Alcohol and the Developing Brain
Alcohol can cause alterations in the structure and function of the developing brain,
which continues to mature into a person’s mid 20s, and it may have consequences reaching
far beyond adolescence.
In adolescence, brain development is characterized by dramatic changes to the brain’s
structure, neuron connectivity (i.e., “wiring”), and physiology. These changes in
the brain affect everything from emerging sexuality to emotionality and judgment.
Not all parts of the adolescent brain mature at the same time, which may put an
adolescent at a disadvantage in certain situations. For example, the limbic areas
of the brain mature earlier than the frontal lobes. The limbic areas regulate emotions
and are associated with an adolescent’s lowered sensitivity to risk. The frontal
lobes are responsible for self-regulation, judgment, reasoning, problem-solving,
and impulse control. Differences in maturation among parts of the brain can result
in impulsive decisions or actions and a disregard for consequences.
How Alcohol Affects the Brain
Alcohol affects an adolescent’s brain development in many ways. The effects of underage
drinking on specific brain activities are explained below.
Alcohol is a central nervous system depressant.
Alcohol can appear to be a stimulant because, initially, it depresses the part of
the brain that controls inhibitions.
CEREBRAL CORTEX—Alcohol slows down the cerebral cortex as it works
with information from a person’s senses.
CENTRAL NERVOUS SYSTEM—When a person thinks of something he wants
his body to do, the central nervous system—the brain and the spinal cord—sends a
signal to that part of the body. Alcohol slows down the central nervous system,
making the person think, speak, and move slower.
FRONTAL LOBES—The brain’s frontal lobes are important for planning, forming ideas, making decisions, and using self-control.
When alcohol affects the frontal lobes of the brain, a person may find it hard to control her emotions and urges. She may act without thinking or even become violent.
Drinking alcohol over a long period of time can damage the frontal lobes forever.
HIPPOCAMPUS—The hippocampus is the part of the brain where memories
are made.
- When alcohol reaches the hippocampus, a person may have trouble remembering something
he just learned, such as a name or a phone number. This can happen after just one
or two drinks.
- Drinking a lot of alcohol quickly can cause a blackout—not being able to remember
entire events, such as what he did last night.
- If alcohol damages the hippocampus, a person may find it hard to learn and to hold
on to knowledge.
CEREBELLUM—The cerebellum is important for coordination, thinking,
and being aware. A person may have trouble with these skills when alcohol enters
the cerebellum. After drinking alcohol, her hands may be so shaky that she can’t
touch or grab things normally. She may lose her balance and fall.
HYPOTHALAMUS—The hypothalamus is a small part of the brain that
does an amazing number of the body’s housekeeping chores. Alcohol upsets the work
of the hypothalamus. After a person drinks alcohol, blood pressure, hunger, thirst,
and the urge to urinate increase while body temperature and heart rate decrease.
MEDULLA—The medulla controls the body’s automatic actions, such
as a person’s heartbeat. It also keeps the body at the right temperature. Alcohol
actually chills the body. Drinking a lot of alcohol outdoors in cold weather can
cause a person’s body temperature to fall below normal. This dangerous condition
is called hypothermia.
* We refer to a child as "him" in some places and "her" in others. We do this for easier reading. All information applies to both boys and girls unless otherwise specified.
Sources
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