Download Consciousness Chp. 6

Drugs and Consciousness
Drugs and Consciousness
 Psychoactive Drugs: A chemical substance
that alters perceptions and moods (affects
consciousness).
Dependence and Addiction
Continued use of a
psychoactive drug
produces tolerance.
With repeated exposure
to a drug, the drug’s
effect lessens. Thus it
takes greater quantities
to get the desired effect.
Withdrawal and Dependence
1.
Withdrawal: Upon stopping use of a drug
(after addiction), users may experience the
undesirable effects of withdrawal.
2.
Dependence: Absence of a drug may lead to a
feeling of physical pain, intense cravings
(physical dependence), and negative emotions
(psychological dependence).
Misconceptions about Addiction
Addiction is a craving for a chemical substance,
despite its adverse consequences (physical &
psychological).
1.
Addictive drugs quickly corrupt.
2.
Addiction cannot be overcome voluntarily.
3.
Addiction is no different than repetitive
pleasure-seeking behaviors.
Psychoactive Drugs
Psychoactive drugs are divided into three groups.
1. Depressants
2. Stimulants
3. Hallucinogens
Depressants
Depressants are drugs that reduce neural activity
and slow body functions. They include:
1. Alcohol
2. Barbiturates
3. Opiates
Alcohol
1. Alcohol affects motor skills, judgment, and
memory…and increases aggressiveness while
reducing self awareness.
Drinking and Driving
Stages of Alcohol Intoxication
 1. Subclinical (0.01-0.05)- Nearly normal behavior
 2. Euphoria (0.03-0.12)- Mild euphoria, sociability,
increased self-confidence; decreased inhibitions
diminution of attention, judgment and control
 3. Excitement (0.09-0.25)- Emotional instability; loss of
critical judgment, impairment of perception, memory and
comprehension, reduced visual acuity; peripheral vision
and glare recovery, sensory-motor incoordination;
impaired balance, drowsiness
Stages of Alcohol Intoxication
 4. Confusion (0.18-0.30)- Disorientation, mental confusion;
dizziness, exaggerated emotional states, disturbances of
vision and of perception of color, form, motion and
dimensions, increased pain threshold, increased muscular
in-coordination; staggering gait; slurred speech, apathy,
lethargy
 5. Stupor (0.25-0.40)- General inertia; approaching loss of
motor functions, markedly decreased response to stimuli,
marked muscular incoordination; inability to stand or walk
vomiting; incontinence, impaired consciousness; sleep
Stages of Alcohol Intoxication
 Coma (0.35-0.50)- Complete unconsciousness,
depressed or abolished reflexes, subnormal body
temperature, incontinence, impairment of circulation
and respiration, possible death
 Death (0.45 +)- Death from respiratory arrest
BAC Calculations
 BAC Depends on:
1.
# of Drinks
2.
Type of Drink
3.
Weight
4. Amount of Time Drinking
5.
http://www.ou.edu/oupd/bac.htm
Barbiturates
Barbiturates: Drugs that depress the activity of the
central nervous system, reducing anxiety but
impairing memory and judgment. Nembutal, Seconal,
and Amytal are some examples.
Effects of Barbiturates on the Brain
 Exact mechanisms not understood
 Thought to bind to sodium channels on neurons and
prevent the flow of sodium ions. Because sodium ions
cannot flow across the neuronal membrane, action
potentials cannot be produced.
 May also increase flow of chloride ions affecting GABA
Interesting Barbiturate Facts
 The barbiturate called sodium
pentothal is known as "truth
serum." However, it really does
NOT cause people to tell the truth.
Rather, it may lower a person's
inhibitions and make people more
talkative.
 Musician Jimi Hendrix died on
September 18, 1970 of a barbiturate
overdose. Marilyn Monroe also met
the same fate.
Opiates
3. Opiates: Opium and its
derivatives (morphine
and heroin) depress
neural activity,
temporarily lessening
pain and anxiety. They
are highly addictive.
Opiates
 Places on neurons recognize opiates. These receptors
are located in parts of the brain important for
breathing, pain, and emotions.
