Impulsivity and/or poor impulse control could have an influence on almost all stages of the life cycle of drug use. Theoretically, they could be linked with heightened probability of initiating drug use, of rapidly escalating drug use, of failing to cut down on drug use once it becomes problematic and of relapsing despite motivation to remain abstinent.22, 23, 28–31, 33, 42, 47, 49–54 These contributions can be better understood through a deeper examination of the causal relationships between impulsivity, drug use and addiction, for example whether impulsive tendencies pre-date the onset of drug use behaviors or whether experience with drug use causes or exacerbates the propensity for impulsivity. These directional linkages will be a major topic of this review.
