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Drugs. What is a Psychoactive Drug?. Chemical substance that alters perceptions, mood, or behavior through their actions at the neural synapse Three most common psychoactive drugs: Caffeine Alcohol Nicotine Cause an altered state of consciousness. Drugs and Neurotransmission.
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What is a Psychoactive Drug? • Chemical substance that alters perceptions, mood, or behavior through their actions at the neural synapse • Three most common psychoactive drugs: • Caffeine • Alcohol • Nicotine • Cause an altered state of consciousness
Psychoactive Drugs and Synapses • Affect synapses and neurotransmitters in several ways: • Binding with receptors (agonists) • Blocking receptor site (antagonists) • Blocking neurotransmitter’s reuptake • Inhibiting action potentials
How Are Drug Effects Studied? • Carefully controlled conditions • Compare behavior before and after use of drug • Often use the double-blind procedure • No one knows who is taking the placebo and who is taking the drug • Tricky because: • Drugs affect different people differently • Drugs can affect the same person differently at different times
Psychoactive Drug Categories • Three different categories we study: • Depressants • Stimulants • Hallucinogens
1. Depressants • Drugs that reduce neural activity and slow body functioning • Includes alcohol, barbiturates (anything that ends in an “al”), and opiates (body’s own opiates = endorphins)
Affects of Alcohol • Effects: • Part of brain that controls inhibitions and making judgments • Perceptual-motor skills • Visual-spatial processing • Problem solving • Abstract reasoning • 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 • Can literally shrink the brain What areas of the brain is it affecting?
2. Stimulants • Drugs that excite neural activity and speed up body functions • Include: caffeine, nicotine, amphetamines, MDMA (ecstasy) 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 • Very addictive and does not stay in the body very long • Will reach the brain in 7 seconds releases epinephrine and norepinephrine diminishes appetite and boost alertness and mental efficiency • Just as quickly addictive as heroin and cocaine • Also stimulates the release of dopamine and natural opiates
Facts about Nicotine • Tobacco kills 5.4 million of its 1.3 billion consumers a year • A teen-to-grave smoker has a 50% chance of dying from the habit • If you don’t smoke by the time you get through your college years, you probably never will • Among teens whose parents and best friends are nonsmokers, the smoking rate is close to 0 • Half of all Americans who have ever smoked, quit
Methamphetamine • Temporarily triggers the release of dopamine (enhanced energy and mood) • Over time, will reduce the baseline dopamine levels in the body leaving the user with a depressed functioning
3. Hallucinogens • Distort perceptions and evoke sensory images in the absence of sensory input • Include: LSD and Marijuana • Albert Hofmann – creator of LSD
Marijuana • Gets to the brain in 7 seconds • Will linger in the body for a month or more • THC is a anandamide agonist • Triggers release of other neurotransmitters (dopamine, serotonin) • Alters sensory perception (cerebral cortex), effects movement, impact memory (hippocampus)
Biology, Psychological, and Social influences • Some people may be vulnerable to particular drugs • Drug use can be caused by psychological factors • Stress • Depression • Feelings of failure • Social influences • Young, unmarried, and have recently left home – more likely to use drugs • Married and have children, drug use decreases • Peers – also what adolescents think their friends are doing