In an 82‑year‑old man with agitation, aggression, and recent forgetfulness, what diagnosis should be suspected and how should it be managed?

Suspect Dementia with Delirium and Treat Systematically

In an 82-year-old man presenting with agitation, aggression, and forgetfulness, suspect dementia (most likely Alzheimer's disease) with superimposed delirium, and immediately investigate reversible medical causes before considering any pharmacological intervention. 1, 2

Immediate Diagnostic Priorities

Distinguish Delirium from Dementia Alone

• Delirium develops acutely over hours to days with fluctuating symptoms throughout the day, while dementia progresses gradually over months to years with stable daily presentation 3
• Interview a knowledgeable informant to establish the exact timeline of when confusion started—ask specifically when symptoms began, whether confusion fluctuates during the day, and if there are lucid intervals when the patient seems more alert 3
• Hypoactive delirium is the most commonly missed subtype in elderly patients and carries higher mortality risk than hyperactive delirium—it may present with cognitive slowing, sedated appearance, and nighttime confusion mistakenly attributed to baseline dementia 3
• Use a two-step screening process: Delirium Triage Screen (very sensitive) followed by Brief Confusion Assessment Method (very specific), and repeat screening every 8-12 hours as mental status fluctuates 2, 3

Systematically Investigate Reversible Medical Causes

Before any medication, aggressively search for and treat medical triggers that commonly drive behavioral symptoms in dementia patients who cannot verbally communicate discomfort: 4

• Infections: Check for urinary tract infections and pneumonia—over 80% of patients with bacteremia show neurological symptoms ranging from lethargy to coma 2
• Pain: Assess and treat pain systematically, as untreated pain is a major contributor to behavioral disturbances in patients who cannot verbally communicate discomfort 4
• Constipation and urinary retention: Both significantly contribute to restlessness and aggression 4
• Metabolic disturbances: Check for dehydration, electrolyte abnormalities (especially hyponatremia and hypercalcemia), hypoxia, and hyperglycemia 2
• Medication review: Identify and discontinue anticholinergic medications (diphenhydramine, hydroxyzine, oxybutynin, cyclobenzaprine) and benzodiazepines, which are potent precipitants of delirium 4, 2
• Sensory impairments: Ensure the patient uses glasses and hearing aids, as visual and hearing impairments contribute significantly to delirium 2

Non-Pharmacological Interventions (First-Line Treatment)

Non-pharmacological multicomponent interventions are the primary and first-line approach, with strong evidence supporting their effectiveness and essentially no risk of harm: 2

• Cognitive reorientation: Regularly orient to person, place, time, and situation using simple, clear instructions with visual cues 2
• Environmental modifications: Ensure adequate lighting (especially during late afternoon to prevent sundowning), reduce excessive noise, simplify the environment by reducing clutter, and use clearly labeled, color-coded storage 4
• Communication strategies: Use calm tones, simple one-step commands, and gentle touch for reassurance—allow adequate time for the patient to process information before expecting a response 4
• Sleep enhancement: Implement non-pharmacological sleep protocols, increase daytime bright light exposure (2 hours of morning bright light at 3,000-5,000 lux), avoid bright light in the evening, and reduce time in bed during the day 4, 2
• Early mobility: Provide physical rehabilitation and exercise distributed throughout the day in short sessions, with at least 30 minutes of sunlight exposure daily 4, 2
• Establish predictable daily routines: Structured daily schedules for meals, exercise, and bedtime reduce confusion and anxiety 4
• Caregiver education: Educate caregivers that behaviors are symptoms of dementia, not intentional actions, to promote empathy and understanding 4

Pharmacological Treatment (Only After Non-Pharmacological Approaches Fail)

When to Consider Medication

Medications should only be used when the patient is severely agitated, threatening substantial harm to self or others, and behavioral interventions have been thoroughly attempted and documented as insufficient. 4

First-Line Pharmacological Option: SSRIs for Chronic Agitation

For chronic agitation without psychotic features, SSRIs are the preferred first-line pharmacological option: 4

• Citalopram: Start 10 mg/day, maximum 40 mg/day 4
• Sertraline: Start 25-50 mg/day, maximum 200 mg/day 4
• Evaluate response within 4 weeks using quantitative measures (Cohen-Mansfield Agitation Inventory or NPI-Q) 4
• If no clinically significant response after 4 weeks at adequate dose, taper and withdraw the medication 4
• SSRIs significantly reduce overall neuropsychiatric symptoms, agitation, and depression in patients with vascular cognitive impairment and dementia 4

Second-Line: Antipsychotics for Severe Agitation with Psychotic Features

Reserve antipsychotics only for severe agitation with psychotic features or aggression when SSRIs and behavioral approaches have failed: 4

• Risperidone (preferred): Start 0.25 mg once daily at bedtime, target dose 0.5-1.25 mg daily, maximum 2 mg/day (extrapyramidal symptoms increase above 2 mg/day) 4
• Haloperidol (for acute severe agitation): 0.5-1 mg orally or subcutaneously, maximum 5 mg daily in elderly patients 4
• Quetiapine (alternative): Start 12.5 mg twice daily, maximum 200 mg twice daily (more sedating, risk of orthostatic hypotension) 4

Critical Safety Discussion Required Before Antipsychotics

Before initiating any antipsychotic, discuss with the patient (if feasible) and surrogate decision maker: 4

• Increased mortality risk (1.6-1.7 times higher than placebo) in elderly dementia patients 4
• Cardiovascular effects including QT prolongation, sudden death, dysrhythmias, and hypotension 4
• Cerebrovascular adverse reactions (three-fold increase in stroke risk with risperidone and olanzapine) 4
• Falls risk, metabolic changes, and extrapyramidal symptoms 4

Dosing Strategy and Duration

• Use the lowest effective dose for the shortest possible duration 4
• Evaluate daily with in-person examination to assess ongoing need and side effects 4
• Attempt taper within 3-6 months to determine if still needed—approximately 47% of patients continue receiving antipsychotics after discharge without clear indication 4
• Monitor for extrapyramidal symptoms, falls, sedation, metabolic changes, QT prolongation, and cognitive worsening 4

What NOT to Use

Avoid benzodiazepines as first-line treatment for agitated delirium in elderly patients (except for alcohol or benzodiazepine withdrawal): 4

• Benzodiazepines increase delirium incidence and duration 4
• Cause paradoxical agitation in approximately 10% of elderly patients 4
• Risk respiratory depression, tolerance, addiction, and cognitive impairment 4

Avoid typical antipsychotics (haloperidol, fluphenazine, thiothixene) as first-line therapy due to 50% risk of tardive dyskinesia after 2 years of continuous use in elderly patients. 4

Monitoring and Reassessment

• Use ABC (antecedent-behavior-consequence) charting to systematically track agitation over several days and identify environmental triggers 4
• Repeat delirium screening regularly as mental status can fluctuate 2
• Review the need for medications at every visit and taper if no longer indicated 4
• Even with a positive response to SSRIs, periodically reassess the need for continued medication 4