Much is now known about the neural and molecular mechanisms that draw people to recreational
drugs. When you have a glass of beer, wine, or whiskey, the alcohol quickly affects your brain
chemistry. Because of increased concentrations of the neurotransmitter dopamine, there is increased
activity in the nucleus accumbens, a brain area associated with feelings of pleasure. Alcohol also
increases activity of the neurotransmitter GABA, which enables some neurons to inhibit the firing of
other neurons. You then get greater inhibition of neural firing, which in small doses of alcohol can
produce relaxation but in large doses can lead to lack of coordination, slurring of words, and even
passing out. Other neurotransmitters that are altered by alcohol include serotonin and norepinephrine.
Extensive studies with animals and humans support the following causal chain: drinking alcohol
changes your brain processes and thereby changes your thinking. Similarly, we know that people
become addicted to smoking cigarettes because nicotine stimulates acetylcholine receptors and
increases dopamine levels, producing a physical dependency.