Pseudodementia is best described as which of the following?

• A. A true neurodegenerative dementia
• B. A dementia due to depression
• C. A reversible metabolic encephalopathy
• D. A cognitive impairment due to aging

Answer: (B)

Cognition affected by a mood disorder, especially major depression, that imitates dementia is called pseudodementia. The key idea here is that the cognitive problems arise from the mood disorder rather than from a degenerative brain disease, and they can improve when the depression is treated.

In pseudodementia, people often report memory problems and may seem engaged yet perform poorly on cognitive testing, which can be due to decreased effort or loss of motivation rather than an irreversible brain change. Importantly, mood symptoms are present or prominent, and there’s potential for full or substantial reversal of symptoms with effective antidepressant treatment, psychotherapy, or other management of the depression.

This differs from a true neurodegenerative dementia, which tends to have an insidious onset and a progressive course, with less likelihood of rapid reversal after treating mood symptoms alone. It’s also not a reversible metabolic encephalopathy, which would be due to an identifiable metabolic problem (like electrolyte disturbance or organ failure) causing global cognitive decline. Finally, it’s not simply aging-related cognitive decline, which is usually milder and not primarily driven by mood disturbance.

So the best description is cognitive impairment due to depression, which can be reversible with appropriate treatment of the depressive illness.