The study found that a person's perception of the swiftness, certainty, and severity of sanctions deterred them from driving under the influence of alcohol (DUI) only when the severity of their addiction to alcohol was not taken into account. When the effects of alcohol addiction were considered, findings showed that individuals with more severe alcohol addiction were less likely to be deterred from DUI regardless of their having been sanctioned in the past. Drivers with less severe alcohol problems, on the other hand, were more likely to be deterred from driving under the influence of alcohol when they had been previously sanctioned. The authors recommend that future research on deterrence theory with respect to DUI introduce key concepts associated with alcohol addiction, such as self-control. Researchers should also include variables other than alcohol addiction that may influence whether being sanctioned for a specific behavior deters a person from repeating that behavior, such as a perception that the sanction is fair. The study involved 433 individuals who had been in alcoholism treatment for at least 6 weeks because of a DUI incident in New York State. Fifty of the treatment providers also participated in the study. The treatment sample provided self-reports on their DUI incidents, impaired driving, future intentions to drive after drinking, and past DUI arrests. DUI arrest data were also obtained from official records. The three measures for perceived deterrence were respondents' perceptions of sanction swiftness, certainty, and severity. Control variables were respondents' age, gender, total number of license suspensions/revocations, and high-risk driving habits, as well as treatment variables. 3 tables and 36 references