Which statement about delirium is most accurate?

• A. It has a chronic and progressive course
• B. It is rarely reversible
• C. It is best diagnosed by imaging only
• D. It is typically reversible with prompt treatment and correction of underlying causes

Answer: (D)

Delirium is an acute, fluctuating disturbance of attention and cognition caused by an underlying medical issue, such as infection, dehydration, metabolic disturbance, medication effect, or withdrawal. The key point is that it is usually reversible if you rapidly identify and treat the underlying cause. This differentiates it from dementia, which is chronic and progressive rather than sudden. Diagnosis relies on clinical assessment—looking for sudden onset, impaired attention, and fluctuating level of consciousness—while imaging may be used to rule out structural problems but is not what confirms delirium. Therefore, the statement that delirium is typically reversible with prompt treatment and correction of underlying causes is the most accurate.