Critically ill patients with subsyndromal delirium (ICDSC 1-3) are also at risk for substantial morbidity and mortality and are at high risk for developing delirium (ICDSC ≥ 4). Recent studies suggest that the administration of low-dose antipsychotic therapy to non-ICU patients at risk for delirium prevents transition to delirium, reduces delirium severity and shortens length of hospital stay without causing adverse effects. Given that up 1.5 million Americans may develop subsyndromal delirium each year, an intervention that is found to be safe and effective, particularly if it is of low cost, will have a profound impact on the U.S. healthcare system.