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Alcohol and the brain

Published 12 December 2005.

Alcohol is one the substances that mainly affect the central nervous system (e.g. the brain and the spinal cord). It has a paralysing effect on the nervous system which then tries to neutralize the effect by increasing its irritability in order to be able to function.

The immediate effects of alcohol are a state of intoxication and passing out. Long-term, high-scale use of alcohol has many consequences:

Your mental capacity decreases. Changes will at first only occur when you are under the influence of alcohol, but later they may become permanent. Often also your ability to remember, take initiative and reason as well as your motor co-ordination will suffer. When you stop drinking, your abilities improve considerably. But if there have been great changes, you will not make a full recovery.

The possibility of convulsions increases. When the blood alcohol content has returned to zero after heavy drinking, there is an increased possibility of convulsions for some 48 hours. They are sudden fits of unconsciousness and spasms that may include biting the tongue or incontinence. Not everyone is predisposed to convulsions. Withdrawal convulsions do not require continuous epileptic medication. Strong withdrawal symptoms may, however, require temporary medication that prevents convulsions.

The functions of the cerebellum are damaged. It regulates motor co-ordination and balance. Alcohol causes the cell mass to decrease, and may finally result in a situation where it is difficult to maintain your balance in the dark, without the help of your sight. Walking up and down the stairs, in narrow corridors or in a crowd of people becomes difficult. Also co-ordinating the movements of your hands and even talking may sometimes become more difficult. Once this situation has developed, it cannot be cured.

The risk of a brain damage increases, especially for young people, as a strong intoxication lowers the blood sugar especially with the young. When the blood sugar becomes too low, the brain is deprived of energy. The result is brain damage.

So, what to do in order to avoid these consequences?

If you use alcohol, don’t drink so much that you pass out or have an accident. If your friend passes out, don’t leave him. With the appropriate treatment brain damage can be prevented. The best guarantee for the recovery and maintenance of your mental abilities is to stop drinking.

Antti Holopainen
medical superintendent,
Järvenpää Addiction Hospital

See the Drugs and the Brain animation here.