BEHAVIOURAL CHOICE THEORIES OF ADDICTION

1. BEHAVIOURAL CHOICE THEORIES OF ADDICTION Nick Heather PhD, Centre for Alcohol & Drug Studies, Newcastle, North Tyneside & Northumberland Mental Health NHS Trust, & University of Northumbria

2. THE LANGUAGE OF CHOICE • “Behavioural economics” – a merging of micro-economic theory and a revolution in behavioural psychology beginning in the 1960s (the “matching law”) • “Addiction” is a real phenomenon, not merely a series of causal attributions • Addicts’ choices are predictable • Addicts choose to consume drugs etc. but do not choose to be addicted • Addicts’ choices are constrained – like all choices

3. A DEFINITION OF ADDICTION • “(addiction is shown by) a demonstrated failure to refrain from a behaviour despite attempts to do so or a complaint by the person that the behaviour is out of his or her control.” • Heather, N. (in press). Comments on O-J. Skog, ‘Addiction: definitions and mechanisms’. In R.E. Vuchinich & N. Heather (Eds.), Choice, Behavioural Economics and Addiction. Oxford, UK: Pergamon Press.

4. Other Determinants Other Determinants Other Determinants Other Determinants ABNORMAL DESIRE FOR DRUG OR ACTIVITY (“CRAVING”) AKRASIA OR “WEAKNESS OF WILL” CONCEPTUAL FRAMEWORK FOR EXPLAINING ADDICTION Not Sufficient Not Sufficient NEUROADAPTION OR PRE-EXISTING DIFFERENCES IN NEURAL RESPONSE From: Heather, N. (1998) A conceptual framework for explaining drug addiction, Journal of Psychopharmacology, 12, 3 - 7

5. GEORGE AINSLIE’S THEORY • Ainslie, G. (1992). Picoeconomics: The Strategic Interaction of Successive Motivational States Within The Person. Cambridge, UK: Cambridge University Press. • Ainslie, G. (2000). Breakdown of Will. Cambridge, UK: Cambridge University Press. • Anslie, G. & Monterosso, J. (in press). Hyperbolic discounting as a factor in addiction: a critical analysis. In R.E. Vuchinich & N. Heather (Eds.), Choice, Behavioural Economics and Addiction. Oxford, UK: Pergamon Press.

6. Value Time HYPERBOLIC DISCOUNT CURVES BEHAVIOURAL CHOICE THEORIES Hyperbolic discount curves from two rewards of different sizes available at different times (vertical dashed lines). The smaller-sooner reward is temporarily valued higher (preferred) for a period just before it’s available, as shown by the portion of its curve that projects above that of the later-larger reward. Where V is value, A is the undiscounted reward value, D is delay and k is a constant describing the individual subjects degree of impatience. Functions in this class are referred to as hyperbolic as contrasted with exponential functions which model temporal discounting as occurring at a fixed rate over time. A 1 + kD V=

7. FOUR WAYS TO MAKE THE “SELF-CONTROLLED” CHOICE • Extrapsychic mechanisms (e.g. “precommitment”) • Control of attention • Preparation of emotion • Personal rules (i.e., “will-power”)

8. THE MELIORATION THEORY OF ADDICTION • Herrnstein, R.J., & Prelec, D. (1992). A theory of addiction. In G. Loewenstein & J. Elster (Eds.), Choice Over Time (pp. 331-360). New York: Russell Sage Foundation. • Heyman, G.M. (in press). Consumption dependent changes in reward value: a framework for understanding addiction. In R.E. Vuchinich & N. Heather (Eds.), Choice, Behavioural Economics and Addiction. Oxford, UK: Pergamon Press.

9. MELIORATION ADDICTION BEHAVIOURAL CHOICE THEORIES Melioration Addiction 2 Local Utility of Drug Consumption Overall Utility 1 3 Local Utility of Other Activities 4 Abstinence Heavy drug use Relative Behavioural Allocation to Drug Consumption [Drug Consumption/ (Drug Consumption + Other Activities)]

10. RATIONAL ADDICTION • Becker, G.S., & Murphy, K.M. (1988). A theory of rational addiction. Journal of Political Economy, 96, 675-700. • Skog, O.-J. (1999). Rationality, irrationality and addiction: notes on Becker and Murphy's theory of addiction. In J. Elster and O.-J. Skog (Eds.), Getting Hooked: Rationality and Addiction. Cambridge, Cambridge University Press: 173-207. • Chaloupka, F.J., Emery, S. & Liang, L. (in press). Evolving models of addictive behavior: from neoclassical to behavioral economics. In R.E. Vuchinich & N. Heather (Eds.), Choice, Behavioural Economics and Addiction. Oxford, UK: Pergamon Press.

