Transcript Overview Of Substance Use, Disorders And Harms

Overview of
substance use,
disorders and harms
© 2009 University of Sydney
Learning objectives
To develop an understanding of:
– Why people use drugs
– Prevalence
– Substance use diagnoses
– Aetiology
– The impacts of substance use on
public health
– Overview of public health
approaches for preventing and
reducing substance misuse
Case study
• Lisa, aged 18, presents to your
practice for contraceptive advice
• Lisa uses ecstasy tablets about twice a
year and is not at all concerned.
• Most of her friends do likewise, and
Lisa says she has not experienced any
harms
Questions about Lisa
• Why are so many young people using
ecstasy?
• Would you say her ecstasy use is a
problem?
Why do people use drugs?
• Two primary reasons:
– Pleasurable sensation
– Relief of discomfort (psychological
or physical)
• Secondary reasons:
– Because it is accepted
– Because it is not accepted!
Substance use in social
context
• Substances are often taken as
part of religious or social ritual.
Examples are:
– Drinking at a bar to ‘wind down’
after a week’s work
– Wine in Christian and Jewish
ceremonies
– Ecstasy taken at dance parties
– Coffee as a catalyst for meeting
for conversation or to enhance
work performance
• Moderate, controlled use is
accepted with minimal harms
Historical context
• Substance use is a consistent feature of most cultures:
• First opium use recorded on Sumerian tablet in 5000BC
• First brewery dates from 3500BC
• Patterns of drug use and social views change over time:
Use of some became illegal after
becoming problematic (cocaine, opiates,
cannabis)
Substances which are currently seen
as being harmful have not always
been seen that way
Some perspectives on
addiction
• Moral: a sign of weakness or evil
• Legal: an offence, which should be punished
to maintain law and order
• Public Health model: widespread practices
that influence the health of a nation
• Medical: dependence is a neurobiological
disease with psychosocial and medical
complications
• Social: cultural influences determine individual
behaviour
• Psychological: the influences of learning on
individual behaviour
Major drugs of abuse
Any drug that acts on the CNS to cause
pleasure can be abused:
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Alcohol
Nicotine
Cannabis
Opiates (licit and illicit such as heroin)
Sedatives
– especially benzodiazepines, such as Valium
• Stimulants
– amphetamines, cocaine, ecstasy
• Hallucinogens
• Others that may be abused: solvents,
antidepressants, antihistamines,
anticholinergics
Prevalence of substance
use in Australia
National Drug Strategy Household Survey 2007
GHB
Heroin
Inhalants
Tranquilisers
Cocaine
Alangesics
Hallucinogens
Ampethamines
Ecstasy
Cannabis
Any illicit
Tobacco
Alcohol
0
10
20
30
40
50
60
70
80
90
100
Percent
Ever used
Used in past 12 months
Australian Institute of Health and Welfare, 2008
Assessing prevalence and
patterns of drug use
• Household surveys of representative
samples
• Industry sales figures for alcohol, tobacco
and prescribed drugs
• Illicit Drug Reporting Scheme: uses
multiple sources of users and their
contacts
• Consequences: deaths, treatment seeking,
crime
When is drug and
alcohol use a problem?
What do we mean by saying a
person has a drug problem?
• A disorder of drug use is present
– Drug dependence (addiction)
– Harmful drug use
• Use of substance(s) without further
harms
– Not a diagnosis or medical disorder
– May not be socially accepted, be
stigmatised, or illegal
What do we mean by saying a
person has a drug problem?
The public’s understanding of drug and
alcohol problems is shaped by what is
visible, what is reported by the media and
individual experience.
Doctors’ opinions tend to resemble those
of the public but are also informed by
their professional training and
experiences.
What does a problem
drinker look like?
• Only a very small proportion of
heavy drinkers look like ‘park
bench’ alcoholics
International Classification
of Diseases (ICD)
• Intoxication
• Harmful use
• Dependence
Same criteria for alcohol, nicotine,
other psychoactive drugs
WHO, 2007
International Classification
of Diseases (ICD)
• Intoxication:
• Transient condition after use of a
substance leading to altered
consciousness, cognition or behaviour
• Harmful use:
Continuing use of the substance despite
evident harms related to substance use
What is dependence?
