Substance Abuse and Dependence Health Article

Definition

Substance abuse and dependence refer to any continued pathological use of a medication, non-medically indicated drug (called drugs of abuse), or toxin. Although there are on-going debates on the exact distinctions between substance abuse and substance dependence, the current practice standard—distinguishes between the two by defining substance dependence in terms of physiological and behavioral symptoms of substance use, and substance abuse in terms of the social consequences of substance use.

Substance abuse is any pattern of substance use that results in repeated adverse social consequences related to drug-taking—for example, failure to meet work, family, or school obligations, interpersonal conflicts, or legal problems. Substance dependence, commonly known as addiction, is characterized by physiological and behavioral symptoms related to substance use. These symptoms include the need for increasing amounts of the substance to maintain desired effects, withdrawal if drugtaking ceases, and an inordinate amount of time spent in activities related to substance use.

Substance abuse is more likely to be diagnosed among those who have just begun drug-taking and is often an early symptom of substance dependence. However, substance dependence can appear without substance abuse, and substance abuse can persist for extended periods of time without a transition to substance dependence.

Description

Substance abuse and dependence are disorders that affect all population groups although specific patterns of abuse and dependence vary with age, gender, culture, and socioeconomic status. According to data from the National Longitudinal Alcohol Epidemiologic Survey, 13.3% of the nationally representative survey group exhibited symptoms of alcohol dependence during their lifetime, and 4.4% exhibited symptoms of alcohol dependence during the past 12 months. According to the 1997 National Household Survey on Drug Abuse, 6.4% of those surveyed had used an illicit drug in the past month.

Although substance dependence can begin at any age, persons aged 18 to 24 have relatively high substance use rates, and that dependence often arises sometime during the ages of 20 to 49. Gender proportions vary according to the class of drugs, but substance use disorders are in general more frequently seen in men.

In addition to being an individual health disorder, substance abuse and dependence may be viewed as a public health problem with far-ranging health, economic, and adverse social implications. Substance-related disorders are associated with teen pregnancy and the transmission of sexually transmitted diseases (STDs), as well as failure in school, unemployment, domestic violence, homelessness, and crimes such as rape and sexual assault, aggravated assault, robbery, burglary, and larceny. According to the National Institute on Alcohol Abuse and Alcoholism (NIAAA), the estimated cost of alcohol-related disorders alone (including health care expenditures, lost productivity, and premature death) was $166.5 billion in 1995.

The term substance, when discussed in the context of substance abuse and dependence, refers to medications, drugs of abuse, and toxins. These substances have an intoxicating effect, desired by the user, which can have either stimulating (speeding up) or depressive/sedating (slowing down) effects on the body. Substance dependence and/or abuse can involve any of the following 10 classes of substances:

• alcohol
• amphetamines (including "crystal meth, " some medications used in the treatment of attention deficit disorder [ADD], and amphetamine-like substances found in appetite suppressants)
• cannibis (including marijuana and hashish)

• cocaine (including "crack")
• hallucinogens (including LSD, mescaline, and MDMA ["ecstasy"])
• inhalants (including compounds found in gasoline, glue, and paint thinners)
• nicotine (substance dependence only)
• opioids (including morphine, heroin, codeine, methadone, oxycodone [Oxycontin (TM)])
• phencyclidine (including PCP, angel dust, ketamine)
• sedative, hypnotic, and anxiolytic (antianxiety) substances (including benzodiazepines such as valium, barbiturates, prescription sleeping medications, and most prescription anti-anxiety medications)

Caffeine has been identified as a substance in this context, but as yet there is insufficient evidence to establish whether caffeine-related symptoms constitute substance abuse and dependence.

Substances of abuse may thus be illicit drugs, readily available substances such as alcohol or glue, over-thecounter drugs, or prescription medications. In many cases, a prescription medication that becomes a substance of abuse may have been a legal, medically indicated prescription for the user, but the pattern of use diverges from the use prescribed by the physician.