Acute subjective responses to paroxetine in normal volunteers

The purpose of this study was to compare the subjective effects of the selective serotonin reuptake inhibitor, paroxetine, to those of the prototypic stimulant, d-amphetamine. Ten healthy volunteers attended 5 sessions and received paroxetine (10, 20, 50 mg), d-amphetamine (20 mg), and placebo. Subjective effects were measured at regular intervals for 26-30 h. Paroxetine and d-amphetamine produced highly dissimilar effects on mood. For example, whereas d-amphetamine increased ratings of euphoria, drug high, and desire for drug, paroxetine produced no effects on these measures. Conversely, whereas paroxetine increased ratings of Confusion and Fatigue, d-amphetamine did not. These findings suggest that serotonin does not play a significant role in mediating the positive subjective effects of stimulant drugs.