Abuse Drugs—Use and Addiction - What Are Abuse And Addiction?

Scientists do not know why some people who use addictive substances become addicted and others do not. Results of numerous studies of identical and fraternal (nonidentical) twins, and families with histories of substance abuse and addiction, indicate that there is probably a genetic component to addiction. To date, however, researchers have not identified specific genes that would distinguish people who are at risk of becoming addicted. Results of a study published in 2004, however, show that a mutation in certain brain receptors lowers the threshold for nicotine dependence in mice with the mutation (Tapper et al., "Nicotine Activation of alpha4 Receptors: Sufficient for Reward, TABLE 1.2
Drug Enforcement Administration (DEA) drug schedules
SOURCE: Adapted from Drugs of Abuse, 2005 Edition, U.S. Department of Justice, Drug Enforcement Administration, 2005, http://www.usdoj.gov/dea/pubs/abuse/doa-p.pdf (accessed March 9, 2005)

Schedule I

The drug or other substance has a high potential for abuse. The drug or other substance has no currently accepted medical use in treatment in the United States. There is a lack of accepted safety for use of the drug or other substance under medical supervision. Examples of Schedule I substances include heroin, lysergic acid diethylamide (LSD), marijuana, and methaqualone.

Schedule II

The drug or other substance has a high potential for abuse. The drug or other substance has a currently accepted medical use in treatment in the United States or a currently accepted medical use with severe restrictions. Abuse of the drug or other substance may lead to severe psychological or physical dependence. Examples of Schedule II substances include morphine, phencyclidine (PCP), cocaine, methadone, and methamphetamine.

Schedule III

The drug or other substance has less potential for abuse than the drugs or other substances in Schedules I and II. The drug or other substance has a currently accepted medical use in treatment in the United States. Abuse of the drug or other substance may lead to moderate or low physical dependence or high psychological dependence. Anabolic steroids, codeine and hydrocodone with aspirin or Tylenol®, and some barbiturates are examples of Schedule III substances.

Schedule IV

The drug or other substance has a low potential for abuse relative to the drugs or other substances in Schedule III. The drug or other substance has a currently accepted medical use in treatment in the United States. Abuse of the drug or other substance may lead to limited physical dependence or psychological dependence relative to the drugs or other substances in Schedule III. Examples of drugs included in Schedule IV are Darvon®, Talwin®, Equanil®, Valium® and Xanax®.

Schedule V

The drug or other substance has a low potential for abuse relative to the drugs or other substances in Schedule IV. The drug or other substance has a currently accepted medical use in treatment in the United States. Abuse of the drug or other substances may lead to limited physical dependence or psychological dependence relative to the drugs or other substances in Schedule IV. Cough medicines with codeine are examples of Schedule V drugs.

Tolerance, and Sensitization," Science, vol. 306, November 5, 2004).

Research and treatment experts have identified three general levels of interaction with drugs: use, abuse, and dependence (or addiction). In general, abuse involves a compulsive use of a substance and impaired social or occupational functioning. Dependence (addiction) includes these traits, plus evidence of physical tolerance (a need to take increasingly higher doses to achieve the same effect) or withdrawal symptoms when use of the drug is stopped.

The progression from use to dependence is very complex, as are the abused substances themselves. Researchers have found no standard boundaries between using a substance, abusing a substance, and being addicted to a substance. They believe these lines vary widely from substance to substance and from individual to individual.

Physiological, Psychological, and Sociocultural Factors

Some researchers maintain that the principal causes of substance use are external social influences, such as peer pressure, while substance abuse and/or dependence result primarily from internal psychological and physiological needs and pressures, including inherited tendencies. Additionally, psychoactive drug use at an early age may be a risk factor (a characteristic that increases likelihood) for subsequent dependence.

Physically, mood-altering substances affect brain processes. Most drugs that are abused stimulate the reward or pleasure centers of the brain by causing the release of dopamine, which is a neurotransmitter—a chemical in the brain that relays messages from one nerve cell to another.

Psychologically, a person may become dependent on a substance because it relieves pain, offers escape from real or perceived problems, or makes the user feel more relaxed or confident in certain social settings. A successful first use of a substance may reduce the user's fear of the drug and thus lead to continued use and even dependence.

