176 ChapTER 5 Body Rhythms and Mental States
person to person and from one time to another for
any individual. A “trip” may be mildly pleasant or
unpleasant, a mystical revelation or a nightmare.
For decades, research on psychedelics languished
because of a lack of funding, but a few clinical
researchers are now exploring their potential use-
fulness in psychotherapy, the relief of psychologi-
cal distress, the treatment of anxiety disorders, and
end-of-life distress (Griffiths et al., 2008). In a
pilot study in which moderate doses of psilocybin
were administered to 12 patients facing death
from advanced-stage cancer, the drug significantly
reduced anxiety and despair (Grob et al., 2011).Some commonly used drugs fall outside these
four classifications, combine elements of more
than one category, or have uncertain effects. One
is marijuana, which is smoked or, less commonly,
eaten in foods such as brownies; it is the most
widely used illicit drug in North America and
Europe. Some researchers classify it as a psyche-
delic, but others feel that its chemical makeup and
its psychological effects place it outside the major
classifications. The main active ingredient in mar-
ijuana is tetrahydrocannabinol (THC), derived
from the hemp plant, Cannabis sativa. In some
respects, THC appears to be a mild stimulant,
increasing heart rate and making tastes, sounds,
and colors seem more intense. But users oftenusually make a person feel calm or drowsy, and
they may reduce anxiety, guilt, tension, and inhibi-
tions. These drugs enhance the activity of GABA,
the neurotransmitter that inhibits the ability of
neurons to communicate with each other. In large
amounts, depressants may produce insensitivity to
pain and other sensations. Like stimulants, in very
large doses they can cause irregular heartbeats,
convulsions, and death.
People are often surprised to learn that al-
cohol is a central nervous system depressant. In
small amounts, alcohol has some of the effects of a
stimulant because it suppresses activity in parts of
the brain that normally inhibit impulsive behavior,
such as loud laughter and clowning around. In the
long run, however, it slows down nervous system
activity. Like barbiturates and opiates, alcohol
can produce anesthesia, which is why people may
pass out when they drink excessively (if they don’t
throw up first).
Over time, alcohol damages the liver, heart,
and brain. Extremely large amounts of alcohol can
kill by inhibiting the nerve cells in brain areas that
control breathing and heartbeat. Every so often,
a news report announces the death of a college
student who had large amounts of alcohol “fun-
neled” into him as part of an initiation or drink-
ing competition. On the other hand, moderate
drinking—a daily drink or two of wine, beer, or
liquor—is associated with a variety of health ben-
efits, including antidiabetic effects and a reduced
risk of heart attack and stroke (Brand-Miller et al.,
2007; Mukamal et al., 2003; Reynolds et al., 2003).3
Opiates relieve pain. They include opium,
derived from the opium poppy; morphine, a
derivative of opium; heroin, a derivative of mor-
phine; synthetic drugs such as methadone; and
codeine and codone-based pain relievers such as
oxycodone and hydrocodone. These drugs work on
some of the same brain systems as endorphins do,
and some have a powerful effect on the emotions.
When injected, opiates can enhance the transmis-
sion of dopamine and produce a rush, a sudden
feeling of euphoria. They may also decrease anxiety
and motivation. Opiates are highly addictive and in
large amounts can cause coma and even death.4
Psychedelic drugs disrupt normal thought pro-
cesses, such as the perception of time and
space. Sometimes they produce hallucinations,
especially visual ones. Some psychedelics, such
as lysergic acid diethylamide (LSD), are made in
the laboratory. Others, such as mescaline (from
the peyote cactus), Salvia divinorum (from an herb
native to Mexico), and psilocybin (from certain
species of mushrooms), are natural substances.
Emotional reactions to psychedelics vary fromMarijuana was once regarded as a mild and harmless
sedative, but its image changed in the 1930s, when
books and movies began to warn about the dire conse-
quences of the “weed with roots in hell.”