In the preceding sections, we presented some of the data linking certain manifestations of impulsive behavior (Table 1) to drug-seeking and –taking, and we provided a survey of the involvement of frontostriatal (Figure 1) and monoaminergic mechanisms (Table 2) to these relationships. Perhaps the strongest conclusion to be drawn from this work is that the relationship between impulsivity and addiction-related behaviors is very strong. In human subjects, there appears to be a robust association between both self-report measures of impulsivity, laboratory tests of impulsive behavior and recreational and clinically-impairing patterns of drug and alcohol abuse and dependence. Deficits in action inhibition, waiting, delay discounting and risk-related decision-making are all found in various populations affected by substance use disorders, and burgeoning evidence suggests that some of these deficits (including impairments in action inhibition, delay discounting and risky decision-making) predate the onset of pathological drug-taking (and possibly anticipate all drug use). Research in animal models expands on this data by providing definitive evidence that individual differences in the propensity to engage in impulsive behavior predicts aspects of drug self-administration behaviors, and experience
