Hockenbury Discovering Psychology 5th txtbk

172 CHAPTER 4 Consciousness and Its Variations© Universal Press Syndicate. Reprintedwith permission. All rights reserved.Yes, coffee drinkers, there is ample scientific evidence that caffeine is physically addictive.However, because the brain reward effects of caffeine are mild, coffee junkiesare not likely to rampage the nearest Starbucks and take hostages if deprived of their favoriteespresso. However, they will experience withdrawal symptoms if they abruptlystop their caffeine intake. Headaches, irritability, drowsiness, and fatigue can last a weekor longer (Juliano & Griffiths, 2004; Reissig & others, 2009).Taken to excess, caffeine can produce anxiety, restlessness, and increased heart rateand can disrupt normal sleep patterns. Excessive caffeine use can also contribute to theincidence of sleep disorders, including the NREM parasomnias, like sleepwalking(Cartwright, 2004). Recall that Scott, whose story we told in the Prologue, had beentaking caffeine pills for several weeks before his sleepwalking episode. Because Scottnever drank coffee or other caffeinated beverages, his caffeine tolerance would havebeen low. Especially when combined with sleep deprivation, irregular sleep schedules,and high levels of stress—all of which Scott experienced—excessive caffeine intakecan trigger sleepwalking and other NREM parasomnias. At least one sleep expert believesthat Scott’s high caffeine use may have contributed to his outburst of sleep violence(Cartwright, 2007).For many people, a cup of coffee and a cigarette go hand in hand. Cigarettes containnicotine, another potent and addictive stimulant. Nicotine is found in all tobaccoproducts, including pipe tobacco,cigars, cigarettes, and smokeless tobacco.About 25 percent of Americanadults are cigarette smokers, and another5 percent use other tobacco products(SAMHSA, 2007). The proportionof smokers is much higher in Japan,many European countries, and developingcountries.Like coffee, nicotine increases mentalalertness and reduces fatigue or drowsiness.Brain-imaging studies show thatnicotine increases neural activity in many brain areas, including the frontal lobes,thalamus, hippocampus, and amygdala (Rose & others, 2003). Thus, it’s not surprisingthat smokers report that tobacco enhances mood, attention, arousal, andvigilance.When cigarette smoke is inhaled, nicotine reaches the brain in seconds. But overthe next hour or two, nicotine’s desired effects diminish. For the addicted person,smoking becomes a finely tuned and regulated behavior so that steady brainlevels of nicotine are maintained. At regular intervals ranging from about 30 to90 minutes, the smoker lights up, avoiding the withdrawal effects that are startingto occur. For the pack-a-day smoker, that averages out to some 70,000 “hits” ofnicotine every year.Nicotine is highly addictive, both physically and psychologically (Laviolette& van der Kooy, 2004). People who start smoking for nicotine’s stimulatingproperties often continue smoking to avoid the withdrawal symptoms. Along withan intense craving for cigarettes, withdrawal symptoms include jumpiness, irritability,tremors, headaches, drowsiness, “brain fog,” and light-headedness.nicotineA stimulant drug found in tobacco products.amphetamines(am-FET-uh-meens) A class of stimulantdrugs that arouse the central nervoussystem and suppress appetite.cocaineA stimulant drug derived from the coca tree.Amphetamines and CocaineLike caffeine and nicotine, amphetamines and cocaine are addictive substances thatstimulate brain activity, increasing mental alertness and reducing fatigue. However,amphetamines and cocaine also elevate mood and produce a sense of euphoria.When abused, both drugs can produce severe psychological and physical problems.Sometimes called “speed” or “uppers,” amphetamines suppress appetite and wereonce widely prescribed as diet pills. Tolerance to the appetite-suppressant effects occursquickly, so progressive increases in amphetamine dosage are required to maintain theeffect. Consequently, amphetamines are rarely prescribed today for weight control.