Psychostimulant users are sensitive to the stimulant properties of alcohol as indexed by alcohol-induced cardiac reactivity.

One indicator of increased sensitivity to alcohol-induced reward is a heightened heart rate (HR) increase following alcohol intoxication, a characteristic associated with increased alcohol-induced dopamine (DA) release. The goal of this study was to determine whether users of drugs known to induce DA release have higher HR increases after alcohol intoxication than never users have. Sixty-four men with known drug-use histories participated in an alcohol challenge in which HR was measured. Stimulant users had significantly higher ethanol-induced HR increases than never users had, although use of marijuana or hallucinogens was not associated with this marker. Stimulant users obtained superior Sensitivity to Reward scores (R. Torrubia, C. Avila, J. Moltó, & X. Caseras, 2001) compared with never users. Stimulant drug users may be more sensitive to the stimulating properties of alcohol, and this appears to be mediated by superior activity in the Behavioral Approach System (J. A. Gray, 1991).