A smokable form of cocaine that produces rapid, short-lived effects and carries a high risk of addiction.
Crack
An addictive substance in tobacco and many vaping products that acts on the nervous system and reinforces continued use.
Nicotine
The presence of both a mental health disorder and a substance use disorder; commonly called co-occurring disorders.
Dual diagnosis
Ethanol, the psychoactive substance in alcoholic beverages; a central nervous system depressant that affects judgment, coordination, and behavior.
Alcohol
A powerful stimulant that increases activity in the brain’s reward system and carries risks of addiction and serious cardiovascular effects.
Cocaine
A potent stimulant that increases central nervous system activity and has a high potential for addiction and serious health effects.
Methamphetamine
A plant and its products containing cannabinoids, including THC, which can alter mood, perception, memory, and coordination.
Cannabis
Taking or consuming alcohol, medications, or other drugs; use alone does not necessarily indicate misuse or a disorder.
Substance use
An older term often referring to substance use disorder. Physical dependence specifically means adaptation that can cause withdrawal when use stops and does not by itself establish addiction.
Substance (chemical) dependency
A return to substance use after a period of stopping or reducing use, indicating a need to reassess treatment and support.
Relapse
Choosing or maintaining nonuse of a substance, such as alcohol or another drug.
Abstinence
A reduced response to a substance after repeated use, so the same amount produces less effect or a larger amount is needed for a similar effect.
Tolerance
An older phrase for substances used in ways that cause harm or increase risk, including alcohol, prescription medications, and other drugs.
Abused substances
A dissociative drug that can cause detachment from oneself or surroundings, altered perceptions, and unpredictable behavioral effects.
Phencyclidine (PCP)
An older term generally referring to alcohol use disorder, involving difficulty controlling drinking despite significant problems or harm.
Alcoholism
An older term for substance use that causes harm or significant problems; current terminology uses substance misuse or substance use disorder, depending on the circumstances.
Substance abuse
A severe, potentially life-threatening form of alcohol withdrawal involving delirium, agitation, and marked physical instability; a medical emergency.
Delirium tremens (DTs)
Substances that substantially alter perception, mood, and thinking and may cause experiences of things that are not present.
Hallucinogens
A stimulant found in coffee, tea, some soft drinks, and other products that increases alertness and can interfere with sleep.
Caffeine
An imprecise term traditionally referring to opioids that relieve pain and may cause sedation; legal usage may include other drugs.
Narcotics
A medication used in alcohol use disorder treatment that interferes with alcohol breakdown, causing an unpleasant and potentially dangerous reaction if alcohol is consumed.
Disulfiram (Antabuse)
A name used for products containing synthetic cannabinoids, also called K2, whose unpredictable effects can cause severe illness. These products are not the same as cannabis.
Spice
An informal term for substances chemically created or modified to produce psychoactive effects, sometimes intended to evade drug restrictions.
Designer drugs
A temporary substance-related state involving changes in thinking, perception, behavior, coordination, or physical functioning.
Intoxication
The process of evaluating and managing intoxication and withdrawal as a substance leaves the body; it is one part of treatment rather than a complete treatment for addiction.
Detoxification
An opioid made from morphine that can produce euphoria, physical dependence, and potentially fatal respiratory depression.
Heroin
A treatable condition involving compulsive substance use or behavior despite harmful consequences and difficulty controlling it.
Addiction
Central nervous system stimulants that increase alertness and activity; some are prescribed for conditions such as ADHD or narcolepsy.
Amphetamines
In this context, a chemical that affects the brain or body, including alcohol, medications, and other drugs.
Substance
Becoming accustomed to repeated exposure. In older substance-use terminology, it described habitual use or psychological reliance and was distinguished from physical dependence.
Habituation
Volatile substances whose vapors are inhaled for mind-altering effects, such as certain solvents, aerosols, and gases.
Inhalants
A long-acting opioid medication used to treat opioid use disorder by reducing withdrawal and craving; it is also prescribed for certain pain conditions.
Methadone