Behavioral Effects of d-Amphetamine in Humans: Influence of Subclinical Levels of Inattention and Hyperactivity

Objective: Several studies suggest a link between stimulant abuse and attention-deficit hyperactivity disorder (ADHD) symptoms (e. g., inattention and hyperactivity). To further assess the nature of this relationship, the present study examined the association between subclinical symptoms of inattention and hyperactivity and the behavioral effects of d-amphetamine. Methods: Participants were classified into a High-(n = 8) or Low-Score (n = 9) group based on their responses on a rating scale that assessed inattention and hyperactivity symptoms. Results: The participants did not differ across the High-Score and Low-Score groups in their ability to discriminate d-amphetamine. The participants in the High-Score group were significantly more sensitive to the positive participant-rated effects of d-amphetamine (e. g., Good Effects, Like Drug), but less sensitive to drug-induced increases in blood pressure and heart rate. Conclusion: The selective increase in positive subjective effects of d-amphetamine suggests that individuals with subclinical inattention and hyperactivity symptoms may have increased vulnerability to stimulant abuse.