What is Addiction?: A Perspective

by Howard J. Shaffer, Ph.D., C.A.S.

From Division on Addictions

Acknowledgements: The author extends thanks to Chrissy Thurmond, Chris Reilly, Richard LaBrie, Debi LaPlante and Adrian Charles for their contributions to earlier versions of this article.

Addictive behaviors represent confusing and complex patterns of human activity (Shaffer, 1996, 1997). These behaviors include drug and alcohol abuse, some eating disorders, compulsive or pathological gambling, excessive sexual behaviors, and other intemperate behavior patterns. These behaviors have defied explanation throughout history. In this essay, I will attempt to clarify the nature of addiction and provide an introduction to the field of addictive behaviors.

The field of addictions rests upon a variety of disciplines. Medicine, psychology, psychiatry, chemistry, physiology, law, political science, sociology, biology and witchcraft have all influenced our understanding of addictive behavior. Most recently, biological explanations of addiction have become popular. These approaches seek to understand alcoholism, for example, by identifying the genetic and neurochemical causes of this problem. It is interesting to recognize that as we understand more about the biology of addiction, social and cultural influences become more—not less—important. To illustrate, not everyone who is predisposed genetically to alcoholism develops the disorder. Some people who are not prone bio-genetically to alcoholism or other addictions will acquire the condition. Therefore, social and psychological forces will remain very important in determining who does and who does not develop addictive behaviors.

Now it is common to think of drugs as "addictive." Warning labels inform us that tobacco is an addictive substance. We think of heroin and cocaine as addictive. Yet, addiction is not simply a property of drugs, though drugs are highly correlated with addiction. Addiction results from the relationship between a person and the object of their addiction. Drugs certainly have the capacity to produce physical dependence and an abstinence syndrome (e.g., neuroadaptation). New evidence suggests that neuroadaptation also results from addictive behaviors that do not require ingesting psychoactive substances (e.g., gambling).

Altlhough neuroadaptation (i.e., tolerance and withdrawal) can result from a variety of repetitive behaviors, neuroadaption is not the same as addiction. If neuroadaptation and its common manifestation of physical dependence were the same as addiction, then it would be incorrect to consider pathological gambling as an addictive behavior. It would be inaccurate to talk about sex and love addicts. Many people who use narcotics as post-operative pain medications never display addictive behavior even though they have became dependent physically on these psychoactive substances. Stopping drug abuse will not end addiction, since addictive behavior patterns (e.g., gambling) can exist in the absence of drug abuse. Addiction is not simply a qualitative shift in experience, it is a quantitative change in behavior patterns: things that once had priority become less important and less frequent behaviors become dominant. Addiction represents an intemperate relationship with an activity that has adverse biological, social, or psychological consequences for the person engaging in these behaviors.

Conceptual Confusion About the Definition of Addiction

Absent a clear definition of addiction, researchers will continue finding it very difficult to determine addiction prevalence rates, etiology, or the necessary and sufficient causes that stimulate recovery. Absent a working definition of addiction, clinicians will encounter diagnostic and treatment matching difficulties (e.g., Havens, 1982; Marlatt, 1988; Shaffer, 1987, 1992; Shaffer & Robbins, 1995). Satisfactory treatment outcome measures will remain elusive. Without a functional definition of addiction, social policy makers will find it difficult to establish regulatory legislation, determine treatment need, establish health care systems, and promulgate new guidelines for health care reimbursement.

Scientists and treatment providers are not the only ones with a problem when the meaning of addiction is fuzzy. The average citizen will find that, without a clear definition of addiction, the distinctions among an array of human characteristics (e.g., interest, dedication, attention to detail, craving, obsession, compulsion and addiction) will remain blurred. Finally, the contemporary conceptual chaos surrounding addiction must be resolved to clarify the similarities and differences—if these exist—between process or activity addictions (e.g., pathological gambling, excessive sexual behavior) and psychoactive substance using addictions (e.g., heroin or alcohol) (Shaffer, 1997).

Paradigms Serve Both Organizing and Blinding Functions

In response to my preceding comments, some clinicians, researchers and policy makers may argue that they indeed have an explicit definition of addiction. Since these individuals have a model, they incorrectly assume that they also have the truth; they assume that their model is accurate. In addition, they incorrectly assume that their model will work for the rest of us if only we could see the light (cf., Shaffer, 1994). However, this is the problem with worldviews in general and scientific paradigms (Kuhn, 1962) in particular: as a conceptual schema organizes one person’s thoughts, simultaneously, it blinds that person to alternative considerations (Shaffer & Gambino, 1983). Rigid thinking sets in and science fails to progress until anomalies challenge the conventional wisdom.

Distinctions Among Use, Abuse, Dependence, and Addiction

Absent a consensual definition of addiction, clinicians and social policy makers often are left to debate whether patients who use drugs also "abuse" drugs. Treatment programs regularly mistake drug users and "abusers" for those who are drug dependent. Too often the result is unnecessary hospitalization, increased medical costs, and patients who learn to distrust health care providers; alternatively, absent a precise definition of addiction, some patients fail to receive the care they require. As a result of these complex conditions, practice guidelines in the addictions are equivocal and health care systems experience management and reimbursement chaos. [Although a full discussion of this matter is beyond the scope of this essay, it also is important to note that not all people with addiction are impaired in every aspect of their daily life. Despite some exceptions, substance addictions tend to be more broad-spectrum disorders while pathological gambling tends to be a more narrow-spectrum disorder.]

