Substance addiction

Everyday on his way to school, Michael walks past a town centre. There, the alcoholics and drug addicts gather. Michael thinks their life seems like a nightmare. He wonders. Why do people take drugs, when it so clearly hurts them?

A person that takes an illegal drug or abuses pharmaceutical drugs, for a long time, often develops an addiction. To be addicted means that one yearns intensively for the drug, and spends a large share of one's time thinking about or trying to get hold of the drug. If the addiction is strong, one might do anything to get hold of the drug, even though one knows that it hurts one's life and health. With time, giving such high priority to a drug often leads to conflicts, losing friends, work and family, and ruining one's finances. So, there's hardly anyone who wants to get caught in drug addiction.

But still, a lot of people do. Because drugs can give a pleasant experience, of relief and enjoyment. At least in the beginning. And that has to do with the body's reward system. It's in the reward system that pleasure sensations arise - when we do things we enjoy - and that are good for us: Like eating, sleeping, exercising, spending time with friends, or having sex.

When we do things that are good for us, the reward system is stimulated, and the body sends out neurotransmitters and hormones, that makes us happy, alert, or relaxed. One example of such a substance is an endorphin. That's a hormone that relieves pain and makes us feel relaxed and happy. When we exercise or fall in love, the body releases especially large doses of endorphins. The trouble with the reward system is that it's pretty easy to fool.

And that's what happens when a person takes drugs. This is how it works: The drug heroin contains a substance that is similar to the body's own endorphins. It kidnaps the brain's reward system, and gives a strong feeling of pleasure. Normally, the brain controls the amount of endorphins it produces -- it regulates the level -- to keep it stable. That's why the blissful rush of pleasure you get when you have fallen in love doesn't last very long.

The body's regulation of the amount of endorphins is important to keep our moods from swinging up and down. But if a person takes drugs, this balance is thrown, and the body stops producing its own endorphins. When the drugs leave the body later ... and that happens pretty quickly... the body doesn't have any endorphins of its own to rely on.

Then the person feels really bad! To avoid feeling so bad, it might be tempting to take more drugs. It might help for a short while, but it also makes the body's own ability to keep the endorphin levels stable, even worse. And this time the drug doesn't give that same sense of pleasure anymore. Instead, the body needs more and more of the drug, to get the same effect.

The body has got used to the drug... the tolerance has increased. And if one tries to quit using the drug, one often feels very, very bad. Feeling bad from not taking a drug, is called having withdrawal symptoms. This can take the form of nausea, headache, shivers, feeling cold, nervous, worried and anxious, or even panic.

Which withdrawal symptoms appear depends among other things on which drug it is, that the brain and body has become accustomed to. So, drug addiction, is not a simple thing. It has many parts: The drug gives a temporary relief from unpleasant feelings. The yearning for the drug takes up much time and dominates one's life Conflicts with friends, family and work The body's tolerance increases Removal of the drug causes withdrawal symptoms.