 The brain manufactures its own opiates known as
endorphins.
 Long history of opium use in medical field
Opiate History
 Important Dates in the History of Opiates
 1803 - Morphine was isolated from opium by Frederick Serturner.
1832 - Codeine was extracted from opium.
1874 - Heroin was first produced from morphine.
1898 - The Bayer Company introduced heroin as a substitute for
morphine.
1914 - Harrison Narcotic Act - Added a tax on opiate distribution.
1922 - Narcotic Import and Export Act - Restricted the
importation of crude opium except for medical use.
1924 - Heroin Act - Made manufacture and possession of heroin
illegal.
1930 - Federal Bureau of Narcotics was created.
1970 - Controlled Substances Act was passed - Divided drugs
into categories, set regulations and penalties for narcotics.
Heroin Effects on the Brain
 Stimulates a "pleasure system" in the brain involving
neurons in the midbrain that use the neurotransmitter
called "dopamine."
 Midbrain dopamine neurons project to the cerebral
cortex causing the pleasurable effects of heroin and
adding to the addictive power.
 Other neurotransmitter systems, such as those related
to endorphins also likely to be involved with
withdrawal from and tolerance to heroin.
Famous Opiate Abusers
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John Belushi (Death)
Kurt Cobain (Death)
Jerry Garcia (Death)
Edgar Allen Poe
Marilyn Monroe (Death)
Anna Nicole Smith
(Death)
 John Candy (Death)
 Ben Franklin
 Robert Downey Jr.
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Boy George
Elvis Presley (Death)
Jim Morrison (Death)
Tom Sizemore
Sid Vicious (Death)
Keith Richards
DJ AM (Death)
Heath Ledger (Death)
Chris Farley (Death)
Janis Joplin (Death)
Stimulants
Stimulants are drugs that excite neural activity and
speed up body functions.
1.
2.
3.
4.
5.
6.
Caffeine
Nicotine
Cocaine
Ecstasy
Amphetamines
Methamphetamines
Caffeine and Nicotine
Caffeine and nicotine increase heart and breathing
rates and other autonomic functions to provide
energy.
Amphetamines
Amphetamines stimulate neural activity, causing
accelerated body functions and associated energy
and mood changes, with devastating effects.
Amphetamine Effects on Brain
 Cause release of dopamine from axon terminals.
 Block dopamine reuptake.
 Inhibit storage of dopamine in vesicles.
 Inhibit destruction of dopamine by enzymes.
 Actions result in more dopamine in the synaptic cleft
where it can act on receptors.
Results of Amphetamine Use
 Insomnia, restlessness
 "Paranoid psychosis"
 Hallucinations
 Violent and aggressive behavior
 Weight loss
 Tremors
Crystal Meth
 Highly addictive amphetamine with effects similar to
cocaine.
 Synthetic (manmade) drug, manufactured locally
using pseudo-ephedrine (ingredient in cold
medications), acetone, drain cleaner, lithium, iodine,
paint thinner, kerosene.
 Damage to the brain is similar to that caused by
strokes or Alzheimer’s disease.
 20% of people who use meth become dependent.
Ecstasy
 Ecstasy or (MDMA) -
Stimulant and mild
hallucinogen.
 Produces euphoric high
 Can damage serotoninproducing neurons,
resulting in permanent
deflation of mood and
impairment of memory.
Ecstasy
Cocaine
Cocaine induces immediate euphoria followed by a crash.
Crack, a form of cocaine, can be smoked. Other forms of
cocaine can be sniffed or injected.
Long Term Effects of Cocaine
 Dizziness
 Headache
 Movement problems
 Anxiety
 Insomnia
 Depression
 Hallucinations
Hallucinogens
Hallucinogens are
psychedelic (mindmanifesting) drugs that
distort perceptions and
evoke sensory images in
the absence of sensory
input.
LSD
1. LSD: (lysergic acid diethylamide)- chemical that
alters a user's mood, thoughts or perceptions.
2. Thought that effects of LSD caused by
stimulation of serotonin receptors on neurons in
brain area called the raphe nuclei. Not clear
what produces all the effects of LSD.