Even under most established constructions of addiction, not all drug dependent patients evidence addictive behavior. For example, in most civilized countries, under nearly all traditional circumstances, people who are nicotine dependent do not evidence addiction with its attendant anti-social behavior pattern. When tobacco is recast as a socially or legally illicit substance, however, these antisocial aspects of addictive behavior have emerged (e.g., Reuters News Service, 1992).

Complicating matters, neuroadaptation and physical dependence can emerge even in the absence of psychoactive drug use. For example, upon stopping, pathological gamblers who do not use alcohol or other psychoactive drugs often reveal physical symptoms that appear to be very similar to either narcotics, stimulants, or poly-substance withdrawal (e.g., Shaffer, Hall, Walsh, & Vander Bilt; 1995; Wray & Dickerson, 1981). Perhaps repetitive and excessive patterns of emotionally stirring experiences are more important in determining whether addiction emerges than does the object of these acts.

Addiction with Dependence and Without Dependence: Substances and Process

If addiction can exist with or without physical dependence, then the concept of addiction must be sufficiently broad to include human predicaments that are related to both substances and activities (i.e., process addictions). Although it is possible to debate whether we should include substance or process addictions within the kingdom of addiction, technically there is little choice. Just as the use of exogenous substances precipitate impostor molecules vying for receptor sites within the brain, human activities stimulate naturally occurring neurotransmitters (e.g., Hyman, 1994; Hyman & Nestler, 1993; Milkman & Sunderwirth, 1987). The activity of these naturally occurring psychoactive substances likely will be determined as important mediators of many process addictions.

The Neurochemistry of Addiction: Shifting Subjective States

We may be able to advance the field by considering the objects of addiction to be those things that reliably and robustly shift subjective experience. The most reliable, fast-acting and robust "shifters" hold the greatest potential to stimulate the development of addictive disorders. In addition, the strength and consistency of these activities to shift subjective states vary across individuals. Currently, we cannot predict with precision who will become addicted. Nevertheless, psychoactive drugs and certain other activities like gambling, exercising, and meditating will correlate highly with shifting subjective states because these activities reliably influence experience—and therefore neurochemistry. Consequently, psychoactive drug use and other activities (e.g., gambling) that can potently and reliably influence subjective state shifts will tend to be ranked high among the full range of activities that can associate with addictive behaviors.

Objects of Addiction: Cause, Consequence, or Relationship

To this point, I have implied tacitly that simply using drugs or engaging in certain activities do not cause addiction. Now let me be explicit: from a logical perspective, the objects of addiction are not the sole cause of addictive behavior patterns. The teleological aspects of addiction theory and practice contribute much to contemporary conceptual chaos. If drug using were the necessary and sufficient cause of addiction, then addiction would occur every time drug using was present. Similarly, if drug using was the only cause of addiction, addictive behaviors would be absent every time drug using was missing. However, as I described before, neuroadaptation and pathological gambling are often present when drug using is absent. Therefore, either drug using is not a necessary and sufficient cause to produce addiction or gambling disorders are not representative of addictive behaviors. Furthermore, using psychoactive drugs may not be a primary cause of addiction. Even though drug using is highly correlated with addiction—because psychoactive substances reliably shift subjective experiences—drug taking is neither a necessary nor a sufficient cause of addiction. Pathological gambling and excessive sexual behaviors that do not fall within the domain of obsessive compulsive disorders reveal that addiction can exist without drug taking. These observations serve to remind us that the objects of addiction do not fully explain the emergence of addiction. Consequently, scientists need to develop a model of addiction that can better account for a more complex relationship between a person who might develop addiction and the object of their dependence. One strategy for developing a new model is to emphasize the relationship instead of either the attributes of the person struggling with addiction or the object of their addiction.

To emphasize the relationship between the addicted person and the object of their excessive behavior serves to remind us that it is the confluence of psychological, social and biological forces that determines addiction. No single set of factors adequately represents the multi-factorial causes of addiction (e.g., Shaffer, 1987, 1992; Zinberg, 1984). Unfortunately, the parameters of this unique relationship also are difficult to define. Therefore, until experience provides more insight into the synergistic nature of these factors and helps us determine the interactive threshold(s) that may apply, we are forced to operationalize addiction so that researchers, clinicians and policy makers can share a common perspective (Shaffer, 1992; Shaffer & Robbins, 1991; 1995).

Using an Operational Definition: A Simple Behavioral Model:

In the field of addictions, workers need precise operational definitions. To avoid confusion, researchers and clinicians have developed handy operational schemes to reduce inconsistency. One simple model for understanding addiction is to apply the three Cs:

• Behavior that is motivated by emotions ranging along the Craving to Compulsion spectrum

• C ontinued use in spite of adverse consequences and

• Loss of Control.

Vague definitions of addiction, encouraged Vaillant (1982) to note that recognizing alcoholism (and perhaps other addictions) ultimately was similar to identifying a mountain or season; when confronted with these situations, we know these things implicitly. However useful, tacit knowledge is insufficient architecture upon which to rest the advancement of a science.

As a young science, the addictions represents a growing body of knowledge and a variety of emerging biological and social science methodologies—with all of the attendant rules and regulations of science—for expanding and verifying the emerging knowledge base. If the field of addictions is to mature, as have other domains of science, we must diligently work toward conceptual clarity. To develop theoretical precision, the field of addictions must escape from the cloak of partisan ideas. Conceptual clarity does not require that clinicians, researchers and social policy makers agree. However, it does require that as addiction specialists we define our concepts and work precisely and operationally. Under these conditions, treatments and research become replicable. The full tapestry of addiction patterns begins to emerge. The freedom to explore important issues develops. Conceptual chaos diminishes and, with all of its inherent debates, science progresses (e.g., Shaffer, 1986).