404 CHAPTER 9
Depressants
Ringo Starr and John Lennon both had long periods of alcohol dependence. Starr
reported that he “wasted” some years on alcohol, initially feeling that drink-
ing gave him confi dence but realizing later that it really didn’t (Graff, 1989).
And Lennon was frequently drunk during his 18-month separation from his wife,
Yoko Ono.What Are Depressants?
Alcohol is a depressant. Other depressants are opiates, barbiturates, and benzodi-
azepines such as diazepam (Valium). In contrast to stimulants, depressants tend to
slow a person down, decreasing behavioral activity and level of awareness. Regular
use of depressants tends to lead to tolerance, and discontinuing their use or cutting
back on the dosage or frequency can produce withdrawal symptoms. In this section,
we will discuss the effects of use, abuse of, and dependence on three types of depres-
sants: alcohol, barbiturates, and benzodiazepines.Alcohol
Approximately 50% of people in the United States aged 12 and older report that they
have had at least one alcoholic beverage within the previous month (SAMHSA, 2008).
But using a substance isn’t the same as abusing it. Approximately 6% of Americans
aged 12 or older (15 million people) are considered either to abuse or to be dependent
on alcohol. Those who start to drink alcohol earlier in life are more likely to develop
a disorder related to drinking (SAMHSA, 2008). But alcohol abuse and dependence
aren’t equally prevalent among all racial and ethnic groups: Native Americans have
the highest prevalence of alcohol abuse and dependence (NIDA, 2003), and Blacks
are 40% less likely than Whites to develop alcohol abuse (Grant et al., 2008).Blood Alcohol Concentration
The quantity of alcohol isn’t the only variable that determines intoxication.
In fact, the crucial variable is blood alcohol concentration, which is affected
by the number of drinks consumed, the period of time over which they were
consumed, the time since the individual has last eaten, the individual’s body
weight, and the individual’s gender. Different concentrations of alcohol in the
blood are associated with different neurological and psychological states (see
Figure 9.8). In the United States, Canada, and Mexico, 0.08% is the legal
limit of blood alcohol concentration for driving.
It can be harder than you might think to regulate just how much alco-
hol you drink. For example, pouring drinks into short, wide glasses may
lead people to imbibe a larger dose of alcohol than intended. A study found
that college students, as well as professional bartenders, were likely to pour
20% more alcohol into a shorter, wider glass than into a taller, narrower
one. Even with practice, participants poured more into the wider glasses
than the narrower ones (Wansink & Ittersum, 2005).
The same amount of alcohol will have a slightly greater effect on a woman than
a man of the same size and weight, because men and women metabolize the drug
differently (Frezza et al., 1990). This sex difference arises in part because women
have, on average, less total water content in their bodies than do men, which means
that ingested alcohol is less diluted (Greenfi eld, 2002; Van Thiel et al., 1988).
Not only do the effects of a given amount of alcohol differ by gender, but there
are also individual differences. Some people have a more intense response to alcohol
than do others. This variability appears to be mediated in part by genes (Schuckit,
1999), but it is also related to the level of tolerance an individual has acquired.Binge Drinking
Binge drinking,orheavy episodic drinking, occurs when a person drinks until his or
her blood alcohol concentration reaches at least 0.08% in a 2-hour period (whichDespite practice pouring the same quantity of
liquid regardless of the shape of the glass, par-
ticipants in one study poured more into shorter
glasses than into taller ones (Wansink & Ittersum,
2005). Even professional bartenders are prone
to estimate the quantities in differently shaped
glasses incorrectly.Daniel Templeton/Alamy