Transcript Drugs and Consciousness

Drugs and
Consciousness
Drugs and Consciousness
Many of us take drugs on a pretty
regular basis. Some for medical
reasons (painkillers), some for
recreational reasons (alcohol) and
some just to get up in the morning
(caffeinated sodas). Although the
drug business is very complex and
there are literally tens of thousand
of drugs out there today; for the
most part they all have one thing in
common- they manipulate our
neurotransmitters.
Almost everything a drug does it does
by tricking our neurons into firing or
not firing neurotransmitters. If you
think about it, every feeling that
drugs give us, is really our natural
neurotransmitters in overdrive. If
you had REALLY good control over
your own body you could up your own
dopamine levels and feel like you are
on Crack without ever taking the
actual drug (actually, its not possible
and probably would not be healthy).
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Psychoactive Drugs
• Chemicals that have psychological
effects
– meaning that they change
perceptions, moods, thinking,
and behavior
– Sometimes called recreational
drugs, though some may have
legitimate medical uses
Types of Psychoactive Drugs
• Depressants
• Narcotics
• Stimulants
• Hallucinogens
Depressants – sedatives
• Calm neural activity and slow body
functions
– Downers – induces relaxation
• Alcohol, inhalants, barbiturates
(tranquilizers)
• Effects – relaxation, less anxiety
• Negative Effects – impaired
coordination (messes with
cerebellum) judgment and
memory, depression, mood
swings, drowsiness
Stimulants
• Temporarily excite neural activity and
arouse body functions – Uppers
• Amphetamines, caffeine, nicotine,
cocaine, ecstasy, and
methamphetamine (speed)
• Effects – excitation, confidence,
increased alertness
• Neg. Effects – anxiety, restlessness,
irritability, sleeplessness, increased
aggressiveness, feelings of panic,
paranoia (schizophrenia like
symptoms), even death from
overdose, extensive brain damage and
tissue loss
Effects of Stimulants
Stimulants
Smoking
Caffiene
Narcotics (Opiates)
• Pain reducers (analgesics)
• Depress the central nervous
system
• Mimic endorphins
• Codeine, heroin, morphine,
opium
• People take narcotics to
induce feelings of euphoria,
relieve pain, and induce sleep
• Very addictive and produce
terrible withdrawal
You on Drugs
Hallucinogens - psychedelics
• Distort perceptions and evoke
sensory images in the absence of
sensory input
– sights, sounds, and tastes that aren’t
actually there
• LSD, PCP, marijuana, ecstasy
• Effects – changed perceptions,
hallucinations, euphoria, relaxation,
increased awareness
• Neg. Effects – nausea, paranoia,
anxiety, mood swings, impaired
judgment, jumbled thoughts,
impaired memory, sluggishness
LSD PSA
What can influence the effects
of Psychoactive Drugs??
The amount and potency of the drug
How the drug is administered
How much previous experience a user
has with the drug
The user’s age and body weight
The user’s mood, personality, and
motivation
The environment in which the drug is
used
The user’s expectations about the
drug’s effects
How Psychoactive Drugs Work
• Psychoactive drugs work by
affecting neurotransmitter function
– Drugs can cause more or less of
a neurotransmitter to be released
into synapses
• (agonist)
– Drugs can stimulate or block
receptors
• (antagonist)
– Drugs can block the reuptake of a
neurotransmitter
• (reuptake inhibitor)
The Blood Brain Barrier ("Keep Out")
• Protects the brain from "foreign
substances" in the blood that may
injure the brain
– prevents materials from the blood from
entering the brain
– it allows some materials to cross, but
prevents others from crossing
– allows the entrance of essential nutrients
• The concept of the blood brain
barrier was first introduced by Paul
Ehrlich
– He found that intravenous injection of
dyes into the bloodstream stained all the
tissues in most organs except the brain.
Chronic Use of Psychoactive Drugs
• Tolerance
– with repeated exposure to a
psychoactive drug, the drug’s effect
lessons
– thus it takes bigger doses to get the
desired effect
• the user experiences
neuroadaptation
– the brain adapts its chemistry to
offset the drug effect
Chronic Use of Psychoactive Drugs
• Withdrawal
– what people experience when they
stop using a drug after a long period
of regular use
– the discomfort and distress that
follow discontinuing the use of an
addictive drug
• Different drugs produce
different kinds of withdrawal
symptoms
Withdrawal
Chronic Use of Psychoactive Drugs
Physical vs. Psychological Dependence
• Physical Dependence
– the body responds to the drugs absence and the
user may feel physical pain and intense cravings
• Psychological dependence
– a psychological need to use a drug, such as to
relieve negative emotions
• Addiction
– a craving for a substance despite adverse
consequences and often with physical symptoms
such as aches and nausea
Heroin Addicts
Drug Use Influences
So why take
drugs in the first
place??
Influence on Drug Use
• Biological
– genetic tendencies
– dopamine reward circuit
• a brain pleasure pathway
Influence on Drug Use
• Psychological
– Lacking sense of purpose
– Significant stress
– Psychological disorders such
as depression
Influence on Drug Use
• Social-cultural
– Urban environment
– Belonging to a drug using
cultural group
– Peer influences
Alcoholism is Not a Disease
Don’t Do Drugs!!!
Anti Drug Commercials