E Pluribus Unum

“Out of many, one. ” The United States’ motto is fitting for the field of delirium because delirium research is coming into its own. Delirium is now recognized as a major factor in the hospital and recovery course of older adults. No longer considered a “reversible epiphenomenon” that can be taken for granted, the complexity of delirium asserts itself whenever it is closely examined. This complexity justifies, and even demands, broad, collaborative work. As delirium science develops, now is the time to form a unifying collaboration to improve delirium science, education, and clinical care around the world. The purpose of this article is to illuminate the potential for collaborative efforts within the United States and with partners around the world for research and clinical advances in the understanding of delirium. Multiple aspects of delirium remain poorly understood, just a few of which include its pathophysiology, how we can truly improve recognition, how best to screen for it, how to effectively communicate its dire effect on patient outcomes, and its natural history. Do deliriums due to metabolic problems such as hyponatremia present differently, and result in different outcomes, than those that are primarily due to medication? Given our current assumption that delirium presents when the most basic bodily systems break down, how do we account for subdelirium, unless delirium presents along a spectrum? What causes of delirium underlie fluctuation? Why do some individuals become delirious, when others who have similar medical burdens of illness do not? How many subcategories of delirium should we consider? Not least, the range of pharmacological trials that are placebo controlled, randomized, and double blinded remains the most narrow of all psychiatric and medical illnesses of late life. And although we assume that the phenomenology of delirium, which most likely reflects a biological process, would be similar everywhere, this concept has never been tested, yet given that health depends on social, financial, and environmental support, as well as cultural constructs that define illness, there is no objective reason why this must be so. Until the last few years, collaborations in the field were rare, and investigators were often isolated—few and far between. This situation has begun to be addressed more formally with the development of the European Delirium Association (EDA), which itself sprang from a meeting at Duke University in 2005. Since then, the EDA has held yearly meetings. The first, held in Alkmaar, the Netherlands, in 2006, hosted approximately 40 participants. The most recent, in Amsterdam, the Netherlands, in November 2010, hosted approximately 150. We can now observe a burgeoning cluster of multiple, highly productive investigative enterprises that span national boundaries in Europe and that have begun to involve sites in the United States and elsewhere. Publications have arisen from such diverse origins as Thailand, Australia, Jordan, China, and Japan, offering opportunities to share ideas among academic groups that may have significantly different clinical perspectives. It appears that the “output curve” of studies in the field has become even steeper since the establishment of the EDA. The American Delirium Society was founded even as this supplement was prepared for submission. Our colleagues in Europe, who have offered advice and assistance, have already received it most warmly. At the recent EDA meeting, several discussions indicated interest in joint meetings, as well as the hope that ADS could expand to have North American representation. Others discussed the prospects of worldwide delirium collaborations. Given the significant effect on healthcare resource utilization and outcomes associated with delirium, there is a dire need to develop collaborative enterprises that will improve efficiency by providing shared resources and knowledge. With academic and grant support, such interactions will be essential to support this fledgling field. What areas seem ripe for collaborative or multisite work? (1) Multiple centers in Europe and the United States have begun projects related to the pathophysiology of delirium. Alasdair MacLullich and colleagues (Edinburgh, Scotland) have begun to address the role that aberrant stress responses may play. Colm Cunningham and Durham Veterans Affairs Medical Center, Duke University, Durham, North Carolina.