Ideally, we would like to find effective “cures” for addictions, as we have for some cancers.

With a cure, the addict’s disordered motivational system would be “restored to health” and the addictive behavior would no longer have a dominant place in his or her motivational hierarchy.

Failing that, we strive to find effective therapies that suppress addictive disorders, like therapies we currently have for HIV infection.

And if we cannot achieve that, we search for ways of “managing” addictions so that we limit the damage they cause, perhaps in the way we manage asthma.

Our success at doing any of these things depends on our understanding of what is wrong with the addict. At present we have some idea (for a comprehensive review of theories, see West, 2006).  In a susceptible individual, particular behaviors (mostly drug-taking behaviors) get out of control because they change the individual’s central nervous system (CNS) and/or social and physical environment to increase the motivation to seek out and engage in the activity.

This can be because an artificial “drive” is created; because abstinence becomes unpleasant; because the behavior is very rewarding; because the rewards and punishments associated with the behavior establish powerful habits of thought, feeling, or action; or because the ability or will to resist the motivation to engage in the behavior becomes diminished.

We can go beyond this and say what changes take place in the CNS, what it is about the behaviors that is rewarding, what underpins the unpleasant effects of abstinence, how the social environment changes to promote deepening dependence, and how it is that our propensity to exercise self-control is weakened. We have many plausible hypotheses at varying levels of analysis, from the biochemical to the sociological.

Where has this understanding gotten us so far? We do not yet seem to have any kind of cure for heroin addiction, but with long-term opiate substitution treatments (primarily methadone and buprenorphine) we can often keep it at bay, and with counseling and needle-exchange schemes we can sometimes reduce problematic behaviors (Lingford-Hughes et al, 2004).

For cocaine addiction, we have no demonstrated cure, and no therapy to keep it at bay but counseling may help reduce problematic use (Lingford-Hughes et al, 2004). The same is probably true for amphetamine addiction. For alcohol addiction, arguably some people are cured by a combination of medication and counseling but more commonly it is kept at bay, so that even alcoholics who are “dry” are susceptible to relapse (Lingford-Hughes et al, 2004).

It looks as though nicotine addiction can be cured in perhaps 5 percent of cases by a course of medication, such as nicotine replacement therapy, and in perhaps 10 percent by a combination of medication and what is termed “behavioral support”(Lingford-Hughes et al, 2004). There is little experience of trying to treat this addiction long term or to offer interventions to mitigate the harm.

For gambling addiction, medications that improve or stabilize mood or control impulsiveness and psychological treatments have shown promise, at least in managing the disorder (Toneatto and Millar, 2004).

Conceptualizing Addiction

We may be able to do better than this. It is worth examining in more detail the phenomenon with which we are attempting to deal.

Strangely, there does not seem to be a strong consensus concerning what the phenomenon is. Some researchers regard it as primarily a problem of making maladaptive choices (Skog, 2000), some regard it as a problem of biases in the way people implicitly think about the costs and benefits of the activities (Brown et al, 1987), some focus on powerful feelings of compulsion that addicts experience (Jellinek, 1960), others argue that there is some kind of deficit in the mechanism we use to inhibit responses (Lubman et al, 2004), still others focus on the notion of “habit,”(O’Brien et al, 1992), and yet others place emphasis on how the addict places himself or herself in the social environment (Kearney and O’Sullivan, 2003). 

For some researchers and clinicians, addiction and dependence mean the same thing, while others distinguish between physical dependence and psychological addiction. And I have recently argued for a distinction between addiction (a reward-seeking behavior that has gotten out of control) and the range of different “dependence syndromes” that are associated with different drugs (e.g., tolerance, withdrawal symptoms, narrowing of repertoire, etc.; West, 2006).

It is unlikely that a consensus will emerge because there is no objective way of deciding the issue. There is no pathogen as there is with, say, malaria, and no obvious structural abnormality as there is with a bone fracture.

However, we can build up a picture of the motivational system and the ways in which behavior patterns that we call “addiction” and others that are “addiction-like” emerge. In doing so, perhaps we can gain some new insights that will help us understand the limitations of the treatments we are currently using and ways in which we might improve things for the future.

Plans–Responses–Impulses–Motives–Evaluation: The PRIME Theory of Motivation

A great deal is known about human motivation, but surprisingly, it has not until now been put together into a synthetic theory. Thus there is a wealth of ideas on judgment and decision making, emotions, drives, habits, reflexes, and so on, but these have not been integrated into a model of the motivational system as a whole.

I have attempted to draft such an integration (West, 2006). The result is necessarily complex but there are five unifying themes: the structure of the motivational system, focus on the moment, neural plasticity, the importance of identity, and the unstable mind.

Theme 1: The structure of the motivational system. The first theme is a statement about the overall structure of the “motivational system.”

It is claimed that this system operates at five levels of complexity as shown in Figure 1. At the lowest level are the responses themselves (starting, stopping, or modifying actions). At the next level are impulses and inhibitory forces. These are forces that impel and restrain specific actions and are the final common pathway through which all higher-order motivational elements operate.

