Behavioral & Psychiatric Features
Behavioral & Psychiatric Features
What You'll Learn
- Neuropsychiatric symptoms (NPS) affect >90% of dementia patients and are the strongest drivers of caregiver burden, earlier institutionalization, and faster cognitive decline
- Behavioral profile varies by dementia type: apathy dominates AD; visual hallucinations define DLB; disinhibition/loss of empathy characterize bvFTD; depression/emotional incontinence in VaD
- DICE framework (Describe, Investigate, Create plan, Evaluate) — non-pharmacological interventions are first-line for agitation/aggression
- FDA black box warning: all antipsychotics carry 1.6–1.7× increased mortality risk in elderly dementia patients (cerebrovascular events, infections, sudden death)
- Brexpiprazole (2023) — first FDA-approved medication for agitation in Alzheimer disease
- Apathy ≠ depression: apathy = absence of motivation WITHOUT sadness; depression = sadness + hopelessness — treatment differs substantially
- Capacity assessment is decision-specific, not global — a patient may retain capacity for some decisions but not others
HighYield Pearls
- Neuroleptic sensitivity in DLB: haloperidol & typical antipsychotics can trigger fatal NMS-like reaction — AVOID; use low-dose quetiapine or pimavanserin if antipsychotic essential
- Black box warning: ALL antipsychotics carry 1.6–1.7× mortality risk in elderly dementia (cerebrovascular events, infection, sudden death) — document risk-benefit discussion
- Brexpiprazole (Rexulti): FIRST & ONLY FDA-approved agent for agitation in AD (2023); still carries black box warning
- Pimavanserin (Nuplazid): selective 5HT2A inverse agonist, NO D2 blockade — FDA-approved for PD psychosis; used off-label in DLB
- Citalopram cap ≤20 mg in elderly (QT prolongation); CITAD trial — modest benefit for agitation in AD
- Apathy ≠ depression: apathy = loss of motivation WITHOUT sadness/hopelessness — SSRIs don’t help apathy; consider methylphenidate
- RBD in DLB/PDD: secure the sleep environment. AASM 2023 conditionally recommends immediate-release melatonin, clonazepam, and rivastigmine for secondary RBD — IR melatonin is often preferred initially in dementia because of safety; clonazepam is also guideline-supported but requires caution for falls, delirium, and OSA
- bvFTD pharmacology pitfalls: AVOID cholinesterase inhibitors (worsen behavior) and antipsychotics (tau-related neuroleptic sensitivity); use SSRI (citalopram, sertraline) or trazodone
- Non-pharmacologic FIRST-LINE: DICE framework (Describe-Investigate-Create-Evaluate) — always screen for pain (PAIN-AD), UTI, constipation, medication side effects before escalating
- Feeding tubes in advanced dementia: NO mortality benefit, increased aspiration & pressure ulcers — recommend comfort feeding (AGS Choosing Wisely)
🔍 Quick ReferenceSymptom / phenotype · Etiology / dementia subtype · Treatment
Symptom / phenotype
- Well-formed visual hallucinations (people, animals, children) → DLB core feature
- Capgras syndrome (familiar person replaced by imposter) + mirror sign + phantom boarder → AD / DLB delusional misidentification
- Delusion of theft / infidelity → Alzheimer disease (most common delusional type)
- Late-afternoon agitation, confusion, wandering → Sundowning (AD)
- Disinhibition + hyperorality (carbohydrate craving) + loss of empathy + perseveration → bvFTD
- Involuntary crying/laughing disproportionate to mood → Pseudobulbar affect (VaD, ALS, MS)
- Dream enactment behavior, kicking/punching during sleep → REM sleep behavior disorder (DLB / synucleinopathy prodrome)
- Apathy without sadness, “just doesn’t care” → Most common NPS across all dementias (esp. AD, bvFTD)
Etiology / dementia subtype
- Severe neuroleptic sensitivity → NMS-like reaction after low-dose haloperidol → DLB
- Behavioral changes precede memory loss by years; reckless spending, inappropriate sexual comments → bvFTD
- Depression + executive dysfunction + emotional incontinence + stepwise decline → Vascular dementia
- Apathy + theft delusions + sundowning + late-stage agitation → Alzheimer disease
- Visual hallucinations + RBD + fluctuating cognition + parkinsonism → DLB core tetrad
- Hypersexuality, hyperphagia, hyperorality, placidity → Klüver-Bucy syndrome (advanced bvFTD, HSV encephalitis sequela)
Treatment / pearls
- Brexpiprazole (Rexulti) → FDA-approved (2023) for agitation in AD — first & only
- Pimavanserin (Nuplazid) → PD psychosis; 5HT2A inverse agonist, no D2 block; off-label DLB
- Citalopram ≤20 mg/day → Agitation in AD (CITAD trial); QT cap in elderly