Socially, substance use may be widespread in some groups or environments. The desire to belong to a special group is a very strong human characteristic, and those who use one or more substances may become part of a subculture that encourages and promotes use. An individual may be influenced by one of these groups to start using a substance, or he or she may be drawn to such a group after starting use some-where else. In addition, a person—especially a young person—may not have access to alternative rewarding or pleasurable groups or activities that do not include substance use.

Figure 1.1 illustrates some relationships between physiological, psychological, and cultural factors that influence drinking and drinking patterns. Constraints (inhibitory factors) and motivations influence drinking patterns. In turn, drinking patterns influence the relationship between routine activities related to drinking and acute (immediate) consequences of drinking.

Definitions of Abuse and Dependence

Two texts provide the most commonly used medical definitions of substance abuse and dependence. The Diagnostic and Statistical Manual of Mental Disorders (DSM) is published by the American Psychiatric FIGURE 1.1
An ecological model of drinking behavior
SOURCE: "An Ecological Model of Drinking Behavior," in Alcohol Health & Research World, vol. 17, no. 1, 1993 (updated October 2000), http://www.niaaa.nih.gov/gallery/treatment/gruen.htm (accessed February 4, 2005) Association. The International Classification of Diseases (ICD) is published by the World Health Organization (WHO). While the definitions of dependence in the two manuals are almost identical, the definitions of abuse are not.

THE DSM DEFINITION OF ABUSE.

The text revision of the fourth edition of the DSM (DSM-IV-TR), published in 2000, defines abuse as an abnormal pattern of recurring use that leads to "significant impairment or distress," marked by one or more of the following in a twelve-month period:

• Failure to fulfill major obligations at home, school, or work (for example, repeated absences, poor performance, or neglect).
• Use in hazardous or potentially hazardous situations, such as driving a car or operating a machine while impaired.
• Legal problems, such as arrest for disorderly conduct while under the influence of the substance.
• Continued use in spite of social or interpersonal problems caused by the use of the substance, such as fights or family arguments.

THE ICD DEFINITION OF "HARMFUL USE."

The tenth (and most recent) revision of the ICD (ICD-10), endorsed by the Forty-third World Health Assembly in May 1990 and used in WHO Member States since 1994, uses the term "harmful use" rather than abuse. It defines harmful use as "a pattern of psychoactive substance use that is causing damage to health," either physical or mental.

Because the ICD manual is targeted toward international use, its definition must be broader than the DSM definition intended for use by Americans. Cultural customs of substance use vary widely, sometimes even within the same country.

DEFINITIONS OF DEPENDENCE.

In general, the DSM-
IV-TR and the ICD-10 manuals agree that dependence is present if three or more of the following occur in a twelve-month period:

• Increasing need for more of the substance to achieve the same effect (occurs as the user builds up a tolerance to the substance), or a reduction in effect when using the same amount as used previously.
• Withdrawal symptoms if use of the substance is stopped or reduced.

  FIGURE 1.2
  Drug use, abuse, and dependence
  SOURCE: "Figure 2-1. Drug Use, Abuse, and Dependence," in Technologies for Understanding and Preventing Substance Abuse and Addiction, U.S. Congress, Office of Technology Assessment, September 1994, http://www.wws.princeton.edu/cgi-bin/byteserv.prl/~ota/disk1/1994/9435/9435.PDF (accessed March 1, 2005)

• Progressive neglect of other pleasures and duties.
• A strong desire to take the substance or a persistent but unsuccessful desire to control or reduce the use of the substance.
• Continued use in spite of physical or mental health problems caused by the substance.
• Use of the substance in larger amounts or over longer periods of time than originally intended, or difficulties in controlling the amount of the substance used or when to stop taking it.
• Considerable time spent in obtaining the substance, using it, or recovering from its effects.

Progression from Use to Dependence

The rate at which individuals progress from drug use to drug abuse to drug dependence (or addiction) depends on many of the aforementioned factors. In general, each level is more dangerous, more invasive in the user's life, and more likely to cause social interventions, such as family pressure to enter treatment programs or prison sentences for drug offenses, than the previous level.

Figure 1.2 is a diagram of the progression to addiction. Notice that the intensification of use leads to abuse, and that abuse leads to addiction and dependence. The right side of the diagram shows social interventions appropriate at various stages of drug use, abuse, and dependence. The dotted lines to the left show that relapse after recovery may lead to renewed drug use, abuse, or dependence.