HSCI 402
Substance Use, Addiction & Public Health
Dr. Milad Parpouchi
Week 8
October 25, 2024
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Outline
• Icebreaker
• Reminder: Group project part 1 due tonight @11:59pm
• Final exam has been scheduled!
• Instructions for Parts 3A, 3B, and 4 of group project
• DPPG Chapters 1 and 2
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Icebreaker
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Final exam has been scheduled!
• Final exam date, time, and location:
◦ Date: Sunday, December 8, 2024
◦ Time: 3:30PM – 6:30PM
◦ Location: SWH (Saywell Hall) 10041
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Group Project Instructions: Parts 3A, 3B, and 4
• Instructions have been posted to Canvas
• Let’s go over the instructions
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Why drug policy matters
• Psychoactive drug use among humans dates back thousands of years - it remains
common in most parts of the world… despite extensive efforts to prevent, eliminate, or
control it
• Many people use drugs (recreationally, problematically), and there are many reasons why
they do so…
• Illicit drugs and drug markets have important individual and societal impacts
• There is a need for effective policy measures that reduce drug-related violence, disease
and suffering…
• … but these efforts can produce unintended consequences which are sometimes as
serious as the problems they seek to solve
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What have you heard/do you know about
Portugal’s Drug Strategy?
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iClicker Question
Are you here today?
A) Yes
B) Yes, but in and out of sleep
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Definition of drug policy
Drug policy as a field of government is over 100 years old
Defined as:
◦ Government-developed laws and programs intended to influence whether or not people
use substances (and affect the societal/individual consequences of use)
• National drug policy consists of the above laws and programs
◦ Laws usually prohibit or regulate the possession, use, distribution, and production of
substances (and set penalties for violations)
◦ Also control the medical prescription of certain drugs, and impose penalties for breaking
regulations
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Definition of drug policy
3 areas of contemporary drug policy
◦ 1 – Programs to prevent initiation of drug use among non-users (prevention)
◦ 2 – Health and social services designed to help people who use drugs
reduce/stop their use, or minimize harmful consequences
(interventions/programs)
◦ 3 - Laws, regulations, initiatives intended to control the supply of illegal drugsincluding diversion/use of prescription drugs for non-medical purpose (control
measures)- *National/international elements present in this third area but not in
areas 1 and 2 above
• Also: government sponsorship of scientific research, program evaluations, and
monitoring initiatives- a growing component of drug policy responses
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Question: Why are most psychoactive drugs illegal?
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Illegal drugs
Why are drugs illegal?
Laws and regulations seek to make society safer and reduce drug use and drugrelated harms
Big questions of drug policy:
• How effective is this approach?
• What other approaches may have potential to achieve these goals?
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Illegal drugs
In most countries globally, non-medical use of psychoactive substances is illegal
◦ *exception is cannabis, which is increasingly regulated in many settings
A common approach but it denies governments the ability to use the policy levers of
regulation and taxation – (key in regulating/managing alcohol and tobacco)
• Illegal drug markets are unregulated- distributing drugs without quality or purity
controls (e.g., fentanyl contamination)
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Evidence regarding drug policy
• Can science inform the development of drug policy?
• Yes!
• But drug policy is heavily shaped by political processes, religious values,
cultural norms, and social traditions
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Terminology
• Psychoactive drugs- defined as a substance capable of influencing brain
systems linked to reward and pleasure- “drug” for simplicity
• People who use drugs (PWUD): person-centred, descriptive, neutral
• People who inject drugs (PWID): injection as mode of administration
• “Drug use”: transparent, neutral, and free of judgement: includes approved or
disapproved forms of consumption
• (Illicit) drugs: controlled/prohibited substances (heroin, cocaine, etc.) and
diverted pharmaceuticals (prescription opioids)
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Terminology
• Drug misuse, harmful use or problematic use: consumption that causes social,
psychological or health problems/harms for individual or society
• Drug dependence: psychobiological syndrome involving impaired control of use,
increased tolerance, continued use despite negative consequences, and
withdrawal symptoms – has replaced “drug addiction” in the ICD
• Drug-related problems: social, legal, psychological, medical consequences
stemming from drug consumption
• Note: all the above terms are not referring to alcohol or nicotine - fundamentally
different from a policy perspective due to legality
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Chapter 2: Matters of Substance
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Substances
3 dimensions to consider in relation to each substance:
1: Natural, semi-synthetic, or synthetic
2: Route of administration
3: Medicinal or non-medicinal use
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Substances
1) Natural, semi-synthetic, or synthetic
Modern chemistry has led to:
• Natural: production of potent extracts (morphine, cocaine, etc.)
• Semi-synthetic drugs (e.g., oxycodone)
• Synthetic forms of drugs (Fentanyl, MDMA)
◦ New or more potent substances (LSD, benzodiazepines, etc.)
