Drugs have a severe impact on the brain and body of the user. Even mild substances like alcohol can have major effects on a human body over time. The aging process can be speed up by the use of drugs, which can bring with it increased chances of life threatening diseases such as cancer. Now you might think that this isn't so bad, that it would be easy to give up drugs, that one little try won't hurt. Anyone who thinks that is, sadly wrong. Addiction is a powerful force. You see the brain has a natural reward system, when you eat or drink you experience a relative high, and are compelled to do so again. This is caused by neurotransmitters which are natural parts of the brain. Drugs stimulate these neurotransmitters into producing an unnatural high. This process induces addiction. Once you've had a taste of the extreme highs cause by drugs such as Cocaine or Marijuana, it is difficult to go back to the natural highs induced by everyday life. Many of these drugs not only cause a dependency, they also have other negative effects on the body such as decreases in brain activity, and dulling of reflexes. All in all it is best to stay away from drugs, alcohol, and cigarettes. Weather they're legal or illegal, they all have negative effects on the body and mind of the people who use them.