According to the recalled notes, Alzheimer's disease is associated with a deficiency in which…

Explanation

Core Concept: Alzheimer's disease is a neurodegenerative disorder characterized by cognitive decline. While acetylcholine deficiency is the primary hallmark, deficits in other neurotransmitters like *serotonin* and norepinephrine also occur, contributing significantly to the neuropsychiatric symptoms (depression, agitation).

Clinical Presentation:

• Memory loss, confusion, mood swings, depression, and behavioral changes.

Diagnosis:

• *First-line:* Cognitive assessments (MMSE, MoCA).
• *Gold Standard:* Clinical diagnosis supported by PET scans (amyloid/tau) and ruling out reversible causes.

Management:

• *Acute:* Manage behavioral and mood symptoms; SSRIs may be used to address depression associated with serotonin deficits.
• *Definitive:* Cholinesterase inhibitors (donepezil) and NMDA receptor antagonists (memantine) for cognitive symptoms.