In the paper, G. Grunder et al., Time Course of 5-HT2A Receptor Occupancy in the Human Brain after a Single Oral Dose of the Putative Antipsychotic Drug MDL 100,907 Measured by Positron Emission Tomography, Neuropsychopharmacology 17:175–185, 1997, the authors regret that QD was incorrectly shown as QID on page 184, line 20. The sentence should read, “The data from this study suggest that MDL 100,197 at 20 mg QD would be appropriate for an initial therapeutic dose and regimen.”