Transcript Drugs and the Brain

The Science of Addiction
Agenda

What is Addiction??

Drug Classifications

Principles of Addiction Biology

Neurotransmitters

Cocaine Example
What is a Psychoactive Drug?

Chemical substance that acts on the CNS

Affects a person’s neurochemistry

Alters brain function
 Changes
in perception, mood, cognition,
consciousness, and behaviour
What is Addiction?

Abuse

Tolerance

Withdrawal

Dependence
The Three “C’s” of Addiction

Continued use of the drug in the face of
adverse consequences

Compulsion to use the drug with cravings
that the drug is necessary for functioning

A feeling/perception of being “out of
Control”
Psychoactive Drug Classifications

CNS Depressants

Cannabis

CNS Stimulants

Mixed Action

Opiates/Narcotics

Performance
Enhancers

Hallucinogens
DEPRESSANTS

ALCOHOL, SLEEPING PILLS, MINOR
TRANQUILIZERS (e.g.., Valium)

Used medically to induce sleep, relaxation,
and to relieve anxiety, decrease
inhibitions, slows down body functions

Some forms can be used as a “date-rape”
drug
ALCOHOL

THE LIVER CAN ONLY PROCESS ONE
STANDARD DRINK OF ALCOHOL PER HOUR

ONE STANDARD DRINK CONTAINS THE
SAME AMOUNT OF ALCOHOL =
1
341 ml/12 oz. can or bottle of beer (5% alcohol)
1
142 ml/5 oz. glass of wine (13% alcohol)
1
43 ml/1.5 oz. shot of hard liquor (40% alcohol)
FACTORS THAT INFLUENCE HOW A
PERSON REACTS INCLUDE:
weight – small person with lower body
weight will become more intoxicated than
larger person drinking same amount
 Body
– young people are still maturing and are
more sensitive to the effects of alcohol
 Age
Factors Continued…
of drinking – the body can only metabolize
one standard drink per hour
 Rate
– a full stomach slows the rate of absorption
into the bloodstream but a person can still
become intoxicated on a full stomach
 Food
– women are more susceptible because
they have less of the enzyme that breaks down
alcohol before it enters the bloodstream
 Gender
STIMULANTS

COCAINE, CRACK, AMPHETAMINES,
NICOTINE, METHAMPHETAMINES,
CAFFEINE, DIET PILLS

Increases in heart rate, energy, alertness,
decreases in appetite, speeds up body
functions

Reduced need for sleep
Nicotine

Nicotine is one of more than 4,000 chemicals
found in the smoke from tobacco products

Nicotine is the primary component in tobacco
that acts on the brain, the component that
causes addiction.

The addictive potential of nicotine is similar to
cocaine or heroin and greater than alcohol.
NARCOTIC/OPIATES

MORPHINE, CODEINE, HEROIN,
PRESCRIPTION PAIN KILLERS (e.g., demerol,
oxy contin)

Drowsiness, intoxication followed by euphoria,
relief from pain, slowed breathing

Route of use affects how quickly the user feels
the effects

High potential for abuse and dependency
HALLUCINOGENS

LSD (ACID), PSILOCYBIN (MAGIC
MUSHROOMS), MESCALINE

Mind altering, intensification of senses,
hallucinations (see, hear, feel), distortions
in time and distance, rapid mood swings,
confusion
MIXED ACTION

ECSTACY, PCP, INHALANTS

May act as a stimulant, hallucinogen,
depressant, or any combo-depends on the
amount taken

Hallucinations, increases in heart rate, blood
pressure, distorted body image, feelings of
euphoria

Effects of high doses can be serious and
unpredictable
PERFORMANCE ENHANCERS

STERIODS

Physiological and psychological effects

Enlargement of muscles, mood changes,
weight gain, growth pattern changes,
decrease in impulse control, increase in
aggression
CANNABIS

MARIJUANA, HASHISH, HASH OIL

Most widely used illegal drug

Mood-altering, feelings of euphoria,
enhanced senses, increases in heart rate,
distortions in perception of time and
space, difficulty with coordination and
reaction time
CANNABIS

All forms of cannabis contain
TETRAHYDROCANNABINOL (THC)

THC is the active ingredient in CANNABIS

Traces of THC can stay in the system for 30 days after
last use

Short-term memory loss and impairment of learning

Amotivational syndrome – loss of interest and motivation
for school, sports, etc.
Addiction Biology

Drugs activate the pleasure-producing chemistry
of the brain

Overstimulation of pleasure pathways cause
them to neuroadapt

Once adaptation occurs
 Cessation
of the drug leads to withdrawal
 Difficulty deriving pleasure from previously enjoyed
activities
What neurotransmitters are
involved in drug use??
Neurotransmitters involved in Drug Use

Dopamine

Serotonin

Gamma Aminobutyric Acid (GABA)

Norepinephrine
Neurotransmitters & Drugs

Dopamine
 Cocaine,

Serotonin
 Alcohol,

Amphetamines, Opiates, Marijuana, Heroin
LSD, Ecstasy, Stimulants
GABA
 Depressants,

Marijuana
Norepinephrine
 Stimulants,
Marijuana
QUESTIONS?
Current Trends in Substance Use
Nova Scotia Student Drug Survey (2007)
• Surveyed
• Grades
4,486 students
7-12 (15.1 yrs)
• Self-report
questionnaire
• Confidential
• Random
and anonymous
sample
Substance
1991 1996 1998 2002 2007
(%) (%)
(%)
(%) (%)
Alcohol
Cannabis
Cigarettes
Psilocybin
LSD
Inhalants
Ecstasy
Cocaine or Crack
50.6
17.2
26.0
4.0
7.1
9.6
n/a
2.5
54.1
32.1
34.9
8.3
12.4
7.2
n/a
3.6
56.7
37.7
36.1
10.7
10.1
7.0
n/a
4.7
51.7
36.5
23.2
12.2
5.5
4.9
4.4
3.9
51.7
32.4
16.2*
7.7*
3.7
4.4
6.9*
4.3