Daily use of heroin for a sufficient period of time at last introduces withdrawal sickness into the reinforcement picture. Physical dependence adds a potentially powerful source of negative reinforcement and introduces regularity to the addict's drive state by serving as a pacemaker for the lower bound frequency of use. Studies show that drugs that do not cause physical dependence (e.g., amphetamines) produce sporadic responding (Bejerot 1972, p. 12; Carey and Mandel 1968; Schuster and Thompson 1969, p. 489; Spealman 1979), whereas drugs that produce physical dependence (such as opiates) keep animals responding on a regular basis (Pickens et al. 1967). In early heroin use, the new pattern of avoiding withdrawal combines with the already existing recreational pattern of seeking the drug's positive effects. In the long-term addict, euphoria, withdrawal sickness, and other miscellaneous reinforcing effects combine in various proportions to yield a complex schedule of reinforcement that sustains continued use (McAuliffe and Gordon 1974). The exact weighting of each effect in the reinforcement schedule may vary from time to time within a given individual and from addict to addict. At the time of injection, street addicts who are sick from withdrawal and who have only maintenance doses on hand are obviously satisfied to respond to just one component of their schedule (McAuliffe and Gordon 1974). With a larger supply, they typically respond to both components by reducing sickness and enjoying euphoric effects, too. Oftentimes, having done so, they will take another dose soon afterward, to produce even more intense euphoria. Having already attended to withdrawal needs, this time the response is solely to the euphoric component. The weighting of these components across contemporary addicts ranges from one extreme, exemplified by rare addicts who almost never experience euphoria, to the other, exemplified by rare addicts we have interviewed who get high on virtually every injection. At any given time, most street addicts are distributed in intermediate positions, where they avoid withdrawal and receive intermittent positive rewards. Quite different combinations may be typical of medical-professional addicts, iatrogenic addicts, soldiers addicted in Vietnam (Gordon 1979), and so on. It is the history of reinforcement gained from using drugs in all of these ways that accounts for an individual's overall drug-derived motivation for opiate use.

COPING THEORY (p. 38)

Milkman/Frosch

The ready availability of a wide range of psychoactive agents provides the user with the freedom to select, with some degree of accuracy, a specifically altered ego state with known physical and psychological properties. Although initiation of use of a particular substance may be circumstantially determined, continued use or rapid cessation is related to the individual's unique psychophysical reaction to the drug. The motivation toward continued involvement is the integrated result of constitutional, social/environmental, and intrapsychic factors. Disturbances in the normally expected mastery of phase-specific conflicts in early childhood are hypothesized to result in defective ego functioning in the substance-prone individual. The overly stressed characteristic defense mechanisms of the defective ego are temporarily bolstered through pharmacologic support. If a particular drug-induced ego state

provides a mechanism for easing the discomfort of conflict, an individual may seek out that particular drug when that conflict is reexperienced. The reinforcing quality of temporary stress reduction leads to continued reliance and utilization. The drug of choice will be the pharmacologic agent which proves harmonious with the user's characteristic mode of reducing anxiety. Furthermore, the selected drug appears to produce an altered ego state which is reminiscent of and may recapture specific phases of early child development, e.g., heroin, first year; amphetamine, second to third year.

ADDICTIVE EXPERIENCES THEORY

Peele

(p. 142)

Persons use drugs, simply speaking, when they find such use to be rewarding in terms of values, needs, and overall life structure. Conceivably a drug can tulfill positive functions for an individual--such as enabling him or her to work better or to relate to others. Even in this case there is the danger that functioning in a positive sense will become dependent on continued drug use. In all cases, use of the drug will probably make it harder for the person to eliminate underlying and unresolved problems.

While the experience the drug produces for the person must provide rewards for him or her in order to maintain drug use, this is not to say that its objective impact on the user's life will not be negative. Thus narcotic or barbiturate users find the removal of pain and the absence of anxiety induced by the drug to be rewarding, even though these effects make them less sensitive to and less effective in dealing with their environment. In fact, it is this very depletion of capabilities which best guarantees continued use of the drug.

