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This lesson dives into the neuroscience behind psychoactive drugs, exploring how substances like alcohol, cocaine, opioids, and caffeine don't create new sensations — they exploit the brain's own neurotransmitter systems. Drawing from Section 4.5 of OpenStax Psychology 2e, the discussion moves from the DSM-5 diagnostic framework for substance use disorder all the way through the biology of dependence, withdrawal, and the ongoing opioid epidemic. Whether you're studying for an exam or just curious about how a morning cup of coffee chemically blocks your sense of fatigue, this deep dive has you covered. In this video: • DSM-5 criteria for substance use disorder: compulsion, tolerance, withdrawal, and the key distinction between physical and psychological dependence • Depressants (alcohol, barbiturates, benzodiazepines) as GABA agonists — how chloride ions hyperpolarize neurons and why withdrawal can be life-threatening • Stimulants and the dopamine system: cocaine blocks reuptake while amphetamines reverse transporters to force-dump dopamine into the synapse • The ADHD paradox: why stimulant medications target the underactive prefrontal cortex and basal ganglia to reduce hyperactivity • Caffeine as an adenosine antagonist — illustrated by a 2012 case study of a woman consuming 3 liters of caffeinated soda daily • The anatomy of the opioid epidemic: from 1990s pharmaceutical marketing of OxyContin as non-addictive, to black-market heroin laced with fentanyl, to 130 U.S. deaths per day by 2019 • Hallucinogens (LSD, mescaline, PCP, ketamine) and the legal bottleneck blocking large-scale medical marijuana research #OpenStax #Psychology #Neuroscience #SubstanceUse #OpioidEpidemic OpenStax Content adapted from "OpenStax Psychology 2e", by OpenStax licensed under CC BY 4.0. Content based on Web Version: Apr 23, 2026. Read the textbook online https://openstax.org/details/books/psychology-2e Music first girl talking to me. by ikkun (ex. Barradeen) | https://soundcloud.com/ikkunwastaken Royalty Free Music by https://www.free-stock-music.com Creative Commons / Attribution-ShareAlike 3.0 Unported (CC BY-SA 3.0) https://creativecommons.org/licenses/by-sa/3.0/deed.en_US
Answer each question based only on what was presented in the video lesson. No outside knowledge is required — every answer can be found in the content covered during the deep dive.
Answer each question using what you learned in the video. Show your reasoning where asked, and use specific neuroscience vocabulary from the lesson.
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