◦ Synthetic pain medications (fentanyl, carfentanil)
• Trend toward increased potency, portability (due to purity/concentration) and
dependence potential in the evolution of substances
• Example: fentanyl and carfentanil = increasingly potent opioids
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iClicker Question
Heroin is a _________ drug.
A) Natural
B) Semi-synthetic
C) Synthetic
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Substances
2) Route of administration (how they are ingested)
• Taken orally
• Insufflated (‘snorted’) intake via mucous membranes in nasal passages (e.g.,
cocaine)
• Inhalation- smoking or vaporizing (cannabis, crack, crystal meth, etc.)
• Via injection – intravenous, intramuscular or subcutaneous injection (heroin,
cocaine, etc.)
Trend toward more rapid delivery/effects
Injection: Increasing potential for misuse, dependence, and harm
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Substances
3) Whether or not the substance has an accepted medicinal use
• Many substances originally developed for medical purposes but…
• …now restricted under prescription system (sedatives, opioids)
• Some are still medical, but strictly controlled (morphine, amphetamines,
benzodiazepines)
• Others no longer regarded to have medicinal purposes (cocaine, heroin)
Medicinal substances are often misused (potential for physical, psychological, or
legal problems)
• Used by people who have not been prescribed them
• Used for reasons other than their medical purpose
• Taken in larger doses than intended
• Taken through other routes of administration (snorted, injected)
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Substances
3 dimensions to consider in relation to each substance:
1) natural/semi-synthetic/synthetic; 2) route of administration; 3)medicinal/nonmedicinal use
These distinctions are crucial but not sufficient to fully comprehend the complexities
of drug use
Must also consider the diversity, role, and specific risks of:
• Different consumption patterns
• Effects of drug combinations (e.g. overdose)
• Situational risks (e.g. driving under the influence)
• Behavioural risk taking (e.g. unprotected sex during the high experienced after
amphetamine use)
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Drug availability
Availability: has crucial implications for increasing/decreasing patterns of use of a
substance in terms of
◦ Supply of drugs (physical availability)
◦ Cost (economic availability)
◦ Attractiveness (psychological availability)
◦ Social acceptance within an individuals’ networks (social availability)
• As a substance becomes more physically available, affordable, attractive (as
reinforcer and a social symbol), and accepted among one’s peers - the more likely
experimentation and continued use will occur
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Substance Dependence / Substance Use Disorder
ICD-11 focuses on 3 criteria (any 2 quality as a diagnosis of substance
dependence):
◦ Impaired control over substance use;
◦ Substance use becoming an overriding priority in the person’s life
◦ Physiological tolerance, withdrawal symptoms, repeated use to alleviate
withdrawal from the drug
• DSM-5; abuse/dependence replaced with substance use disorder, diagnosed on
presence of 2/11 criteria related to use (discussed earlier in the semester – alcohol
use disorder)
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How do drugs cause harm
Health harms through:
• Intoxication (accidents, violence, injury)
• Acute Harms (drug-induced psychosis, overdose)
• Chronic Harms (long term use à organ damage)
• Dependence or substance use disorders (leads to prolonged use in a high risk
pattern)
• Social problems (unemployment, partner/child abuse)
• Indirect harms (incarceration for drug offences)
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Mechanisms of harm
Risks of a specific substance vary in relation to the:
• Dose
• Drug use pattern (amount & frequency)
• Route of administration
3 mechanisms:
• Toxic/biochemical effects
• Psychoactive actions producing intoxication
• Dependence
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3 aspects of use shaping risk/harm
• Dose: ranges from barely intoxicating to lethal and is related to purity
◦ Greater doses increase potential for acute effects like intoxication or overdose
• Pattern of use: (frequency/amount/variability of consumption) - may be
intermittent (e.g., weekends) or daily
• Mode of administration: non-oral routes may have potential for infectious disease
transmission, and increased risk of overdose
• Dose can exceed tolerance leading to toxic effectàoverdose or death
• Regular use can lead to chronic effects on tissues/organs - heavy cannabis use
can lead to lung conditions
• Intoxication: impaired judgement/coordination and potential for injuries
◦ Can also contribute to panic, disorientation, violence, and medical/psychological
problems
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The influence of context
Key mediators (i.e., toxic effect, intoxicating effect, and dependence potential) can
be affected by contextual factors:
◦ Expectations of the user
◦ Setting drug is used
In a familiar/supportive setting a drug may produce enjoyable experiences
In an unfamiliar or threatening setting a drug may produce a panic reaction
• Some social harms (e.g., unemployment) may result from both the drug itself and
the social context (including society’s reaction to drug use)
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Relative harm of different substances
Key question for public policy: How serious is the risk of harm resulting from use of
different substances?
