1.3b The Neuron and Neural Firing: Substance Use Disorders and Psychoactive Drugs

psychoactive drug

a chemical substance that alters the brain, causing changes in perceptions and moods

substance use disorder

a disorder characterized by continued substance use despite resulting life disruption

depressants

drugs that reduce neural activity and slow body functions

tolerance

the diminishing effect with regular use of the same dose of a drug, requiring the user to take larger and larger doses before experiencing the drug’s effect

addiction

an everyday term for compulsive substance use that continue despite harmful consequences

—sometimes used for dysfunctional behavior patterns like out-of-control gambling

withdrawal

discomfort/distress after discontinuing an addictive drug/behavior

❌barbiturates

drugs that depress the central nervous system activity, reducing anxiety but impairing memory/judgment

opioids

opium and its derivatives; they depress neural activity, temporarily lessening pain/anxiety

stimulants

drugs that excite neural activity and speed up body functions

hallucinogens

psychedelic drugs that distort perceptions and evoke sensory images in the absence of sensory input

near-death experience

an altered state of consciousness reported after a close brush with death (like cardiac arrest); often similar to drug-induced hallucinations