Which of the following symptoms is most characteristic of nocturnal delirium?

A. Progressive loss of language skills is more characteristic of dementia, particularly language-predominant types like primary progressive aphasia, rather than nocturnal delirium. It develops gradually over months to years, not acutely. B. Gradual memory decline is also a hallmark of dementia, such as Alzheimer’s disease, where cognitive deficits evolve slowly over time. This is not consistent with the acute and fluctuating nature of delirium. C. Acute onset of confusion during the evening hours is correct. nocturnal delirium, often called sundowning, is characterized by sudden confusion, agitation, or disorientation that occurs primarily in the late afternoon or evening. This symptom is acute and fluctuates, distinguishing it from the gradual cognitive decline seen in dementia. Factors such as reduced lighting, fatigue, and disruption of circadian rhythms contribute to this phenomenon. D. Persistent depressive symptoms indicate a mood disorder, not nocturnal delirium. While delirium can co-occur with depression, persistent depressive symptoms do not describe the hallmark evening-onset confusion and agitation that define nocturnal delirium.