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

Area of Science:

• Neurology
• Psychiatry
• Geriatrics

Background:

• The Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) criteria for delirium encompass a heterogeneous patient population.
• Diverse risk factors and causes of delirium complicate the search for uniform diagnostic biomarkers.
• Distinguishing delirium from dementia and coma using current DSM-5 criteria remains a clinical challenge.

Purpose of the Study:

• To highlight the heterogeneity within delirium diagnoses based on DSM-5 criteria.
• To caution against the pursuit of single, universal biomarkers for delirium.
• To advocate for personalized management strategies in clinical practice.

Main Methods:

• Review of current Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) criteria for delirium.
• Analysis of patient heterogeneity in terms of risk factors and causes.
• Conceptual discussion on the implications for biomarker research and clinical diagnosis.

Main Results:

• The DSM-5 criteria for delirium group together patients with widely varying underlying causes and risk factors.
• The heterogeneity of delirium makes the development of a single, reliable diagnostic biomarker unlikely.
• Clinical differentiation of delirium from dementia and coma using DSM-5 criteria presents ongoing difficulties.

Conclusions:

• A single biomarker is unlikely to be effective for diagnosing delirium due to patient heterogeneity.
• Future research should acknowledge and address the diverse nature of delirium.
• Improving patient outcomes likely depends on interprofessional, personalized management and continuous monitoring of vulnerable individuals.