Hockenbury Discovering Psychology 5th txtbk

Psychoactive Drugs171The StimulantsCaffeine, Nicotine, Amphetamines, and CocaineKey Theme• Stimulant drugs increase brain activity, while the psychedelic drugs createperceptual distortions, alter mood, and affect thinking.Key Questions• What are the general effects of stimulants and the specific effects ofcaffeine, nicotine, amphetamines, and cocaine?• What are the effects of mescaline, LSD, and marijuana?• What are the “club drugs,” and what are their effects?tranquilizersDepressant drugs that relieve anxiety.opiates(OH-pee-ets) A category of psychoactivedrugs that are chemically similar to morphineand have strong pain-relieving properties.stimulantsA category of psychoactive drugs thatincrease brain activity, arouse behavior, andincrease mental alertness.caffeine(kaff-EEN) A stimulant drug found in coffee,tea, cola drinks, chocolate, and many overthe-countermedications.Stimulants vary in the strength of their effects, legal status, and the manner inwhich they are taken. All stimulant drugs, however, are at least mildly addicting, andall tend to increase brain activity. We’ll first look at the most widely used and legalstimulants, caffeine and nicotine. Then we’ll examine much more potent stimulants,cocaine and the amphetamines.Caffeine and NicotineCaffeine is the most widely used psychoactive drug in the world and isfound in such common sources as coffee, tea, cola drinks, chocolate, andcertain over-the-counter medications (see Table 4.5). Caffeine promoteswakefulness, mental alertness, vigilance, and faster thought processes bystimulating the release of dopamine in the brain’s prefrontal cortex.Caffeine also produces its mentally stimulating effects by blockingadenosine receptors in the brain. Adenosine is a naturally occurring compoundin your body that influences the release of several neurotransmittersin the central nervous system. As noted earlier, adenosine levels graduallyincrease the longer a person is awake. When adenosine levels reacha certain level in your body, the urge to sleep greatly intensifies. Caffeinestaves off the urge and promotes alertness by blocking adenosine’s sleepinducingeffects (Roehrs & Roth, 2008). Caffeine’s adenosine-blocking ability hasanother effect—it stimulates indirect and mild dopamine release in the brain’s rewardsystem.Table 4.5Caffeine and Conversation People enjoy acup of coffee or an espresso at the CafeArtigiano in Vancouver. In all its differentforms, caffeine is the most widely usedpsychoactive drug in the world (Juliano &Griffiths, 2004).Common Sources of CaffeineMilligramsItemCaffeineCoffee (short, 8 ounces) 85–250Coffee (grande, 16 ounces) 220–550Tea (8 ounces) 16–60Chocolate (semisweet, baking; 1 ounce) 25Soft drinks (12 ounces) 35–70Energy drinks (8 ounces, Red Bull, Jolt) 40–80Caffeinated waters (8 ounces, Water Joe, Java Water) 25–60Over-the-counter stimulants (NoDoz, Vivarin) 200Over-the-counter analgesics (Anacin, Midol) 25–130Over-the-counter cold remedies (Triaminicin, Coryban-D) 30Source: National Sleep Foundation (2004).