Drugs and
Consciousness

Psychoactive Drug
 a chemical substance that alters perceptions
and mood

Physical Dependence
 physiological need for a drug
 marked by unpleasant withdrawal symptoms

Psychological Dependence
 a psychological need to use a drug
 for example, to relieve negative emotions
Dependence and
Addiction
Big
effect
Drug
effect

Tolerance
 diminishing effect
with regular use
Response to
first exposure

After repeated
exposure, more
drug is needed
to produce
same effect
Little
effect
Small
Large
Drug dose
Withdrawal
 discomfort and
distress that follow
discontinued use
Psychoactive Drugs

Depressants – “downers”
 drugs that reduce neural activity

alcohol, barbiturates, opiates
 slow body functions sympathetic NS
Psychoactive Drugs

Alcohol
 affects motor skills, judgment, and
memory
 reduces self awareness
 Disrupts processing of recent events
into long-term memories
 large amts – depressant,
small amts - stimulant
Animation - Alcohol
http://outreach.mcb.harvard.edu/animations/s
ynapse.swf
http://learn.genetics.utah.edu/content/a
ddiction/drugs/mouse.html
Psychoactive Drugs

Barbiturates
 tranquilizers, mimic effects of
alcohol
 drugs that depress the activity of
the central nervous system,
reducing anxiety but impairing
memory and judgment
Psychoactive Drugs

Opiates
 opium and its derivatives
(morphine and heroin)
 opiates depress neural activity,
temporarily lessening pain and
anxiety
 highly addictive
Animation - Heroin
http://outreach.mcb.harvard.edu/animations/s
ynapse.swf
http://learn.genetics.utah.edu/content/a
ddiction/drugs/mouse.html
Psychoactive Drugs

Stimulants – “uppers”
 drugs that excite neural activity

caffeine, nicotine, amphetamines,
cocaine
 speed up body functions –
nicknamed “speed”
Animation
Caffeine, Nicotine, Cocaine
http://outreach.mcb.harvard.edu/animat
ions/synapse.swf

http://learn.genetics.utah.edu/content/a
ddiction/drugs/mouse.html
Psychoactive Drugs

Amphetamines
 drugs that stimulate neural
activity, causing speed-up in
body functions and associated
energy and mood changes
 more powerful than cocaine
Psychoactive Drugs

Cocaine
 effects depend on dosage,
form, expectations, personality
and situation
(coca leaves, powder, crack )
 Blocks dopamine, serotonin,
norepinephrine – depression,
irritability
Cocaine Euphoria and
Crash
Psychoactive Drugs

Ecstasy
 MDMA
(methylenedioxymethamphetami
ne)
 stimulant and mild hallucinogen
 dangerous short and long term
effects
 Blocks the reabsorbtion of
serotonin, releases dopamine
Animation - Ecstasy
http://learn.genetics.utah.edu/content/a
ddiction/drugs/mouse.html
Psychoactive Drugs

Hallucinogens
 psychedelic (mind-manifesting)
drugs that distort perceptions
and evoke sensory images in
the absence of sensory input


LSD
MDMA (Ecstasy)
Psychoactive Drugs

LSD
 lysergic acid diethylamide, also as acid
 a powerful hallucinogenic drug
 chemically similar to serotonin and block it

THC
 the major active ingredient in marijuana
 triggers a variety of effects, including mild
hallucinations
 cognitive effects out last the use of the
drug
Animation - LSD
http://learn.genetics.utah.edu/content/a
ddiction/drugs/mouse.html
Near-Death
Experiences

Near-Death
Experience
 an altered state of
consciousness
reported after a close
brush with death
 often similar to druginduced
hallucinations
Psychoactive Drugs
Trends in Drug Use
Perceived Marijuana
Risk
Near-Death
Experiences

Dualism
 the presumption that mind and
body are two distinct entities that
interact

Monism
 the presumption that mind and
body are different aspects of the
same thing
Links

Meth Ingredients –
http://www.kci.org/meth_info/sites/Riverside_County.htm
Meth Epidemic – PBS Frontline Series
http://www.pbs.org/wgbh/pages/frontline/meth/body/#2