There is considerable evidence that externalizing disorders, such as ADHD, increase risk for alcohol and other drug use. ADHD is characterized by disinhibited or undercontrolled behavior and attention, and these deficits in control are suspected to contribute to the increased risk for alcohol abuse in this population. Further, alcohol itself is well-known for its acute impairing effects on cognitive processes involved in the regulation of behavior and attention. Yet, little research has examined how inhibitory and attentional deficits in individuals with ADHD might lead to heightened sensitivity to alcohol's acute disinhibiting effects. Because individuals with ADHD are at risk for alcohol abuse, it is important to examine this potentially heightened sensitivity to the drug, as well as to test how reduced control in response to alcohol might confer increased risk for abuse within this population. The proposed project will examine sensitivity to alcohol-induced increases in disinhibition and attentional bias towards alcohol-related stimuli in non-dependent adults with ADHD and a comparison group of non-dependent healthy adults as well as examine individual differences in sensitivity of these mechanisms in relation to abuse potential. The study will test the effects of controlled doses of alcohol on cognitive performance tasks that measure inhibitory control and attentional bias and examine the contribution of these measures to ad lib alcohol consumption. The findings will provide an understanding of how susceptibility to alcohol's acute behavioral-impairing effects might confer increased risk for alcohol dependence in drinkers characterized by deficits in behavioral control by promoting a continued pattern of abusive binge drinking. This will provide important information concerning mechanisms through which the acute effects of the drug contribute to its abuse potential.