Debating the Role of Arousal in Delirium Diagnosis: Should Delirium Diagnosis Be Inclusive or Restrictive?

Delirium is common in acute, postacute, and long-term care settings, and it can be difficult to recognize, especially without deliberate mental status evaluation. Because delirium typically presents with altered arousal and arousal can be assessed within a matter of seconds, routine assessment of arousal offers an efficient means of delirium screening. Nevertheless, impaired arousal often precludes formal assessment of attention and awareness, the cardinal features of delirium per the current Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. Here we debate the relative merits of "ruling in" as delirious noncomatose patients with impaired arousal (inclusive approach) vs reserving delirium diagnosis to patients in whom diagnostic criteria can be elicited (restrictive approach). Inclusivism provides efficiency and may prevent missing or delaying delirium diagnosis. The restrictive approach challenges the utility of ruling such patients in as delirious and advocates for identifying mental states that directly inform clinical care. Both positions, however, firmly emphasize the value of routine clinical assessment of arousal.