ICD-10
Dependence is a clinical syndrome
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•
Strong desire to use
Difficulties controlling use
Persistent use despite harm
Higher priority given to drug use than to
other activities/obligations (salience)
• Increased tolerance
• Physical withdrawal
Types of drinkers (adults)
5%
dependent
15%
hazardous or harmful
65%
low risk
15%
non-drinker
Teesson, 2000, ANZ J Psych, 34 (NSMHWB)
The prevention paradox
Hazardous and harmful drinkers
contribute more to the burden of
harm in the community than do
dependent drinkers, even though the
dependent drinkers have a more
severe problem.
This is because there are many more
people in the former category.
Natural history of
dependence
• Usually a lifelong disorder, with
remissions and relapses
• Some spontaneous remission
– 5% return to controlled drinking
– Most need to be abstinent to avoid
out-of-control drinking
Who develops drug-related
problems?
• A complication from an individual episode of
drug use
• Those who experiment too often and get
“caught”
• Those who try to “drown” their sorrows:
– childhood abuse, psychiatric disorders
– social disadvantage
• Prisoners
– (imprisonment may be the result or cause of
addiction)
• High risk occupations:
– military personnel, doctors, sales people,
hoteliers
• Ready availability of substance
Also non-environmental risk
factors for dependence
• Genetic (e.g. for alcohol)
– 4 x risk if father affected even if
reared apart
– Polygenic
• Psychiatric disorders
How does dependence
occur?
• Dependence-producing substance
– Psychoactive/rewarding
– Faster onset, more immediate reward
• e.g. parenteral administration
– Short duration of action: effect wears off
quickly
– Tolerance leading to increased use
• Individual vulnerability
• Availability
Neuroadaptation
Neuroadaptation is a core
neurobiological feature of addiction
Neuroadaptation
• The brain cells adapt to the chronic
presence of a psychoactive drug, so
that the person can function relatively
normally when intoxicated (tolerance)
– Involves a variety of cellular mechanisms
– Need higher doses of the drug to get the
desired effect
• When substance use ceases, the
person is then left in a state of
imbalance (withdrawal).
Extent and nature of drug
and alcohol problems
Global burden of disease
World Health Report 2002, WHO
Impact of substance misuse
on health in Australia
Collins & Lapsley, NDS monograph 66, 2008
Impact of substance
misuse in Australia, 2003
• Alcohol
– Harmful levels of drinking accounts for 3.2%
of Australia’s burden of disease
– Safe levels of drinking averts 0.9% of the
total burden
• Deaths from alcohol and illicits often occur
in younger people
• Tobacco accounts for 7.8% of the burden
of disease (the greatest disease burden)
• Tobacco causes more deaths, but later in
life
Begg et al, 2007, Australian Institute of Health and Welfare
Harm related to substance
use
Psychosocial
Physical complications may be related to:
• the substance itself
• route of use e.g. IV injection
• dependence
– Higher priority given to substance use
than health or diet
– Malnutrition
Harm related to substance
use
Personal
Physical health
Mental health
Social
responsibilities
Relationships
Family
Occupational
Legal
Social consequences
• Illicit nature
– (high cost, crime, impurity, injecting in
unsafe places/manners)
– Imprisonment in this population is as high
as 50%. (60% of prisoners are incarcerated
for drug-related crime)
Social consequences
• Illicit
• Stigmatised
– Alienation from parents, spouses and
children
– Discrimination in workplace, health care
– Stigma extends to those involved in D&A
services
Social consequences
• Illicit
• Stigmatised
• Finance : $50-200 per day
– Involvement in crime (theft, dealing,
importation)
– Prostitution
– Homelessness and debt to unscrupulous
drug dealers predispose this group to
becoming victims of violent crime.
