Transcript Module 22
Thinking About Psychology: The Science of Mind and Behavior Charles T. Blair-Broeker Randal M. Ernst Module 22 Drugs Module 22: Drugs Psychoactivity and Dependence Psychoactive Drug • A chemical substance that alters perceptions, mood, or behavior • Three common psychoactive drugs: – Caffeine – Alcohol – Nicotine • Induce an altered state of consciousness Dependence • A state of physiological and/or psychological need to take more of a substance after continued use. • Withdrawal follows if the drug is discontinued Dependence • Play “Brain Mechanisms of Pleasure and Addiction” (6:51) Segment #6 from The Mind: Psychology Teaching Modules (2nd edition). Withdrawal • The discomfort and distress that follow when a person who is dependent on a drug discontinues the use of the drug • Withdrawal symptoms are usually the reverse of the drug’s effects. Tolerance • Reduced responsiveness to a drug, prompting the user to increase the dosage to achieve effects previously obtained by lower doses of the drug Tolerance Module 22: Drugs Drugs and Neurotransmission Neurotransmission • The process whereby neurons communicate with each other • Neurotransmission, especially in the brain and spinal cord, helps explain the effects of psychoactive drugs. • Psychoactive drugs interfere with normal neurotransmission. Neurotransmitters • Chemical messengers that cross synaptic gaps between neurons • When released by the sending neuron, neurotransmitters travel across the synapse and bind to receptor sites on the receiving neuron, setting up the next link in the chain of communication. Synapse • The junction between the tip of the sending neuron and the receptor sites on the receiving neuron • Call the synaptic gap or cleft Neural Activity Neurotransmitters and the Synapse Reuptake • Process where the unused neurotransmitter chemical is reabsorbed by the sending neuron Reuptake Psychoactive Drugs and Synapses • Psychoactive drugs affect synapses and neurotransmitters in three ways: – Binding with receptors – Blocking receptor site – Blocking neurotransmitters’ reuptake Module 22: Drugs Drug Classifications Five Psychoactive Drug Categories • Five different categories we will study: – Depressants – Opiates – Stimulants – Hallucinogens – Marijuana Module 22: Drugs Drug Classifications: Depressants Depressants • Drugs that reduce neural activity and slow body functioning • Includes alcohol and sedatives Alcohol (ethyl alcohol) • Found in beer, wine, and liquor • The second most used psychoactive drug (caffeine first) • Slows thinking, and impairs physical activity Blood Alcohol Content (BAC) • A measure of how much alcohol is in a person’s bloodstream • BAC of .8 considered legal intoxication in most states Euphoric Affects of Alcohol • Alcohol impairs the parts of the brain responsible for controlling inhibitions and making judgments Alcohol, Memory, and Sleep • Studies have shown that alcohol impairs memory by suppressing the processing of events into long term memory. • Alcohol impairs REM sleep, further disrupting memory storage. Alcoholism and Heredity • Play “Alcohol Addiction: Hereditary Factors” (11:40) Segment #29 from The Mind: Psychology Teaching Modules (2nd edition). Sedatives • Drugs that reduce anxiety or induce sleep • Also called tranquilizers • Include barbiturates and benzodiazepines Barbiturates • Drugs that depress the activity of the central nervous system and thereby reduce anxiety • Can be lethal in overdose and interact with other drugs, especially alcohol • Impair both memory and judgment • Can create tolerance and dependence Benzodiazepines • Drugs that depress that activity of the central nervous system without most of the side effects associated with barbiturates • Include Valium and Xanax • Can create dependency Addiction and Depressants • Play “Depressants and Their Addictive Effect on the Brain” (4:24) Segment #22 from The Mind: Psychology Teaching Modules (2nd edition). Module 22: Drugs Drug Classifications: Opiates Opiates • Drugs that depress neural activity, temporarily lesson pain and anxiety • Include: opium, morphine, and heroin Morphine • Strong sedative and pain-relieving drug derived from opium • Works by preventing pain neurons from firing or releasing pain-signaling neurotransmitters into the synapse Endorphins • Natural, opiate-like neurotransmitters linked to pain control and to pleasure • Body’s natural pain killers Endorphins • Play “Endorphins: The Brain’s Natural Morphine” (5:01) Segment #5 from The Mind: Psychology Teaching Modules (2nd edition). Module 22: Drugs Drug Classifications: Stimulants Stimulants • Drugs that excite neural activity and speed up body functions • Include: caffeine, nicotine, amphetamines, and cocaine Caffeine • Stimulant found in coffee, chocolate, tea, and some soft drinks • Provides user with a sense of increased energy, mental alertness, and forced wakefulness • Blocks neurological receptor sites that , if activated, sedate the central nervous system Nicotine • Stimulant found in tobacco • Effects similar to those of caffeine • Very addictive and does not stay in the body very long Cocaine • Stimulant derived from leaves of the coca plant • Crack – cocaine crystals • Blocks the reuptake of certain neurotransmitters • Dependency is quick and severe; places extreme strain on cardiovascular system Amphetamines • Drugs that stimulate neural activity, speeding up body functions, with associated energy and mood changes • Includes: speed, uppers, and methamphetamines • Mimic adrenaline • Can cause irreversible changes in mood Module 22: Drugs Drug Classifications: Hallucinogens Hallucinogens • Drugs that distort perceptions and evoke sensory images in the absence of sensory input • Include: LSD and ecstasy • Sometimes called “psychedelics” Lysergic Acid Diethylamide (LSD) • • • • Powerful hallucinogenic drug Also known as “acid” The effects vary from person to person Users can be dangerous to themselves and others. Ecstasy • Hallucinogenic drug that produces lower inhibitions, pleasant feelings, and greater acceptance of others • Also called MDMA • Even moderate users may experience permanent brain damage. Module 22: Drugs Drug Classifications: Marijuana Marijuana • Leaves, stems, resin, and flowers form the hemp plant that, when smoked, lower inhibitions and produce feelings of relaxation and mild euphoria • THC (delta-9-tetrahydrocannabinol) is the active ingredient • Disrupts memory; lung damage from smoke Module 22: Drugs Prevention High School Drug Use (Johnston & others, 2002) Treatment • Play “Treating Drug Addiction: A Behavioral Approach” (19:40) Segment #30 from The Mind: Psychology Teaching Modules (2nd edition). The End