Neurocognitive disorders (NCDs) are acquired declines in cognition from a previous level of functioning. DSM-5-TR groups them into three categories: delirium, mild neurocognitive disorder, and major neurocognitive disorder (the term that largely replaces "dementia," although dementia is still used clinically).
Cognitive domains: complex attention, executive function, learning and memory, language, perceptual-motor function, and social cognition.
Major vs. mild NCD
| Feature | Mild NCD | Major NCD |
|---|
| Decline from previous level | Modest, noticed by the person, family, or clinician | Significant decline from previous performance |
| Test performance | Typically 1–2 standard deviations below norms | Typically 2 or more standard deviations below norms |
| Daily function | Independent, though tasks take more effort or compensation | Interferes with independence in everyday activities (bills, medications) |
Mild cognitive impairment (MCI) corresponds to mild NCD and is seen as an intermediate stage between normal aging and dementia; some people remain stable or improve, while a proportion progress each year.
Both require that the deficits do not occur only during delirium and are not better explained by another mental disorder (such as depression).
Delirium vs. dementia vs. depression
| Feature | Delirium | Dementia (major NCD) | Depression ("pseudodementia") |
|---|
| Onset | Acute — hours to days | Insidious — months to years | Relatively rapid, often linked to a loss |
| Course | Fluctuates, often worse at night | Slowly progressive | Worse in the morning |
| Attention and consciousness | Impaired attention, altered level of consciousness | Alert; attention intact until late | Normal |
| Cause | Underlying medical condition, drug, or withdrawal | Neurodegeneration or vascular disease | Mood disorder |
| Reversibility | Usually reversible when the cause is treated | Mostly irreversible | Improves with treatment |
| Typical response to testing | Cannot focus | Tries, confabulates, covers deficits | "I don't know," little effort |
Delirium is a medical emergency: it raises mortality, length of stay, and later cognitive decline. Common causes: infection (urinary, pneumonia), drugs (anticholinergics, benzodiazepines, opioids), withdrawal, hypoxia, dehydration, electrolyte and glucose disturbances, urinary retention, constipation, pain, and surgery. People with dementia are at highest risk (delirium superimposed on dementia).
Subtypes of major and mild NCD
| Subtype | Key features |
|---|
| Alzheimer disease | Most common. Amyloid-beta plaques, tau tangles, cholinergic loss. Gradual onset; recent memory lost first, then language (aphasia), praxis (apraxia), recognition (agnosia), and executive function |
| Vascular | Stepwise or abrupt decline linked to stroke or transient ischemic attack; risk factors hypertension, diabetes, smoking, atrial fibrillation, hyperlipidemia |
| Lewy body | Fluctuating cognition, recurrent vivid visual hallucinations, parkinsonism, REM sleep behavior disorder; severe sensitivity to antipsychotics |
| Frontotemporal | Earlier onset (often 45–65); early personality and social behavior change, disinhibition, apathy, impulsivity, or language decline; memory relatively preserved early |
| Parkinson disease, Huntington disease, traumatic brain injury, HIV, prion disease, substance/medication-induced (e.g., alcohol-related Korsakoff syndrome) | Diagnosed by the underlying condition |
Neuropsychiatric symptoms in NCD include apathy, depression, anxiety, agitation, delusions (often of theft), hallucinations, wandering, sundowning, and sleep disturbance.
- Onset and course from family or caregivers — the most important distinction between delirium and dementia
- Level of consciousness and attention (e.g., months of the year backward)
- Orientation, memory, language, judgment, safety awareness
- Functional status: activities of daily living and instrumental activities
- Behavioral symptoms, depression screening, pain (use observational scales such as PAINAD in advanced dementia)
- Delirium subtypes: hyperactive (agitation, pulling lines), hypoactive (quiet, drowsy, withdrawn — most often missed), mixed
- Medication review for anticholinergic and sedating drugs
- Safety: falls, wandering, driving, stove, firearms, financial exploitation, caregiver strain
| Tool/test | Use |
|---|
| Confusion Assessment Method (CAM / CAM-ICU) | Delirium: acute onset and fluctuating course plus inattention plus either disorganized thinking or altered level of consciousness |
| 4AT | Brief delirium screen |
| Mini-Cog | 3-word recall plus clock drawing; rapid screen |
| Montreal Cognitive Assessment (MoCA) | More sensitive than the MMSE for MCI and executive dysfunction; score out of 30 |
| Mini-Mental State Examination (MMSE) | Score out of 30; lower scores indicate more impairment; affected by education and language |
| Labs to find reversible causes | CBC, electrolytes, glucose, kidney and liver function, vitamin B12, thyroid function, urinalysis; syphilis or HIV when indicated |
| Neuroimaging (CT/MRI) | Stroke, tumor, subdural hematoma, normal pressure hydrocephalus, atrophy pattern |
| Amyloid PET, CSF biomarkers, or validated blood biomarkers | Confirm Alzheimer pathology — required before anti-amyloid therapy |
Delirium
- Find and treat the cause — this is the definitive treatment
- Nonpharmacologic multicomponent prevention and care are first-line
- Antipsychotics are not recommended routinely; low doses may be used short term only for severe distress or danger. Avoid benzodiazepines except for alcohol or benzodiazepine withdrawal
- Stop or reduce deliriogenic drugs (anticholinergics, sedative-hypnotics, some opioids)
Alzheimer disease and related dementias (consistent with the Medical-Surgical degenerative neurologic topic)
- Cholinesterase inhibitors (donepezil, rivastigmine, galantamine): modest symptomatic benefit across stages. Adverse effects: nausea, diarrhea, weight loss, bradycardia and syncope, vivid dreams (give donepezil in the morning if this occurs). Caution with conduction disease and with beta blockers; increased GI bleeding risk with NSAIDs. Rivastigmine patch: rotate sites, remove the old patch
- Memantine: NMDA receptor antagonist for moderate to severe Alzheimer disease; dizziness, headache, confusion, constipation; reduce dose in kidney impairment
- Anti-amyloid monoclonal antibodies (lecanemab, donanemab): for early Alzheimer disease (MCI or mild dementia) with confirmed amyloid; given by IV infusion (lecanemab is also available as a subcutaneous autoinjector); they modestly slow decline. Boxed warning for amyloid-related imaging abnormalities (ARIA) — brain edema or microhemorrhage — so scheduled MRI monitoring is required; highest risk in APOE e4 homozygotes; caution with anticoagulants. ARIA can mimic stroke, so clients carry a treatment card and thrombolysis needs extra caution
- Vascular NCD: control blood pressure, diabetes, lipids; antiplatelet or anticoagulant therapy as indicated; smoking cessation
- Behavioral symptoms: nonpharmacologic approaches first. All antipsychotics carry a boxed warning for increased mortality in older adults with dementia-related psychosis; use only for severe distress or danger, at the lowest dose, with regular reassessment. Avoid haloperidol and other dopamine blockers in Lewy body dementia.
