Understanding Psychology (10th Ed)

160 Chapter 
5 
States of Consciousness
high affords from the everyday pressures of life, to an attempt to achieve a religious 
or spiritual state. However, other factors having little to do with the nature of the 
experience itself, also lead people to try drugs (McDowell & Spitz, 1999). 
For instance, the highly publicized drug use of role models such as movie stars 
and professional athletes, the easy availability of some illegal drugs, and peer pres-
sure all play a role in the decision to use drugs. In some cases, the motive is simply 
the thrill of trying something new. Finally, genetic factors may predispose some 
people to be more susceptible to drugs and to become addicted to them. Regardless 
of the forces that lead a person to begin using drugs, drug addiction is among the 
FIGURE 1 
How many teenagers use 
drugs? The results of the most recent 
comprehensive survey of 14,000 high 
school seniors across the United States 
show the percentage of respondents 
who have used various substances for 
nonmedical purposes at least once. Can 
you think of any reasons why teenagers—
as opposed to older people—might be 
particularly likely to use drugs? 
(Source: 
Johnston et al., 2009.)
5
0
10
15
20
25
30
40
45
35
50
Percent
Amphetamines
Alcohol
Cigarettes
Marijuana
Tranquilizers
Hallucinogens
Cocaine
Ecstacy
Steroids
FIGURE 2 
Diff erent drugs aff ect 
diff erent parts of the nervous system 
and brain and each drug functions in 
one of these specifi c ways.
Enhances release of 
neurotransmitter 
Enhances by mimicking 
neurotransmitter 
Blocks removal of 
neurotransmitter 
Blocks release of 
neurotransmitter 
Blocks receptor for
neurotransmitter
StudyAlert
Use Figure 2 to learn the dif-
ferent ways that drugs pro-
duce their eff ects on a 
neurological level.
feL82795_ch05_138-171.indd Page 160 7/22/10 5:52 PM user-f465
feL82795_ch05_138-171.indd Page 160 7/22/10 5:52 PM user-f465
/Users/user-f465/Desktop
/Users/user-f465/Desktop

---