From a professional point of view, with the exception of food, no change of our physical and psychological function are drug substances. Many people mistakenly believe that "drugs" runescape accounts the term refers only to certain drugs or drug use of prohibited chemicals. They are not aware of, such as alcohol, tobacco of those we are familiar with the material is also a drug. This is also the number of physicians and psychologists are now using the "substance" of the more neutral term reasons. They used "substance abuse" instead of "drug abuse" to make it clear that abuse of alcohol, tobacco abuse of such substances as harmful as heroin and cocaine.

We live in a substance (drug) in the medical and social aspects of the use of a wide range of society are: aspirin to ease the headache for the business of wine, morning coffee to refreshing,runescape money but also used cigarettes. The use of these substances has been recognized by society, and clearly have a positive effect, but when it becomes an abuse? First of all, most of the excessive use of substances will have a negative impact, such as poisoning or serious disorder of perception. Repeated use of a substance that can lead to addiction or substance dependence. Performance is dependent on the initial resistance of the growing volume, it is necessary to produce the desired effect of the drug dose needs increasing, and will appear once the interruption of the use of uncomfortable symptoms of drug withdrawal.

The impact of the central nervous system, changes in perception and behavior of the drug (substance) is to play a significant role in neural material, they are usually divided into stimulants, depressants and hallucinogens. The main stimulants to speed up or play the role of the central nervous system activation, and tranquilizers were the opposite: slow down its activities. Hallucinogens major impact on people's perception, through a variety of ways to distort or change the perception, including hallucinations. These substances are often believed to be able to "cause hallucinations" (psychedelic word derived from Greek, meaning "soul show"), because they seem to change the state of human consciousness.