Saylor URL: http://www.saylor.org/books Saylor.org
[26] Hobson, J. A., & McCarley, R. (1977). The brain as a dream state generator: An activation-synthesis hypothesis of the dream
process. American Journal of Psychiatry, 134, 1335–1348; Hobson, J. A. (2004). Dreams Freud never had: A new mind
science. New York, NY: Pi Press.
5.2 Altering Consciousness With Psychoactive Drugs
LEARNING OBJECTIVES
- Summarize the major psychoactive drugs and their influences on consciousness and behavior.
- Review the evidence regarding the dangers of recreational drugs.
A psychoactive drug is a chemical that changes our states of consciousness, and particularly our
perceptions and moods. These drugs are commonly found in everyday foods and beverages,
including chocolate, coffee, and soft drinks, as well as in alcohol and in over-the-counter drugs,
such as aspirin, Tylenol, and cold and cough medication. Psychoactive drugs are also frequently
prescribed as sleeping pills, tranquilizers, and antianxiety medications, and they may be taken,
illegally, for recreational purposes. As you can see in Table 5.1 "Psychoactive Drugs by Class",
the four primary classes of psychoactive drugs are stimulants, depressants, opioids,
and hallucinogens.
Psychoactive drugs affect consciousness by influencing how neurotransmitters operate at the
synapses of the central nervous system (CNS). Some psychoactive drugs are agonists, which
mimic the operation of a neurotransmitter; some are antagonists, which block the action of a
neurotransmitter; and some work by blocking the reuptake of neurotransmitters at the synapse.
Table 5.1 Psychoactive Drugs by Class
Mechanism Symptoms Drug
Dangers and side
effects
Psychological
dependence
Physical
dependence
Addiction
potential
Addiction
potential
Stimulants
Stimulants block the
reuptake of dopamine,
norepinephrine, and
serotonin in the
synapses of the CNS.
Enhanced mood
and increased
energy
Caffeine
May create
dependence Low Low Low
Nicotine
Has major
negative health
effects if smoked High High High