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Drug abuse and addiction

What is drug addiction?

Drug addiction causes a person to be dependent on an illegal drug or a medication.

They may not be able to stop abusing the drug without help, and may have relapses despite the harm the substance is causing.

Drug addiction is a brain disease because the use of drugs leads to changes in the structure and function of the brain. Although it is true that for most people the initial decision to take drugs is voluntary, over time the changes in the brain caused by repeated drug use can affect a person's self-control and ability to make sound decisions, and at the same time send intense impulses to take drugs.

It is because of these changes in the brain that it is so challenging for a person who is addicted to stop using drugs. Fortunately there are treatments that help people to counteract an addiction's powerful disruptive effects and regain control. Research shows that combining addiction treatment medication, if available, with behavioural therapy offers the best chance of achieving success for most patients. Treatment approaches that are tailored to each patient's drug use patterns and any co-occurring medical, psychiatric and social problems can lead to sustained recovery and a life without drug abuse.

Drug addiction can be managed successfully. Plus, as with other chronic diseases, it is not uncommon for a person to relapse and begin using drugs again. However, relapse does not indicate failure - instead it indicates that treatment should be reinstated, adjusted or that alternate treatment is needed to help the individual regain control and recover.

What happens to your brain when you take drugs?

Drugs are chemicals that tap into the brain's communication system and disrupt the way nerve cells normally send, receive and process information. There are at least two ways that drugs are able to do this by imitating the brain's natural chemical messengers, and/or by over stimulating the "reward circuit" of the brain.

Some drugs - such as marijuana and heroin - have a similar structure to chemical messengers, called neurotransmitters, which are naturally produced by the brain. Because of this similarity, these drugs are able to "fool" the brain's receptors and activate nerve cells to send abnormal messages.

Other drugs - such as cocaine or methamphetamine - can cause the nerve cells to release abnormally large amounts of natural neurotransmitters, or prevent the normal recycling of these brain chemicals, which is needed to shut off the signal between neurons. This disruption produces a greatly amplified message that ultimately disrupts normal communication patterns.

Nearly all drugs, directly or indirectly, target the brain's reward system by flooding the circuit with dopamine. Dopamine is a neurotransmitter present in regions of the brain that control movement, emotion, motivation and feelings of pleasure. The overstimulation of this system, which normally responds to natural behaviours that are linked to survival (eating, spending time with loved ones, etc), produces euphoric effects in response to the drugs. This reaction sets in motion a pattern that "teaches" people to repeat the behaviour of abusing drugs.

WebMD Medical Reference

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