- Avoid strongly anticholinergic drugs (e.g., diphenhydramine, oxybutynin, tricyclic antidepressants) and benzodiazepines in older adults
Listed in priority order.
- Physiologic stability and cause (delirium) — vital signs, oxygenation, hydration, glucose, bowel and bladder status, pain, infection signs; report acute confusion promptly as a change in condition
- Safety and fall prevention
- Low bed, call light in reach, nonslip footwear, night lights, clutter-free room, scheduled toileting
- Do not keep all bed rails up to restrict movement — it increases injury from climbing over rails; avoid physical restraints
- Bed or chair alarms, frequent rounding, sitter if needed; wander-management systems and identification bracelets
- Reorientation and environment
- Clocks, calendars, natural light by day, dark and quiet at night; glasses and hearing aids in place
- Consistent caregivers; family presence
- Early mobilization; normal sleep–wake cycle
- Communication
- Face the client, call by name, speak slowly in short, simple sentences, one step at a time; use visual cues
- For delusions (e.g., "The nurse stole my wallet"): respond to the feeling, do not argue, and redirect — "Losing your wallet is upsetting. Let's look for it together."
- Validation and reminiscence rather than confrontation in moderate to severe dementia; reality orientation is useful mainly in delirium and mild impairment
- Structured routine — consistent daily schedule; avoid complex decisions and overstimulation; break tasks into simple steps; allow time
- Sundowning — daytime activity and light exposure, limit daytime napping, reduce evening noise and caffeine, calm evening routine
- Nutrition and self-care — finger foods, supervision, weight monitoring, swallowing assessment, oral care
- Caregiver support — assess strain; teach, plan respite, connect with support groups
- Family: report any sudden change in thinking or behavior — it may be delirium from infection or medication
- Keep a regular routine; use calendars, pill organizers, and labeled doors
- Home safety: secure medications, knives, car keys, stove knobs, and firearms; remove trip hazards; install locks or alarms on exits
- Plan early for legal and financial decisions (advance directive, health care proxy) while the client can participate
- Cholinesterase inhibitors: take with food; report fainting, slow pulse, black stools, or weight loss
- Anti-amyloid therapy: keep all MRI appointments; report headache, confusion, vision change, or seizures; carry a treatment card
- Brain health and vascular risk reduction: control blood pressure, diabetes, and cholesterol; regular aerobic exercise; stop smoking; limit alcohol; treat hearing loss; stay socially and mentally active
- Caregivers: plan rest and personal time, accept help, and use respite services to prevent burnout
| Complication | What to watch for |
|---|
| Delirium (including superimposed on dementia) | Sudden confusion, inattention, fluctuating alertness, new agitation or drowsiness |
| Falls and hip fracture | Unsteady gait, getting up alone at night |
| Wandering and elopement | Exit seeking, restlessness |
| Aspiration pneumonia | Coughing with meals, fever, crackles — common cause of death in advanced dementia |
| Malnutrition and dehydration | Weight loss, poor intake |
| Elder abuse, neglect, or financial exploitation | Unexplained injuries, fearfulness, missing money |
| Caregiver burnout | Exhaustion, depression, anger toward the client |
| ARIA with anti-amyloid therapy | Headache, confusion, vision change, seizures |
- Delirium = acute, fluctuating, inattention, usually reversible; dementia = insidious, progressive, alert
- Hypoactive delirium is the most often missed type; screen with CAM
- Delirium treatment = treat the cause; avoid benzodiazepines and anticholinergics
- Major NCD requires significant decline from previous level that interferes with independence
- MCI = intermediate stage between normal aging and dementia; MoCA detects it better than MMSE
- Frontotemporal → early personality and social behavior change
- Lewy body → vivid visual hallucinations + parkinsonism; avoid antipsychotics like haloperidol
- Vascular → history of stroke/TIA; prevent with blood pressure control and exercise
- Memantine = NMDA antagonist; cholinesterase inhibitors → bradycardia
- Accusations of theft: acknowledge feelings, do not argue, help search
- Consistent routine; no routine full bed rails or restraints
Country Notes
United States
- Lecanemab and donanemab are FDA-approved for early Alzheimer disease; Medicare coverage has required clinician participation in a CMS registry (check current rules).
- The Beers Criteria (American Geriatrics Society) guide avoidance of anticholinergic drugs and benzodiazepines in older adults.
Philippines
- Family members, often adult children, usually provide home care; caregiver teaching and respite planning are central nursing tasks.
- Cognitive screening tools should be used in a validated Filipino or local-language version where available, and interpreted with education level in mind.