The behavioral economics of substance use disorders: reinforcement pathologies and their repair

Abstract

The field of behavioral economics has made important inroads into the understanding of substance use disorders through the concept of reinforcer pathology. Reinforcer pathology refers to the joint effects of (a) the persistently high valuation of a reinforcer, broadly defined to include tangible commodities and experiences, and/or (b) the excessive preference for the immediate acquisition or consumption of a commodity despite long-term negative outcomes. From this perspective, reinforcer pathology results from the recursive interactions of endogenous person-level variables and exogenous environment-level factors. The current review describes the basic principles of behavioral economics that are central to reinforcer pathology, the processes that engender reinforcer pathology, and the approaches and procedures that can repair reinforcement pathologies. The overall goal of this review is to present a new understanding of substance use disorders as viewed by recent advances in behavioral economics.

Figure 1

Panel a shows demand curves for two hypothetical reinforcers. Although both reinforcers show the same intensity of demand (level of consumption when the commodity is available at very low prices), the reinforcer represented by open red squares shows higher elasticity (sensitivity to price) compared with the reinforcer represented by closed blue circles. Panel b shows demand curve (closed blue circles; left y-axis) and corresponding response output curve (open red circles; right y-axis). Also shown are the price at which maximal responding occurs (P_max) and the corresponding maximal response output (O_max).

Figure 2

Hypothetical delay-discounting function. Reward value decreases in a hyperbolic fashion as delay until receipt of the reward increases.

Figure 3

Panel a shows that assuming exponential discounting, relative reward (preference) between a smaller-sooner (blue) and larger-later (red) reward remains constant through time (e.g., at both Time A and Time B). Panel b shows that assuming hyperbolic discounting, preference reverses from a larger-later (red) reward (at Time A) to a smaller-sooner (blue) reward (Time B).

Figure 4

Mean (±1 standard error of the mean) hypothetical consumption values across 17 different prices for alcohol purchases associated with three next-day responsibility conditions: (diamonds) no next-day responsibilities, (squares) next-day class, and (triangles) next-day test. From Skidmore JR, Murphy JG. 2011. The effect of drink price and next-day responsibilities on college student drinking: a behavioral economic analysis. Psychol. Addict. Behav. 25:57–68. Reprinted with permission from the American Psychological Association.

Figure 5

Changes in past-month number of alcohol problems from baseline to follow-up by intervention condition. Error bars reflect ±1 standard error of the mean. Abbreviation: SFAS, substance-free activity session. From Murphy JG, Dennhardt AA, Skidmore JR, Borsari B, Barnett NP, et al. 2012. A randomized controlled trial of a behavioral economic supplement to brief motivational interventions for college drinking. J. Consult. Clin. Psychol. 80:876–86. Reprinted with permission from the American Psychological Association.