• Implicit assumption in policy- drugs that are more risky or harmful require more
control and monitoring
International drug control conventions are based expert committee
recommendations regarding a drug’s ‘liability to abuse [constituting] a risk to public
health’
Regulations differentiated by degree of risk for social and health problems/harms
• UK- Class A, B, C
• Numerous attempts by researchers to characterize substances in terms of relative
potential for harm considering modifying factors (route of administration, context of
use) that may increase/decrease risk
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• This is one approach:
• Alcohol has greatest potential for
harm
• Tobacco, heroin, and marijuana have
fewer direct adverse health effects
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Relative harm of different substances
Another dimension: likelihood of an overdose, based on estimates of a ”safety
ratio” – based on “dose” (Gable 2004; Gable 2006)
◦ Most toxic substances (e.g. heroin, GHB): were determined to have a lethal dose
less than ten times the dose most commonly used for non-medical purposes
◦ Heroin via injection had a safety ratio of 5
◦ Oral stimulants and for alcohol: 10
◦ Intranasal cocaine: 15
◦ MDMA: 16
◦ Cannabis via smoking: over 1000
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Relative harm of different substances
• Another approach: Margin of
Exposure (MoE) paradigm
(Lachenmeier and Rehm, 2015)
• Ratio of the toxicological threshold
(benchmark dose) and estimated
human intake dosage
• Figure on the right is for daily use
among those tolerant
◦ Alcohol = highest risk category
(<10)
◦ Only THC and diazepam outside
“medium risk” category (MoE >100)
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Relative harm of different substances
• Another dimension: Dependence potential – propensity of a substance to result in
dependence
• Expressed as a drug’s capture ratio- the proportion of users who develop
dependence on that substance (Gable 2006)
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Relative harm of different substances
• A global approach to dangerousness was developed by French expert committee
(Roques, 1999)
Rated seven substances on general toxicity and social dangerousness
• Toxicity includes long-term health effects (cancer and liver disease), infections
(and other injection-related consequences), and acute effects (represented by the
safety ratio)
• Social dangerousness focuses on aggressive and uncontrolled conduct stemming
from use of the drug
• Heroin and alcohol rank relatively high on all 4 dimensions of dangerousness
• Marijuana scores the lowers; other drugs vary dependent on criteria
• Tobacco high on toxicity, low on dangerousness
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• Nutt et al. (2010) led comprehensive attempt to estimate harm associated with
psychoactive substances based on expert ratings of 16 harm criteria, including:
◦ Physical damage
◦ The tendency of the drug to induce dependence (harm to individual)
◦ The effect of drug use on families, communities, and society (harm to others)
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This rating system and analysis highlights limitations of conventional classification
of drugs into high, medium, and low categories of harm used as the basis for
criminal penalties, policing, prevention, and treatment programmes
Inconsistencies:
• Most harmful drug is legal and widely available
• Some less harmful drugs are illegal or subject to strict penalties
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Relative harm of different substances
Another examination (van Amsterdam et al. 2015) based on an expert panel method
assessed the harm of 20 drugs from an EU perspective
◦ Used methods similar to Nutt et al., (2010), but included specific information
about local factors.
◦ Figure 2.3 illustrates the consensus ratings from high to low harm.
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Relative harm of different substances
Numerous attempts using different approaches and methods- but substantial
agreement between the different rankings (Nutt et al. 2010; van Amsterdam et al.
2015).
• Heroin, cocaine, tobacco, and alcohol are rated to produce more harm
• Khat and betel nut (two plant-based stimulants) and cannabis are ranked to be
less harmful
• These ratings do not compare the overall levels of harm from different drugs in a
population, which relates to prevalence and volume of use in the population
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iClicker Question
There are more people experiencing cannabis dependence than cocaine
dependence.
A) True
B) False
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Relative harm of different substances at
population level
Harm due to substance use has been calculated by epidemiologists according to
the prevalence of use of a substance, as well as the relative risks associated with its
use (Ezzati et al. 2004)
◦ Even substances with relatively lower risks to the average user can create
considerable harm if they are used with higher prevalence
◦ Although cannabis has a lower risk for dependence, because its use prevalence
is much higher than cocaine in most countries, there are more people with
cannabis dependence than with cocaine dependence (Degenhardt et al. 2013;
Whiteford et al. 2013)
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Drug harms
• Rating systems estimating risk or harm indicate that legal substances (alcohol,
tobacco) are at least as dangerous as many illegal substances
• Risks associated with each substance vary according to the drug’s health effects,
safety ratio, intoxicating effect, general toxicity, social dangerousness, dependence
potential, environment/context of use, and social stigma
• It’s complex
• Chemical properties of a substance are only one factor among many that
determines the potential for harm
• Drug policy must reflect the social and pharmacological complexities of
substances and the relative difference among them
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Thank you!
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