Table 4.
Failure modes in the decision-making system provide a taxonomy of vulnerabilities to addiction
| Failure Point | Description | Key Systems | Clinical Consequence |
|---|---|---|---|
| Vulnerability 1 | Moving away from homeostasis | Planning | Withdrawal |
| Vulnerability 2 | Changing allostatic set points | Planning | Changed physiological set points, craving |
| Vulnerability 3 | Mimicking reward | Planning | Incorrect action-selection, craving. |
| Vulnerability 4 | Sensitization of motivation | Planning | Incorrect action-selection, craving. |
| Vulnerability 5 | Increased likelihood of retrieving a specific relation | Planning | Obsession |
| Vulnerability 6a | Misclassification of situations: overcategorization | Situation-recognition | Illusion of control, hindsight bias |
| Vulnerability 6b | Misclassification of situations: overgeneralization | Situation-recognition | Perseveration in the face of losses |
| Vulnerability 7 | Overvaluation of actions | Habit | Automated, robotic drug-use |
| Vulnerability 8 | Selective inhibition of the planning system | System-Selection | Fast development of habit learning |
| Vulnerability 9 | Overfast discounting processes | Planning, habit | Impulsivity |
| Vulnerability 10 | Changes in learning rates | Planning, habit | Excess drug-related cue associations |
Note. Because Vulnerability 6 affects the situation S term in both planning and habit systems, we identify it as affecting “situation-recognition.” Vulnerability 8 affects the interaction between the planning and habit systems. Vulnerabilities 9 and 10 can affect components of the planning and habit systems. Detailed models of the effects of these last two vulnerabilities on the systems are as yet unavailable.