Delirium is distinguished from dementia by its

Delirium is distinguished from dementia by its

• A. Chronic progressive decline
• B. Acute onset with fluctuating course
• C. Mood disorder features
• D. Memory loss only

Answer: (B)

Delirium is defined by an abrupt change in mental status with fluctuations in attention and awareness over a short period, often reversing when the underlying cause is treated. This acute onset and the waxing and waning of consciousness and attention set it apart from dementia, which shows a gradual, chronic decline in cognitive function, especially memory, over months to years. The other options don’t fit because chronic progressive decline describes dementia rather than delirium, mood disorder features are not the defining hallmark of delirium, and memory loss alone does not capture the essential disturbance in attention and consciousness that characterizes delirium.

Delirium is defined by an abrupt change in mental status with fluctuations in attention and awareness over a short period, often reversing when the underlying cause is treated. This acute onset and the waxing and waning of consciousness and attention set it apart from dementia, which shows a gradual, chronic decline in cognitive function, especially memory, over months to years. The other options don’t fit because chronic progressive decline describes dementia rather than delirium, mood disorder features are not the defining hallmark of delirium, and memory loss alone does not capture the essential disturbance in attention and consciousness that characterizes delirium.