Drug use can cause you to lose your ability to remember things, to think clearly and to study properly. Drug use gives you the impression that you are more alert and aware, but under the influence of drugs you are actually less aware, and less alert.
Drug use can also cause people to act in strange unpredictable ways. A person can undergo a complete personality change when under the influence of drugs. Since drug residues can remain in the body for many years after they were taken, the effect on the mind can last a long time. Don't lose your mind! Avoid drugs.