Drug abuse has a wide range of definitions, all of them relating either to the misuse or overuse of a psychoactive drug or performance enhancing drug for a non-therapeutic or non-medical effect, or referring to any use of illegal drug in the absence of a required, yet practically impossible to get, license from a government authority, in the USA this is the DEA. Some of the most commonly abused drugs include alcohol, amphetamines, barbiturates, caffeine, cannabis, cocaine, methaqualone, nicotine, opium alkaloids, and minor tranquilizers. Use of these drugs may lead to criminal penalty in addition to possible physical, social, and psychological harm, both strongly depending on local jurisdiction. Other definitions of drug abuse fall into four main categories: public health definitions, mass communication and vernacular usage, medical definitions, and political and criminal justice definitions
Public health definitions
In recent decades, public health practitioners have attempted to look at drug abuse from a broader perspective than the individual, emphasizing the role of society, culture and availability. Rather than accepting the loaded terms alcohol or drug "abuse," many public health professionals have adopted phrases such as "alcohol and drug problems" or "harmful/problematic use" of drugs.
Mass communication and vernacular usage
The term "drug abuse" may be used in newspapers, television, etc. in an ambiguous, catch-all sense rather than as a medical or legal term, sometimes disapprovingly to refer to any drug use at all, particularly of illicit drugs.
In the modern medical profession, the two most used diagnostic tools in the world, the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders (DSM) and the World Health Organization's International Statistical Classification of Diseases and Related Health Problems (ICD), no longer recognize 'drug abuse' as a current medical diagnosis. Instead, they have adopted substance abuse as a blanket term to include drug abuse and other things. However, other definitions differ; they may entail psychological or physical dependence, and may focus on treatment and prevention in terms of the social consequences of substance use.
Some of the most commonly abused drugs are alcohol, anabolic steroids, amphetamines, analgesics, barbiturates, benzodiazepines, caffeine, cannabis, cocaine, laxatives, methaqualone, opiates, and tobacco. Depending on the actual compound, drug abuse may lead to health problems, social problems, physical dependence, or psychological addiction.
Some drugs that are subject to abuse have central nervous system (CNS) effects, which produce changes in mood, levels of awareness or perceptions and sensations. Most of these drugs also alter systems other than the CNS. But, not all centrally acting drugs are subject to abuse, which suggests that altering consciousness is not sufficient for a drug to have abuse potential. Among drugs that are abused, some appear to be more likely to lead to uncontrolled use than others, suggesting a possible hierarchy of drug-induced effects relative to abuse potential.
Approaches to managing drug abuse
Attempts by government-sponsored drug control policy to interdict drug supply and eliminate drug abuse have been largely unsuccessful. In the United States, the number of nonviolent drug offenders in prison exceeds by 100,000 the total incarcerated population in the EU, despite the fact that the EU has 100 million more citizens. In spite of the huge efforts by the U.S., drug supply and purity has reached an all time high, with the vast majority of resources spent on interdiction and law enforcement instead of public health.
In addition to being a major public health problem, some consider drug abuse to be a social problem with far-reaching implications. Stress, poverty, domestic and societal violence, and various diseases (i.e., injecting drug users as a source for HIV/AIDS) are sometimes thought to be spread by drug use. Studies have also shown that individuals dependent on illicit drugs experience higher rates of comorbid psychiatric syndromes.
Beyond the sociological issues, many drugs of abuse can lead to addiction, chemical dependency, or adverse health effects, such as lung cancer or emphysema from cigarette smoking.
Medical treatment therefore centers on two aspects: 1) breaking the addiction, 2) treating the health problems.
Most countries have health facilities that specialize in the treatment of drug abuse, although access may be limited to larger population centers and the social taboos regarding drug use may make those who need the medical treatment reluctant to take advantage of it. For example, it is estimated that only fifteen percent of injection drug abusers thought to be in need are receiving treatment. Patients may require acute and long-term maintenance treatment and relapse prevention, complemented by suitable rehabilitation.
The development of pharmacotherapies for drug dependency treatment are currently in progress. New immunotherapies that prevent drugs like cocaine, methamphetamine, phencyclidine, nicotine, and opioids from reaching the brain are in the early stages of testing as is ibogaine, an alkaloid found in the Tabernanthe iboga plant of West Central Africa. Medications such as Buprenorphine, which block the drugs active site in the brain are another new option for the treatment of opioid addiction. Depot forms of medications, which require only weekly or monthly dosing, are also under investigation.
Traditionally, new pharmacotherapies are quickly adopted in primary care settings, however, drugs for substance abuse treatment have faced many barriers . Naltrexone, a drug marketed under the name "ReVia," is a medication approved for the treatment of alcohol dependence. Unfortunately, this drug has reached very few patients. This may be due to a number of factors, including resistance by addiction treatment providers and lack of resources.
Most countries have legislation designed to criminalize drug abuse. Usually however this is limited to drugs specified by the legislation. These drugs are often called illegal drugs but, generally, what is illegal is their unlicensed production, supply and possession. The drugs are also called controlled substances. Legal punishments, even for simple possession, can be quite severe (including the death penalty in some countries). Legal regimes vary across countries, and even within them, and have fluctuated widely throughout history.
Despite (and perhaps because of) the legislation many large, organized criminal drug cartels operate world-wide. Advocates of decriminalization argue that it is the legislation which makes drug dealing such a lucrative business, and leads to much of the associated criminal activity.