Effects of Drugs of Abuse on the Brain

Pleasure, which scientists call reward, is a very powerful biological force for our survival. If you do something pleasurable, the brain is wired in such a way that you tend to do it again. Life sustaining activities, such as eating, activate a circuit of specialized nerve cells devoted to producing and regulating pleasure. One important set of these nerve cells, which uses a chemical neurotransmitter called dopamine, sits at the very top of the brainstem in the ventral tegmental area (VTA) (Figure 6). These dopamine-containing neurons relay messages about pleasure through their nerve fibers to nerve cells in a limbic system structure called the nucleus accumbens. Still other fibers reach to a related part of the frontal region of the cerebral cortex. So, the pleasure circuit, which is known as the mesolimbic dopamine system, spans the survival- oriented brainstem, the emotional limbic system, and the frontal cerebral cortex.

DefinitiOn Of DrUg and DrUg AbUse

Definition Of Drug

According to Ray(1983) in Drug abuse's (Prevention and rehabilitations in Malaysia), a drug will be defined as any substance other than food which by its chemical or physical nature alters the structure or functions in the living organism. Besides that, it is necessary to differentiate between psychoactive agents or those drugs that influence how the mind works and narcotics, which are often used to describe opium and its derivate.

According to David Duncan and Robert Gold in Drug and The Whole Person(1982), drug is substances that is chemically approved for the treatment of disease or relieve from pain are readily labeled drugs, as are substances obtained from a black market for recreational use.


Definition Of Drug Abuse

Drug abuse implies the misuse of certain substances- it is a moral, not scientific term. "An unstandardized, valve-laden and highly relative term used with a great deal of imprecision and confusion, generally implying drug use that is excessive, dangerous, or undesirable to the individual or community and that ought to be modified" (Nelson et al.1983.33)

Such definition of drug abuse typically refer to:
1. The non medical use of a substance
2. To alter the mental state
3. In a manner that is detrimental to th individual or the community, and/or
4. That is illegal

The other definition about drug abuse is a drug that is taken for non medicinal reasons (usually for mind-altering effects) : drug abuse can lead to physical and mental damage and with some substances depended and addiction.

Source : Drug Abuse (Prevention and Rehabilitation in Malaysia)
Drugs an Introduction
www.wordwidewebonline.com/en/DRUGABUSE