Fig. 1.

Mean ratings on the BAES Stimulant scale assessed before and four times after 10-mg d-amphetamine, for three responder groups, defined using tertiles of the distribution of change scores on this scale (Stim = 1.5 h – baseline): Responders, change score ≥ 7, n = 63; Average Responders, change score > −4 and < 7, n = 64; Nonresponders, change score ≤ −4, n = 65. By definition, the groups exhibited distinct stimulant responses to amphetamine, and the differences were most evident at 1.5 h post-drug. Note that this figure is presented for illustrative purposes, to convey the magnitude of and variation in the stimulant response. In the statistical analyses, Stim was treated as a continuous predictor variable. BAES = Biphasic Alcohol Effects Scale.