You may not feel that using drugs is a problem. Maybe you feel that you are a casual user because you use drugs only now and then. You may feel that you can stop using drugs at any time.

But drug use quickly can become a habit, and for many people it may lead to abuse and addiction. You may begin to use drugs without thinking about how drugs can harm you and those you care about. Drug use may become part of your routine, like a morning cup of coffee.

How do you become addicted?

Your brain links pleasure with activities that help you live. For example, you need food to live, so your brain tells you that eating feels good. Food becomes something that you want every day.

Drugs target your brain's limbic system, which allows you to feel pleasure. This causes your brain to release a lot of dopamine and other chemicals that make you feel good. Since the pleasure only lasts a short time, you crave more drugs to get the good feeling back.

Over time, your brain adjusts to drugs by making less dopamine and other chemicals. With less of these chemicals, your brain can't function as well, and it becomes harder for you to feel pleasure. You take drugs to get the good feeling back.

Drugs also affect the parts of your brain that deal with judgment, decision-making, problem-solving, emotions, learning, and memory. They change how the cells in your brain send and process information.

These changes in your brain make it harder to think and make good choices. You may be less able to control your actions.

Drugs and your health

Drugs can cause you to have health problems. These problems include:

• Heart disease.
• Stroke.
• Depression.

Drugs also can lead to problems with thinking and remembering.

Different drugs harm your body in different ways.

• Inhalants and other drugs can damage cells in your brain and nervous system.
• Marijuana can cause learning and memory problems and harm your lungs.
• Cocaine can lead to heart, lung, and other problems.
• Ecstasy can lead to thought and memory problems. Using it a lot could lead to liver damage.
• Methamphetamine can affect blood vessels in the brain, causing a stroke. It can make you think people are out to get you (paranoia) and believe things that are not true (delusions).
• LSD can cause drug-induced psychosis. This means you may no longer know what is real or be able to think straight. You may have flashbacks in which you "relive" part of an LSD experience you had many years ago.
• Heroin taken with a needle (injections) can cause infections of the blood vessels and heart and liver or kidney disease. Sharing needles to use heroin can give you hepatitis B or C or HIV.