High sensation seekers reported stronger subjective responses to d-amphetamine in one experiment, while measured attention, inhibition and risk-taking did not show the same group differentiation. Sensitivity to feeling a drug and sensitivity on a cognitive task were distinct findings.
The human study recruited healthy volunteers from the upper and lower quartiles of an impulsive sensation-seeking scale using age- and sex-adjusted norms. Participants received placebo and oral d-amphetamine doses of 7.5 and 15 mg per 70 kg under double-blind conditions.
The randomized-block outpatient design assessed subjective, cardiovascular and performance outcomes. Drug condition was experimentally manipulated, while the personality grouping itself was measured rather than randomized.
High impulsive sensation seekers showed greater increases on selected ratings such as feeling the drug, liking it and feeling high. However, the paper reported no corresponding group differences in baseline performance or drug effects on the attention, inhibition and risk-taking measures.
That pattern does not establish identical performance in all circumstances. A nonsignificant moderator comparison can be imprecise. It does, however, prevent using the subjective difference as evidence that the same personality groups necessarily experienced different cognitive enhancement or impairment.
Personality measures can contain several components, and their interpretation depends on recruitment and scoring. Extreme-quartile sampling, a selected healthy population, limited doses and specific tasks restrict generalization to people with stimulant dependence or to nonoral use.
The paper’s discussion of vulnerability is a proposed pathway, not a prospective demonstration of who later developed a disorder. It also does not validate personality as a substitute for observed functioning. Subjective reward, cognitive performance, reinforcement, biological exposure and individual impairment require their own evidence rather than being inferred from one another.
Read our analysis of personality associations with euphoria and arousal.
Individual differences in drug abuse vulnerability: d-Amphetamine and sensation-seeking status. doi:10.1007/s00213-006-0487-z.