Intravenous administration of haloperidol to healthy volunteers: Lack of subjective effects but clear objective effects

Healthy volunteers who received i.v. injections of either saline or haloperidol (0.5 or 1.0 mg) made visual analogue scale ratings of subjective mood, tension, shakiness and the global feeling of having received an active drug. The subjective ratings of volunteers who received haloperidol did not differ, overall, from those who received saline. In contrast, the drug caused clear objective changes in several psychological tests. I.v. administration of low doses of haloperidol may permit double-blind testing of the psychological actions of haloperidol in healthy volunteers.