An 80-year-old retired teacher presents with a 3-month history of cognitive decline, psychomotor retardation, and poor concentration. She says 'I don't know' to most questions. MMSE is 18/30. She sleeps excessively and has lost 5 kg. Her CT head is normal. Hamilton Depression score is 28. The MOST likely diagnosis is:

• A Alzheimer's dementia
• B Vascular dementia
• C Lewy body dementia
• D Depressive pseudodementia ✓

Explanation

Depressive pseudodementia (Depression-related cognitive impairment) presents with cognitive decline that mirrors dementia but is driven by depression. Key distinguishing features: rapid onset over weeks-months, prominent affective symptoms, patient consistently says 'I don't know' (rather than attempting answers), improvements with antidepressant treatment, and normal neuroimaging. True dementia has insidious onset, neuroimaging changes in later stages, and patient often confabulates rather than saying 'I don't know'.

Reference: Kaplan & Sadock's Synopsis of Psychiatry, 11th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.