Transcript biological theories

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.?
• RESULTS OF USING MEDICATION?
• NO EVIDENCE YET THAT
GENETIC/BIOLOGICAL CAUSES ARE
MORE IMPORTANT THAN OTHERS
TREATMENT
• BEFORE LOBOTOMY, ECT (SHOCK),
COMA - NOW DRUGS
• CHANGE NEUROCHEMISTRY OF
BRAIN
• CHANGE WHAT RECEPTORS ABSORB
SO ELEVATE OR LOWER LEVELS OF
NEUROTRANSMITTERS IN SYNAPSES
TREATMENTS
• ANTI-PSYCHOTICS
• PHENOTHIAZINES AND CLOZAPINE
FOR SCHIZOPHRENIA
• LITHIUM FOR BIPOLAR
• MOST ARE ILLNESS SPECIFIC
SSRI’S
• SELECTIVE SEROTONIN REUPTAKE
INHIBITORS - PROZAC, PAXIL,
XOLOFT (LATE 1980’S)
• UNLIKE OLDER DRUGS ARE
SPECIFICALLY DESIGNED TO
PREVENT REUPTAKE OF SEROTONIN
• NOT ILLNESS SPECIFIC (NOT “ANTIDEPRESSANTS”)
Psychotropic Prescribing in USA
(IMS - S Units)
10000000
9000000
8000000
7000000
6000000
5000000
4000000
3000000
2000000
1000000
0
Antidepressant
Antipsychotic
1990 1992 1994 1996 1998 2000 2001
HUGE GROWTH
• 10% OF ADULT POPULATION NOW
TAKING AN SSRI
• 3 OF 7 BEST SELLING PRESCRIPTION
DRUGS OF ANY KIND ARE SSRI’s
• 300% INCREASE IN PAST 10 YEARS IN
NUMBER OF CHILDREN AND
ADOLESCENTS TAKING MEDICATION
ARE SSRI’S BETTER?
• NOT MORE EFFECTIVE THAN OLDER
DRUGS
• FEWER NEGATIVE SIDE EFFECTS
(ALTHOUGH POSSIBLY MORE
SUICIDE RISK)
• NOT ADDICTING
• LESS RISK OF OVERDOSE
DOWNSIDE OF SSRI’S
• NOT MUCH BETTER THAN PLACEBOS
FOR LESS SEVERE CONDITIONS
• LONG-TERM EFFECTS?
• ONLY ELIMINATE SYMPTOMS, NOT
UNDERLYING PROBLEM?
• BETTER ALTERNATIVES?
• NOT GOOD FOR UNDER AGE 18?
STRENGTHS OF BIOLOGY
• BEST FOR PSYCHOTIC DISORDERS
• MORE KNOWLEDGE ABOUT BRAIN
• ADVANCES IN DRUG TREATMENTS
FOR MANY CONDITIONS