11. RATIONAL ADDICTION BEHAVIOURAL CHOICE THEORIES Rational Addiction Utility of Drug Consumption 2 1 3 Utility of Other Activities Marginal Utility of Drug Consumption 4 Abstinence (No Stock) Heavy Drug Use (High Stock) Stock of Addictive Capital

12. RACHLIN’S RELATIVE THEORY OF ADDICTION • Rachlin, H. (1997). Four teleological theories of addiction. Psychonomic Bulletin and Review, 4, 462-473. • Rachlin, H. (2000). The Science of Self-control. Cambridge, MA: Harvard University Press. • Rachlin, H. (in press). Economic concepts in the behavioural study of addiction. In R.E. Vuchinich & N. Heather (Eds.), Choice, Behavioural Economics and Addiction. Oxford, UK: Pergamon Press.

13. 2 1 Price Habituation of Drug Consumption 3 Price sensitization of Social Interaction 4 Less drug use/ more socialization More drug use/ less socialization RELATIVE ADDICTION BEHAVIOURAL CHOICE THEORIES Relative Addiction Relative Behavioural Allocation to Drug Consumption and Social Interaction

14. APPLICATIONS TO TREATMENT (1) • Ainslie’s theory obviously relevant to self-control or self-management techniques developed in early 1970s (e.g., Mahoney and Thoresen 1974; Thoresen and Mahoney 1974) • Also relevant to cognitive therapy (e.g., Beck et al. 1993) • May also be relevant to the “mechanism” of motivational interviewing • Several aspects of modern cognitive-behavioural approaches to treatment can be interpreted within a behavioural economics framework (e.g. self-efficacy, relapse prevention)

15. APPLICATIONS TO TREATMENT (2) • Behavioural economic principles more generally have been applied successfully to contingency management programs (e.g. Community Reinforcement Approach) – see work of Bickel, Higgins and colleagues • But can these “reframings” of existing treatment modalities lead to improvements in effectiveness? • And can the behavioural economic perspective lead to quite novel methods of treatment?

16. APPLICATIONS TO PUBLIC HEALTH AND THE ORGANISATION OF TREATMENT SERVICES (1) • Tucker, J.A. & Simpson, C.A. (in press). Merging behavioural economic and public health approaches to the delivery of services for substance abuse: concepts and applications. In R.E. Vuchinich & N. Heather (Eds.), Choice, Behavioural Economics and Addiction. Oxford, UK: Pergamon Press. • Ways of closing the currently existing gap between need and utilization and policies for allocating limited intervention resources in a more cost-effective manner across the population in need. • Perhaps the main advantage of the behavioural economic perspective over other perspectives on service provision is its inherent emphasis on behavioural alternatives to addiction.

17. APPLICATIONS TO PUBLIC HEALTH AND THE ORGANISATION OF TREATMENT SERVICES (2) • Applying the behavioural economic perspective to the organization of treatment services views care-seeking and adherence as choice processes. • To facilitate care-seeking and adherence one should attempt to make services more attractive and easier to access, and thus very different from the intense, high-threshold services that have dominated addiction treatment in the past.

18. APPLICATIONS TO PREVENTION AND PUBLIC POLICY • McCoun, R. (in press). Is the addiction concept useful for drug policy? In R.E. Vuchinich & N. Heather (Eds.), Choice, Behavioural Economics and Addiction. Oxford, UK: Pergamon Press. • McCoun’s answer is “No” and that applies too to behavioural choice theories of addiction. • Behavioural choice theories have the implication that increases in the price of addictive substances will lead to lower levels of use and therefore harm. But that again is hardly novel.

19. POTENTIAL USEFULNESS OF BEHAVIOURAL CHOICE THEORIES • “There is nothing so useful as a good theory” (Kurt Lewin, 1951) • i.e., if a theory provides an accurate and adequate explanation for the occurrence of an observable phenomenon, it must, by definition, contain within it the means of changing that phenomenon • It may be that the main influence of behavioural choice theories will be, not on the “technology” of treatment or public health and prevention policies, but on the way addiction is generally understood