A mathematical model of alcohol consumption, which characterizes individual drinking in terms of frequency of consumption and subsequent loss of control drinking once consumption has been initiated, is introduced. The model provides a conceptual link between behavioral indices of alcohol consumption patterns and theoretical models of the role of loss of control drinking in the genesis of alcohol dependence and alcoholism. Based on data from a large sample of first offender drunk drivers, it is shown that specific measures of consumption patterns can be used to provide individual estimates of parameters of the model. These estimates are shown to be strongly related to one measure of alcohol dependence and to introspective reports of loss of control drinking.