Diagram of psychoactive drugs

Opioids

Stimulants

Cannabinoids

Empathogens

Psychedelics

Dissociatives

Hallucinogens

Psychologically Addictive Psychoactive Drugs

Depressants (Sedative-Hypnotics)

Psychoactive Drugs' Interaction with Neurotransmitter Systems

Endogenous Opioid System

National Institute on Drug Abuse (NIDA) Resources

An individual is observed to have constricted pupils, slurred speech, and a significantly slowed breathing rate. They appear drowsy and disoriented. This specific combination of physiological and behavioral effects is most characteristic of which class of psychoactive substances?

Physical Dependence in Substance Use Disorders

Withdrawal in Substance Use Disorders

Psychologically Addictive Psychoactive Drugs

Psychological Dependence (Drug Craving) in Substance Use Disorders

A college student starts using a stimulant to help them study for exams. Initially, they only use it during finals week. However, they soon find themselves using it multiple times a week, even when they don't have exams, and in larger amounts than they originally intended. Their grades have started to drop, and their friends have expressed concern about their changed behavior and irritability. Despite these negative effects, the student continues to seek out and use the substance. Which of the following best explains this pattern of behavior?

Tolerance in Substance Use Disorders