESEMBLE FOSTER PARENTS MORE
THAN NATURAL PARENTS
• INDICATES ENVIRONMENTAL AS
WELL AS 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
• CAN’T LOCATE PARTICULAR CAUSE
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
?s
• ARE NEUROCHEMICAL
ABNORMALITIES CAUSES OR
EFFECTS OF M.I.?
• NO EVIDENCE YET THAT
GENETIC/BIOLOGICAL CAUSES ARE
MORE IMPORTANT THAN OTHERS