ABPN Geriatric Psychiatry cheat sheet

Delirium is diagnosed by acute onset, fluctuating course, inattention, plus either disorganized thinking or altered level of consciousness; it is a medical emergency requiring cause identification.

Dementia prevalence roughly doubles every 5 years after age 65; Alzheimer disease accounts for 60-80% of cases, followed by vascular and Lewy body dementia.

Lewy body dementia features fluctuating cognition, visual hallucinations, parkinsonism, and REM sleep behavior disorder; neuroleptics can cause severe sensitivity reactions.

Frontotemporal dementia presents earlier (50s-60s) with behavioral disinhibition or language decline; memory is relatively spared early.

Depression is a reversible contributor to cognitive impairment ('pseudodementia'); late-life depression with new cognitive complaints warrants monitoring for progression to dementia.

Anticholinergic burden, benzodiazepines, and Z-drugs are the leading medication contributors to delirium and falls in older adults.

Normal-pressure hydrocephalus triad: gait apraxia, urinary incontinence, and cognitive decline; large-volume lumbar puncture may predict shunt response.

Vascular dementia shows stepwise decline with focal neurologic signs and imaging evidence of infarcts or white matter disease; risk factor control is the main intervention.

Elderly suicide risk is highest in older white men; atypical presentations include somatic complaints and less expressed suicidality, so screening is essential.

Major depressive disorder requires 5+ symptoms for 2 weeks including depressed mood or anhedonia; in older adults, somatic and cognitive symptoms often dominate.

Serotonin syndrome triad: mental status change, autonomic instability, and neuromuscular hyperactivity (clonus, hyperreflexia); onset is usually within 24 hours of serotonergic change.

Neuroleptic malignant syndrome: rigidity, hyperthermia, autonomic instability, elevated CK; onset over days, distinct from serotonin syndrome's clonus and rapid onset.

Tardive dyskinesia risk rises with age and duration of antipsychotic exposure; VMAT2 inhibitors (valbenazine, deutetrabenazine) are first-line treatments.

Benzodiazepine withdrawal can cause seizures and delirium; taper gradually, typically 25% dose reductions every 2 weeks.

SSRIs are first-line for late-life depression; hyponatremia (SIADH) risk is highest in the first weeks, especially with diuretics and low body weight.

QTc prolongation risk increases with age and polypharmacy; citalopram is limited to 20 mg/day in adults over 60 due to dose-dependent QT effects.

Lithium in older adults requires lower doses due to reduced renal clearance; tremor, confusion, and ataxia signal toxicity even at 'normal' levels.