[Heterogeneity of delirium cannot be captured by a simple diagnostic instrument].

The latest criteria for delirium (DSM-5) still encompass a very heterogeneous group of patients, as both risk factors and causes differ greatly between patients. This makes it unlikely that a single biomarker (e.g. an EEG signal) can be a valid and reliable diagnostic tool in clinical practice. Researchers should be very aware of this heterogeneity, as striving for uniform biomarkers would otherwise result in a considerable waste of research effort. In clinical practice, the delineation of delirium syndrome from dementia and coma using these DSM-5 criteria remains challenging. We state that patient outcomes can probably be improved most by interprofessional, personalised management and the monitoring of vulnerable patients during their individual disease trajectories.