BIOLOGICAL THEORIES

REVOLUTION – 1970’s - PRESENT FROM PSYCHOLOGICAL PERSONALITY EARLY LIFE PSYCHOTHERAPY 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 OR CURES FOR M.I. RISE AND DOMINANCE OF PSYCHODYNAMIC THEORY DISCREDITING OF GENETIC THOUGHT WITH NAZIS

EMERGENCE OF BIOLOGY SCIENTIFIC REVOLUTION NEW TECHNOLOGY FOR THE STUDY OF THE BRAIN (CAT; MRI; PET) MUCH MORE KNOWLEDGE ABOUT BRAIN PSYCHOPHARMACOLOGICAL DEVELOPMENTS

EMERGENCE OF BIOLOGY INSURANCE AND MANAGED CARE DRUGS CHEAPER AND MORE EFFICIENT CAN TREAT SERIOUSLY ILL

CONCEPT

DSM-III (1980) REJECTED DYNAMIC MODEL OF DSM-I AND DSM-II ADOPTED DIAGNOSTIC MODEL SYMPTOMS INDICATE UNDERLYING DISEASES NOT CONTINUOUS, BUT CATEGORICAL

CAUSES

CAUSES BRAIN DISORDERS OFTEN GENETIC VULNERABILITIES EARLY CHILDHOOD ILLNESSES OR TRAUMAS CURRENT TRAUMAS CAN CHANGE BRAIN

EVIDENCE FOR GENETIC 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

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

TWIN STUDIES

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. 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

neurochemistry

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