Consider the stimulant addict, such as the addicted coffee drinker, who uses caffeine to provide energy throughout the day. By masking fatigue, inadequate nutritional input, lack of exercise, etc., and all those deficiencies which force reliance on the caffeine, the drug makes the person less aware of the need to change his or her habits so as to be able to supply energy needs naturally. In this way, the caffeine perpetuates its own use.

SOCIAL NEUROBIOLOGICAL THEORY (p. 286)
Prescott

The continuation of substance usage is dependent, in part, upon the continuation of somatosensory affectional deprivation and the need to maintain friendships and social positions where those friendships and social positions are contingent upon the use of drugs or alcohol. Support for the continuing use of drugs is facilitated by the practices of modern medicine and the advertising practices of the pharmaceutical corporations. Social learning processes which operate at all levels of development (childhood to adulthood) capitalize upon the need for the body to find relief from tension and pain created in large part by

somatosensory affectional deprivation. Societal and moral values that are intrinsically opposed to somatosensory pleasure and sexual pleasure, in particular, provide support for the alternatives of drugs and alcohol. Societal opposition to massage parlors and prostitution but open acceptance and support of the alcohol industries is a case in point. Societal acceptance of addicting drugs that impair somatosensory pleasure, e.g., alcohol and methadone, and opposition to drugs that facilitate pleasure, e.g., marijuana and heroin, is another case in point. Carstairs' (1966) classic study should be consulted in this context as a dramatic illustration of the reciprocal inhibitory relationships between drug use and behaviors that are culturally determined. Carstairs reported on the use of bhang (marijuana) and alcohol in the two highest caste groups, Rajput and Brahmin, in a village in northern India. The Rajput, the warrior class, indulged in alcohol, which facilitated the expression of sexuality and violence. The Brahmin was the religious class and indulged in bhang, which facilitated religious experiences and enhanced their spiritual life. The holy men avoided alcohol, which they considered destructive to salvation, and would not permit a Hindu who had consumed alcohol to "enter one of his temples (not even a goddess temple) without first having a purgatory bath and change of clothes" (p. 105).

The continuation of use or abuse and the choice of drug are culturally influenced. A culture will support the use of certain drugs that are consistent with and supportive of its own mores and values and will oppose the use of those drugs that interfere with these mores and values. Thus, the U.S. culture, which is predominantly an extroverted, violent, and exploitive culture (sexually and economically), supports the use of alcohol, which facilitates these behaviors. Conversely, the U.S. culture opposes the "pleasure" drugs (marijuana and heroin), which inhibit violence and exploitation and facilitate introspective and contemplative behaviors. (This statement should not be construed as supporting drug use for recreational purposes.) The issue is not whether a drug is addicting or nonaddicting--alcohol is addicting (culturally supported) and marijuana is nonaddicting (culturally opposed); heroin is addicting (culturally opposed) and methadone is addicting (culturally supported). Both the fabric and the loom of culture must be understood if the choice of specific drugs and the continuation of use and abuse are to be understood.

GENETIC THEORY (p. 297)
Schuckit

Once someone does try a drug, the decision to continue using the substance probably involves a combination of social and biological factors. While genetically mediated reactions to the drug may play a larger role here than in the initiation of use, social factors still hold great influence.

Genetically influenced biological factors may be important in the balance of pleasant and unpleasant effects seen with almost all substances on their first try. Constitutional factors may determine the incidence and severity of adverse problems, such as coughing, nausea, or vomiting, and may mediate the intensity of pleasant effects as well. Thus, the individual's personality, usual level of anxiety, the mechanisms and

rate of metabolism of the substance, and the nervous system's sensitivity to the substance may all contribute to the final balance between the positive and negative effects of the first ingestion and in this way contribute to the individual's decision to try the substance again.

