Substance abuse otherwise known to many as drug abuse is the recurrent us of a substance referred to as a drug whereby the user consumes the substance in quantities or methods neither approved nor advised by the required professionals i.e doctors and this definition also applies when certain activities are performed using the substances contrary to the policies and rules that govern their (drugs) originally intended use.
In addition to there being many drugs already on the global market ,the commonly abused drugs may most at times veer off the commonly expected abused drugs and may not be easily identified as may be seen in the following short listing of common classes and types of drugs there being Narcotics ,Hallucinogens ,Depressants ,Stimulants ,Illicit drugs ,Cannabis ,Paints and Glues bringing into focus the clear fact that mood-altering and psychoactive substances are not the only types of drugs abused.
To further understand the issue of substance abuse, an in-depth knowledge of the various characteristics of a few of the drug classes listed above would be important as is clearly seen below.
Narcotics to begin with are derived from the word narcotic which is believed to have been coined by Galen, an ancient physician of Greek origin while referring to plant based agents that numb the body causing paralysis or loss of feeling and greatly based on narcosis, a term greatly used by Hippocrates to refer to the process of numbing. Narcotics are originally referred medically to as any compounds of psychoactive nature that possess sleep inducing properties.
Depressants otherwise known as sedatives on the other hand can be defined as endogenous compounds that work to lower or inhibit the functions of the human central nervous system thus reducing the bodies ultimate excitability levels. This sedatives though widely used prescriptively throughout the world has many effects majorly being
References: 1. http://www.webmd.com/mental-health/drug-abuse-addiction?page=2 2. www.who.int/topics/substance_abuse 3. http://www.drugabuse.gov/drugs-abuse 4. http://teens.drugabuse.gov/drug-facts/stimulants 5. http://archives.drugabuse.gov/stressanddrugabuse.html