The shared language for this course. Every lesson uses these words the
same way. When a term is italicized in a lesson, its meaning
lives here.
The spectrum of use
Substance use
Taking alcohol or a drug at all. Use is not automatically a problem — it sits at
one end of a spectrum. Avoid: "using" as a synonym for
addiction.
Substance misuse
Using a substance in a way that risks harm — too much, too often, in a risky
situation, or a medication used other than prescribed.
Avoid: abuse (as a casual synonym), recreational use.
Substance abuse
The course title's everyday term for a pattern of misuse that is causing harm to
health, relationships, work, or the law. Clinically this now falls under substance
use disorder. Avoid: "junkie," "addict" as labels for a
person.
Substance use disorder (SUD)
The medical diagnosis for problem use, scored on the 11 criteria and rated
mild (2–3), moderate (4–5), or severe (6+). It is a treatable
health condition, not a character flaw.
Avoid: "addiction" as the formal term — that word means
severe SUD here.
Spectrum (continuum)
The idea that use runs from no use → low-risk use → misuse → disorder, with no
sharp line. People move both directions along it.
How substances change the body & brain
Reward pathway
The brain circuit (centered on the basal ganglia) that releases
dopamine to make survival activities — eating, connection — feel good. Drugs
hijack it, flooding it far past natural levels.
Dopamine
A brain chemical that signals "that mattered — do it again." Drugs spike it, which
is why the brain learns to crave the drug over everyday rewards.
Tolerance
Needing more of a substance to get the same effect, because the brain has adapted.
One of the pharmacological 11 criteria.
Withdrawal
Physical and emotional symptoms when a substance the body has adapted to is
reduced or stopped. Also one of the pharmacological criteria.
Physical dependence
The body adapting so it needs the substance to feel normal (shown by tolerance and
withdrawal). Can happen with prescribed medicine and is not the same as
addiction.
Addiction
In this course, the everyday word for severe substance use disorder:
compulsive use that continues despite clear harm. It involves dependence plus
loss of control. Avoid: using "addiction" for any use at
all.
Craving
A strong urge or desire to use. Added to the diagnostic criteria in DSM-5 because
it drives relapse.
Measuring & assessing
Standard drink
A fixed unit of alcohol — 0.6 fl oz (14 g) of pure alcohol — so different drinks
can be compared. Roughly: 12 oz regular beer = 5 oz wine = 1.5 oz spirits.
Screener
A short self-assessment questionnaire (e.g. AUDIT for alcohol,
DAST-10 for drugs) that flags risky use. A screener suggests "look closer" — it
is not a diagnosis.
The 11 criteria
The DSM-5 checklist used to diagnose SUD, grouped in four domains: impaired
control, social impairment, risky use, and pharmacological (tolerance + withdrawal).
Changing & recovering
Stages of change
A model of how people actually change a behavior: pre-contemplation →
contemplation → preparation → action → maintenance (with relapse as a common detour).
You can be at different stages on different days.
Trigger
A person, place, feeling, or situation that sets off a craving or a return to use.
Naming your triggers is the first step to planning around them.
Relapse
Returning to use after a period of stopping. Treated here as a normal, expected
part of a chronic condition — a signal to adjust the plan, not proof of failure.
Recovery
The ongoing process of changing the pattern and building a life where the
substance no longer runs the show. Not a single finish line.
The program
Diversion program
A voluntary alternative to normal prosecution for eligible people (often
first-time, non-violent). Completing it — including this course — can let a person
avoid a criminal record.