Environmental events, emotional states, and internal drives can generate impulses directly (e.g., frustration leading to the impulse to act aggressively, hunger leading to the impulse to eat). If impulses are uncontested we do not experience any feelings associated with them, but if they are held back for any reason, we experience them as “urges.”
 



Figure 2.1. The structure of the motivational system. Responses are generated directly by the internal and external environment, as in reflexes, and by impulses and inhibitory forces. These are influenced directly by the internal and external environment and often also by motives, which are often experienced as feelings of desire or want; these in turn are influenced directly but sometimes by evaluations, which are beliefs about what is good or bad, right or wrong, useful or harmful.

Sometimes we are motivated to form plans, which are mental representations of actions together with some level of intention and starting conditions. Those plans may then later influence motives or evaluations. The external environment is filtered through the internal environment.

Evaluations can influence responses only through motives, which can influence responses only through impulses. This structure gives an inherent advantage to events that directly generate impulses over, for example, those that influence beliefs about what is harmful.

Impulses “push” our behavior. The higher levels of motivation “pull” behavior in the sense that they are future-oriented. First, there are what may be called “motives.” These are mental representations of objects, events, etc., together with a degree of attraction or repulsion attached to them.

These need not be brought to conscious awareness, but when they are we experience them as feelings of “want,” “desire,” or “need.” Attraction and repulsion arise out of anticipated feelings of contentment and distress. If we have conflicting motives, then the one that is strongest at the time will create the impulse to action. That impulse will then compete with any other impulses present at the time to generate the action.

The next level of complexity involves “evaluations.” These are propositional representations about the world as it is or might be that involve some sense of good or bad (useful/detrimental, morally right/wrong, etc.). This theory draws a fundamental distinction between motivational beliefs (evaluations) and feelings (desires and urges). A strong claim of the theory is that evaluations have no direct effect on our actions. They must work through motives and then impulses. The hierarchy of levels of motivation confers a natural advantage on impulses over desires and desires over evaluations in the control of our moment-to-moment behavior.

The fifth and final level of complexity in the structure of motivations is the “plan.” Humans are capable of forming mental representations of actions together with a set of more or less well defined “starting conditions” and a degree of “commitment” to them. This allows for considerably more flexibility of action than would otherwise be possible. Desires that cannot be fulfilled at present because of other priorities or practicalities can be met at a future date. We can also construct plans in anticipation of future events that will deliver opportunities or threats.

The main problem with plans is that they have to be remembered in order to generate the evaluations and motives necessary to control our actions.

Theme 2: The focus on the moment. The second unifying theme is the focus on the “moment.” Our actions at any one time can only be influenced by forces operating at that time. Urges, desires, plans, and evaluations can only affect behavior at the time they are active.

When they are not active, all that exists is the structural configuration of synapses in the CNS that give them the potential to be generated. This self-evident thesis is largely overlooked in theories of motivation that postulate concepts such as “cognition,” “attitude,” and “intention” as stable entities of uncertain epistemological status. The focus in the PRIME theory is on the dynamic and fluid nature of motivation and behavior. Such consistencies as exist in the way we respond to events arise from the fact that the same CNS structural configuration is being acted on by the same inputs to regenerate the same motives.

This provides a very natural basis for explaining why, despite every “intention” to change the way one responds to a situation, very often one finds oneself doing the same thing one did before. It also highlights the critical importance of motivation to avoid or escape from unpleasant thoughts as well as unpleasant experiences: not thinking about things is one of our most widely used coping strategies.

Theme 3: Neural plasticity. The third unifying theme concerns the ways in which the motivational system is altered in the short, medium, and long term by experience. The theory identifies three types of plasticity: habituation/sensitization, in which merely repeating a stimulus makes it less or more attractive or repellent; explicit memory, in which experiences and ideas can be regenerated in a more or less similar form given appropriate cues; and associative learning, which includes classical conditioning (stimulus-stimulus associations) and instrumental conditioning (stimulus-response-reinforcement associations).

Associative learning results in causal connections between patterns of activity in the motivational system (including experiences, feelings, responses) becoming more “habitual,” i.e., rapid and involving less attention.

Theme 4: Identity, self-awareness, and self-control. The fourth unifying theme is the critical importance of “identity” and “self-awareness” and the role that these have in “self-control.” We are obviously capable of forming mental representations of ourselves and equally obviously those mental representations have a special significance. In keeping with the focus on the moment, we need to be attentive to the fact that those mental representations only exist when they are generated and the form they take depends partly on the structural configuration of our CNS and partly on whatever else is going on in our heads at the time.

Like any mental representation, they can be coherent and detailed or incoherent and vague, they can be multifaceted or simple, and they can focus on one feature at one time and other features at other times.

One important influence that our self-concepts have on our motivation stems from evaluation of ourselves. This influences the contentment or distress we feel when we think about ourselves, and how much we like or dislike ourselves.

This has widespread ramifications that affect all self-conscious behavior.