What are the defining features of delirium?

What are the defining features of delirium?

• A. Disturbance in attention and awareness, acute onset, fluctuating course, and additional cognitive disturbances; evidence from a medical condition, substance use, or other etiologies.
• B. Persistent sleep difficulties.
• C. Elevated mood and increased energy.
• D. Altered personality.

Answer: (A)

Delirium is defined by an abrupt disturbance in attention and awareness that develops over hours to days and tends to fluctuate in severity during the day. In addition, there are deficits in at least one other cognitive domain, such as memory, language, perception, or visuospatial ability. Crucially, there is evidence that this disturbance is caused by an underlying medical condition, substance intoxication or withdrawal, or another physiological factor. These features—acute onset, fluctuating course, impairment in attention and awareness, and a clear medical or substance-related etiology—distinguish delirium from other conditions. By comparison, persistent sleep difficulties describe insomnia, elevated mood and increased energy align with mania, and altered personality implies a more long-standing pattern rather than an acute, etiologically linked change.

Delirium is defined by an abrupt disturbance in attention and awareness that develops over hours to days and tends to fluctuate in severity during the day. In addition, there are deficits in at least one other cognitive domain, such as memory, language, perception, or visuospatial ability. Crucially, there is evidence that this disturbance is caused by an underlying medical condition, substance intoxication or withdrawal, or another physiological factor. These features—acute onset, fluctuating course, impairment in attention and awareness, and a clear medical or substance-related etiology—distinguish delirium from other conditions. By comparison, persistent sleep difficulties describe insomnia, elevated mood and increased energy align with mania, and altered personality implies a more long-standing pattern rather than an acute, etiologically linked change.