– The combination of dependence and high
cost may lead to anti-social behaviour
(which is potentially reversible)
– Drained finances may lead to the loss of
necessities of life in favour of drug
procurement (which is an overpowering
physical and psychological need)
Social consequences
• Illicit
• Stigmatised
• Finance
• Intoxication
– Inability to complete education or maintain
paid employment
– user/parent unable to care for their children,
and family breakdown may result
Social consequences
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•
•
•
•
Illicit
Stigmatised
Finance
Intoxication
Vulnerability
– IDUs commonly also victims of crime:
homeless, intoxicated, disenfranchised
Medical complications
• Specific to drugs
• Related to injecting
• Contaminants
Physical harm from the
substance itself
– Acute
• intoxication (eg falls, motor
accidents, overdose, violence)
• specific side effects (eg myocardial
infarction related to cocaine)
– Chronic
• dependence
• specific chronic effects (eg alcohol
related liver disease)
Complications of IV route
• Vascular
damage
– Ischaemia
– Embolism
– Loss of veins
• Infections
– BBV
– Bacterial
– Fungal
Contaminants
A surprisingly uncommon cause of
illness
Recognised examples:
• Lead poisoning (found in some
amphetamine preparations)
• Talc (used to “cut” drugs down; toxic
to lung)
Why public health?
• Public health refers to the health of
the community
• Prevention efforts must be directed to
people who do NOT yet have the drug
problem.
– Interventions are directed to the
community, not just to affected people
• Drug-related harm is experienced by
non-users and first-time users as well
as habitual users
Two complementary
approaches
• Reducing or stopping drug use
Priority on cessation of drug use which will prevent
all adverse effects
• ‘Harm reduction’
Definition: refers to policies, programs, and
practices that aim primarily to reduce the adverse
health, social and economic consequences of the
use of legal and illegal psychoactive drugs without
necessarily reducing drug consumption. Harm
reduction benefits people who use drugs, their
families, and the community. (International Harm
Reduction Association, 2009 www.ihra.net)
Reducing drug use: supply vs
demand reduction
• Reducing drug use via reduced
supply
• Border controls
• Reducing production of drugs
• Punishment of dealers
• Reducing drug use via reduced
demand
• Education
• Treatment of dependent users
• Deterrence: e.g. imprisonment
The heroin drought
2000-2
What caused it?
• Local police heroin hauls?
• International factors: reduced exportation
from primary producers (Afghanistan war)
Effects
• Increase in users presenting for treatment
• Increase in alternative drug use (eg injected
temazepam, stimulants)
– Ischaemic limbs
– Stimulant induced psychosis
Harm reduction for IDUs
HIV prevalence in IDU
– New York City up to 50%
– Sydney 1%
Estimates
• Lifetime cost of HIV care = $100,000
• Drug users in Australia = 100,000
• Potential total life-time cost in
Australia = $10B!!
Harm reduction for IDUs
• Needle Syringe Programs (NSPs)
• Non-injecting route of administration (NIROA)
• Peer-education regarding safe injecting
• Medically Supervised Injecting Centre (MSIC)
• Decriminalisation?
• May lead to safer routes of use and hence
decrease the burden of disease and also
decrease health costs in a ‘market’ economy
Needle Syringe Programs
(NSP)
• Rapid outbreaks of HIV occur in cities
with and without NSP
• In regions lacking NSP, IDU is a
major mode of HIV transmission
• NSPs aim to provide enough sterile
equipment for each occasion of IDU
• Cost of NSP is 1% of the cost of no
NSP
Summary
• Humans are fascinated by mind altering
experiences, and also use drugs to
relieve suffering or anxiety
• Disorders of substance use may
develop
• Personal, social and legal barriers limit
drug use
• It is a challenge to develop rational and
evidence based policies because of
emotional and moral associations
Case study:
returning to Lisa
• Upon further enquiry:
– Lisa uses ecstasy at parties 2x a month
– Alcohol typically 10 wines on Fridays
• Drug related harms:
– Threatened with assault at a bar
– Unwanted sex while intoxicated without
injury or pregnancy
• You advise Lisa
– MDMA is illicit and pills are variable
– Encourage to reduce alcohol intake
Contributors
Associate Professor Kate Conigrave
Royal Prince Alfred Hospital & University of
Sydney
Professor Paul Haber
Royal Prince Alfred Hospital & University of
Sydney
All images used with permission, where applicable