| Acute administration of the stimulant d-amphetamine produces multiple biochemical, physiological, mood, and cognitive changes similar to those seen in mania. The present study investigated the effects of 25 mg of oral d-amphetamine on physiological (blood pressure and heart rate), cognitive (reaction time and errors), subjective (mood) and biochemical (plasma amphetamine, homovanillic acid, 5-hydroxyindole-acetic-3acid, gamma-aminobutyric acid, glutamate and tryptophan) changes in 25 healthy male volunteers (18--45 years) using a double-blind, placebo-controlled crossover design over 8 hours. An existing method was modified using electron-capture gas chromatography to measure plasma amphetamine levels. As well, a novel reaction time test was developed to measure time-dependent changes in selective attention and vigilance. Results indicated that peak levels of amphetamine occurred at 3.5 hours and decreased over the subsequent time period studied. These changes were mirrored in subjective, cognitive, and blood pressure changes. The changes seen in biochemicals were inconclusive although a similar pattern was observed. |
