Introduction to Psychology

Saylor URL: http://www.saylor.org/books Saylor.org

Drug Description Street or brand names

Safety

ratio

Marijuana (Cannabis) Active ingredient is THC Pot, spliff, weed 1,000

Drugs with lower safety ratios have a greater risk of brain damage and death.

Source: Gable, R. (2004). Comparison of acute lethal toxicity of commonly abused psychoactive substances. Addiction, 99(6),
686–696.

Speeding Up the Brain With Stimulants: Caffeine, Nicotine, Cocaine, and

Amphetamines

A stimulant is a psychoactive drug that operates by blocking the reuptake of dopamine,
norepinephrine, and serotonin in the synapses of the CNS. Because more of these
neurotransmitters remain active in the brain, the result is an increase in the activity of the
sympathetic division of the autonomic nervous system (ANS). Effects of stimulants include
increased heart and breathing rates, pupil dilation, and increases in blood sugar accompanied by
decreases in appetite. For these reasons, stimulants are frequently used to help people stay awake
and to control weight.

Used in moderation, some stimulants may increase alertness, but used in an irresponsible fashion
they can quickly create dependency. A major problem is the “crash” that results when the drug
loses its effectiveness and the activity of the neurotransmitters returns to normal. The withdrawal
from stimulants can create profound depression and lead to an intense desire to repeat the high.

Caffeine is a bitter psychoactive drug found in the beans, leaves, and fruits of plants, where it
acts as a natural pesticide. It is found in a wide variety of products, including coffee, tea, soft
drinks, candy, and desserts. In North America, more than 80% of adults consume caffeine daily
(Lovett, 2005). [4]Caffeine acts as a mood enhancer and provides energy. Although the U.S. Food
and Drug Administration lists caffeine as a safe food substance, it has at least some
characteristics of dependence. People who reduce their caffeine intake often report being
irritable, restless, and drowsy, as well as experiencing strong headaches, and these withdrawal
symptoms may last up to a week. Most experts feel that using small amounts of caffeine during
pregnancy is safe, but larger amounts of caffeine can be harmful to the fetus (U.S. Food and
Drug Administration, 2007). [5]