It also seems apparent from individual histories of smoking or opiate use, for example, that there are a variety of social and psychological factors which interact with the biological reactions. These would include peer pressures, the desire to assume an adult role and the need to copy parental models, and general societal values about the drug (e.g., alcohol and marijuana) which may influence an individual to try the drug on repeated occasions despite the early adverse consequences of taking the substance. With each repeated use, there may be a tendency for the more positive aspects of drug effects to predominate as "tolerance" develops to the negative consequences of the drug. This may make repeated use more and more likely.

AVAILABILITY AND PRONENESS THEORY

Smart

(p. 46)

Most users of illicit drugs do not continue their use to the point of addiction. A more common event is that the user tries the drug a few times, has his or her curiosity satisfied or finds the drug unrewarding and discontinues its use. Those who continue drug use to become daily or addicted users will display an unusually high level of proneness in terms of social or psychological needs. Proneness is likely to be a more important factor in continuing use than is availability. Since the first use has already taken place, the user has overcome the major difficulties in obtaining drugs. The user will know peers, siblings, or associates who are users and hence have some reasonable access to the drug. Those who experience especially great frustrations with ghetto life or who have major psychological problems will be more likely to continue use. As use continues, the user gains more access to drugs, and physical availability becomes less a problem than it is for new users or nonusers. However, for daily users of expensive drugs, a limit on their availability is set by economic costs. Users must increase their income by either legitimate or, more likely, nonlegitimate means in order to maintain their access to drugs at high levels of usage.

PERCEIVED EFFECTS THEORY (p. 50)

Smith

Any single act produces numerous and varied positive and negative consequences for the actor. Some will be recognized by the actor; some will not. Those that are recognized will be accorded differential importance. The aggregate of this mix of perceived consequences determines the likelihood that the act will be repeated. Substance use will continue as long as the aggregate benefits are perceived as being greater, or more valued, than the aggregate costs. The cost-benefit relationship depends on many variables, such as which substance is

used, its strength, the frequency of its use, the immediacy and intensity of its perceived effects, the needs the substance is perceived as satisfying and frustrating, the intensity of those needs, their importance and centrality in the user's life; and the effects use has on the user's concepts of Self and Ideal Self.

The match of the perceived drug-induced changes and the perceived needs of the user is important in determining whether or not use will continue. The individual who places high value on feeling strong, alert, decisive, and masterful is apt to find amphetamine or cocaine much more satisfying than a person who emphasizes peace, physical relaxation, and the contemplation of philosophical and metaphysical issues. A person of the latter type would probably find drugs like marijuana and LSD far more enjoyable. The better the match between the perceived substance effects and the user's needs, the more likely use is to continue.

The mood and cognitive changes caused by use of certain substances can temporarily alter the user's concepts of Self and Ideal Self. If use reduces the discrepancy between the user's perceptions of Self and Ideal Self, continuation of use is likely--even if those changes last only as long as the drug effect itself.

Whatever the substance, its use is likely to continue as long as the amount and pattern of use are perceived by the user as providing a net aggregate benefit, whether by physical or psychological gratification, reduction of physical or psychological distress, alteration of the user's perception of Self or Ideal Self, perceived enhancement of performance, or some other mechanism.

LIFE-THEME THEORY (p. 59)
Spotts/Shontz

After a period of experimentation with many substances (usually in the company of friends) the person who becomes a heavy, chronic user chooses the single drug or class of drugs which most nearly produces the ego state that is needed to patch over the problem on the ego/psyche axis. Another factor determining final choice is regular access to the desired substance. Some persons will settle on a drug that is second best, from a personal point of view (e.g., amphetamine), because they cannot obtain or afford the one they really want (cocaine). Once a drug that produces the desired ego state has been found, and once sources of supply have been established, social support for continuation of its use is no longer required. The person-drug relationship becomes self-sustaining.

FAMILY THEORY (p. 147)

Stanton

When drug use, especially heavy use, is continued for a prolonged period, it is helpful to view it as indicative that the user and the