The model of addiction proposed by Redish et al. shows a lack of fit with recent data and models in psychological studies of addiction. In these dual process models, relatively automatic appetitive processes are distinguished from explicit goal-directed expectancies and motives, whereas these are all grouped together in the planning system in the Redish et al. model. Implications are discussed.

The understanding of decision-making systems has come together in recent years to form a unified theory of decision-making in the mammalian brain as arising from multiple, interacting systems (a planning system, a habit system, and a situation-recognition system). This unified decision-making system has multiple potential access points through which it can be driven to make maladaptive choices, particularly choices that entail seeking of certain drugs or behaviors. We identify 10 key vulnerabilities in the system: (1) moving away from homeostasis, (2) (...) changing allostatic set points, (3) euphorigenic signals, (4) overvaluation in the planning system, (5) incorrect search of situation-action-outcome relationships, (6) misclassification of situations, (7) overvaluation in the habit system, (8) a mismatch in the balance of the two decision systems, (9) over-fast discounting processes, and (10) changed learning rates. These vulnerabilities provide a taxonomy of potential problems with decision-making systems. Although each vulnerability can drive an agent to return to the addictive choice, each vulnerability also implies a characteristic symptomology. Different drugs, different behaviors, and different individuals are likely to access different vulnerabilities. This has implications for an individual's susceptibility to addiction and the transition to addiction, for the potential for relapse, and for the potential for treatment. (shrink)

Addictive behaviour has qualities that make it ideal for study using implicit techniques. Addictive behaviours are mediated in part by automatic responses to drug cues, and there is sometimes social pressure to distort self-reports. However, relationships between implicit attitudes and addictive behaviours have been inconsistent. Using a new implicit measure, the affect misattribution procedure (AMP), we found consistent evidence that drinking-related behaviours are systematically related to implicit attitudes. The procedure predicted a behavioural choice to drink beer and self-reported typical drinking (...) tendencies, including hazardous drinking and alcohol-related problems. The AMP showed larger relationships with drinking behaviour than other implicit measures, and explained unique variance in drinking beyond those measures and beyond explicit measures. Though self-presentation distorted self-reports, it did not affect AMP scores. These studies highlight the importance of automatic affective responses in addictive behaviour and suggest a useful means for measuring those responses. (shrink)

The model proposed by Redish et al. considers vulnerabilities within decision systems based on expectancy-value assumptions. Further understanding of processes leading to addiction can be gained by considering other inputs to decision-making, particularly affective associations with behaviors. This consideration suggests additional decision-making vulnerabilities that might explain addictive behaviors.

The consideration of gambling as a decision-making disorder may fail to explain why the majority of people gamble, yet only a small percentage of people lose control of their behaviour to the point where their gambling becomes problematic. The application of dual process theories to gambling addiction offers a means of explaining the differences between and gambling, augmenting the multiple vulnerabilities proposed by Redish et al.