Which of the following is not a characteristic of delirium?

The characteristic that patients with delirium typically exhibit is a lack of coherence in their thoughts and speech. In contrast, patients may demonstrate disorientation and confusion, making it difficult for them to engage in coherent conversation. This lack of thorough comprehension and logical thought processes is a hallmark of delirium.

Delirium is often characterized by a sudden onset of symptoms, which can fluctuate throughout the day, particularly worsening during the evenings or nighttime, known as sundowning. Additionally, the duration of delirium is generally brief, often resolving once the underlying cause is treated. Thus, the assertion that the patient is coherent does not align with the defining characteristics of delirium.