3. Mandatory 5 year sentence for possession of 1
gram.
Effects of LSD
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Feelings of "strangeness"
Vivid colors
Hallucinations
Confusion, panic, psychosis, anxiety
Emotional reactions like fear, happiness or sadness
Distortion of the senses and of time and space
"Flashback" reactions - these are the effects of LSD that
occur even after the user has not taken LSD for months or
even years.
 Increases in heart rate and blood pressure
 Chills
 Muscle weakness
Mushrooms
 Psilocybin Mushrooms: produce s yawning, inability to
concentrate, restlessness, increased heart rate, and
hallucinations (visual and auditory
 Amanita Muscaria: produces feelings of euphoria,
hallucinations, muscle jerks, drowsiness, sweating, pupil
dilation, and increased body temperature. Toxic to kidneys
and liver.
Mushrooms Effects on Brain
 Chemical structure similar to serotonin
 Primary effect of psilocin is on seratonin receptors.
 Reduces reuptake of serotonin by neurons .
 Muscimol activates GABA receptors on neurons-
inhibitory system
Mushrooms
 Identification of hallucinogenic mushrooms can be
difficult because they look similar to toxic, deadly
mushrooms.
 Mushrooms bought from dealers may be contaminated
with drugs such as LSD or PCP
 In 1998 in the United States, 9,839 cases of mushroom
poisoning were reported by poison centers
 "All mushrooms are edible, but some only once."
-- Croatian Proverb
PCP
 Phencyclidine- affects multiple neurotransmitter
systems in the brain: inhibits reuptake of dopamine,
norepinephrine, serotonin, and inhibits action of
glutamate.
 Dissociative anesthetic because users appear to be
"disconnected" from their environment: they know where
they are, but they do not feel as if they are part of it =
violent/aggressive behavior
 Can act like many other classes of drugs depending on user
and administration
Cannabinoids
 Marijuana (Cannabis sativa)
 THC (delta-9-tetrahydrocannabinol): is the major active
ingredient in marijuana (hemp plant) that triggers a
variety of effects, including mild hallucinations.
Marijuana Effects on Brain
 THC acts on cannabinoid receptors on neurons in
brain.
 Brain areas involved in memory, concentration,
perception, movement.
 Impairs with normal functioning of these areas of the
brain.
Marijuana Effects on the Brain
 Anandamide is the brain's own THC (just like
"endorphin" is the brain's own morphine).
 THC can affect two neurotransmitters: norepinephrine
and dopamine. Serotonin and GABA levels may also be
altered.
Addiction/Death?
 Addiction is controversial.
 Also controversial is whether marijuana causes long-
term mental abnormalities.
 Future research needed.
 NO documented cases of a fatal overdose produced by
marijuana.
 High level of tar and other chemicals in marijuana;
smoking marijuana increases the chances of lung
problems and cancer later in life.
How long does marijuana stay?
 Marijuana can be detected in urine, blood, saliva, and
hair follicles.
 Depends on how much a person has smoked, how long
a person has smoked for, and the method used to
detect THC.
 The half-life of THC is about 24 hours. However, the
metabolites of THC can be detected for 45 to 60 days
after the last use.
Drug Use
The graph below shows the percentage of US highschool seniors reporting their use of alcohol,
marijuana, and cocaine from the 70s to the late
90s.
Influences on Drug Use
The use of drugs is based on biological,
psychological, and social-cultural influences.
Marijuana Use
The use of marijuana in teenagers is directly
related to the “perceived risk” involved with the
drug.
Near-Death Experiences
After a close brush with
death, many people
report an experience of
moving through a dark
tunnel with a light at the
end. Under the influence
of hallucinogens, others
report bright lights at the
center of their field of
vision.
Mind-Body Problem
Near-death experiences raise the mind-body issue.
Can the mind survive the dying body?
1.
Dualism: Dualists believe that mind (nonphysical) and body (physical) are two distinct
entities that interact.
2.
Monism: Monists believe that mind and body
are different aspects of the same thing.