- Quetiapine low-dose → Preferred antipsychotic in DLB if essential (least D2 affinity)
- Immediate-release melatonin → RBD: AASM 2023 conditional recommendation, often preferred initially in dementia for safety (clonazepam & rivastigmine also guideline-supported); sundowning adjunct
- Dextromethorphan/quinidine (Nuedexta) → Pseudobulbar affect in VaD/ALS/MS
- DICE framework + caregiver education + structured routine → First-line for agitation/aggression
- AVOID: haloperidol (DLB), benzodiazepines (falls/delirium), TCAs (anticholinergic), cholinesterase inhibitors in bvFTD, feeding tubes in late dementia → Beers/AGS Choosing Wisely
Neuropsychiatric Symptoms — Overview
Epidemiology & Impact
- NPS prevalence: >90% of dementia patients experience ≥1 NPS during illness course
- Most common across all dementias: apathy (49–72%), followed by depression (20–50%), agitation (30–50%)
- NPS are associated with: faster cognitive decline, earlier nursing home placement, increased mortality, greater caregiver burden and depression
- NPS account for more caregiver distress than cognitive symptoms themselves
- Cost of NPS management — estimated 30% of total dementia care costs
Assessment Tools
| Tool | Domains | Informant | Use |
|---|---|---|---|
| NPI (Neuropsychiatric Inventory) | 12 domains (delusions, hallucinations, agitation, depression, anxiety, euphoria, apathy, disinhibition, irritability, aberrant motor, sleep, appetite) | Caregiver | Gold standard for NPS assessment in dementia research and clinical trials |
| NPI-Q (Questionnaire) | Same 12 domains | Caregiver self-report | Briefer screening version for clinical use |
| Cohen-Mansfield Agitation Inventory (CMAI) | 29 agitation behaviors | Nursing staff | Nursing home settings; tracks agitation frequency |
| Cornell Scale for Depression in Dementia (CSDD) | 19 depression items | Clinician + caregiver | Validated for depression assessment in dementia (unlike GDS/PHQ-9) |
💎 Board Pearl
- The NPI is the standard tool for assessing NPS in dementia — covers 12 behavioral domains scored by frequency × severity; the Cornell Scale is the validated depression instrument for patients with dementia
- Always evaluate NPS before attributing behavior to dementia progression — delirium (UTI, medication changes, pain, constipation) is the most common reversible mimicker
Behavioral Symptoms by Dementia Type
Characteristic NPS Profiles
| Dementia Type | Most Common NPS | Characteristic Features | Board-Relevant Details |
|---|---|---|---|
| Alzheimer Disease (AD) | Apathy (most common), depression, anxiety | Agitation/aggression (later stages); delusions (theft, infidelity); wandering; sundowning | Apathy increases with disease severity; delusions of theft are most common delusional type; sundowning = increased confusion/agitation in late afternoon/evening |
| Dementia with Lewy Bodies (DLB) | Visual hallucinations (core feature), depression | REM sleep behavior disorder (RBD); well-formed visual hallucinations (people, animals); paranoid delusions; anxiety; Capgras syndrome | Visual hallucinations are a core diagnostic criterion; recurrent, detailed, well-formed; severe neuroleptic sensitivity — antipsychotics can be fatal |
| bvFTD | Apathy/inertia, disinhibition | Loss of empathy/sympathy; compulsive/ritualistic behaviors; hyperorality (dietary changes, carbohydrate craving); loss of social awareness | Behavioral changes precede memory loss by years; disinhibition includes inappropriate sexual behavior, reckless spending; often misdiagnosed as psychiatric illness |
| Vascular Dementia (VaD) | Depression, apathy | Psychomotor slowing; emotional incontinence (pseudobulbar affect); personality changes; executive dysfunction → behavioral dysregulation | Depression may precede or accompany VaD; emotional incontinence = involuntary crying/laughing disproportionate to mood — treat with dextromethorphan/quinidine (Nuedexta) |
Hallucination Characteristics by Dementia Type
| Feature | DLB | AD | Parkinson Disease Dementia |
|---|---|---|---|
| Modality | Visual >> auditory | Visual > auditory (late stages) | Visual (similar to DLB) |
| Content | Well-formed people, children, animals | Less formed; often paranoid/persecutory | Well-formed people, animals |
| Timing | Early, recurrent (core feature) | Usually moderate-to-severe stages | Fluctuating; often medication-related |
| Insight | May retain partial insight early | Poor insight | May retain partial insight |
| Mechanism | Cholinergic deficit + visual cortex Lewy bodies | Cholinergic deficit + cortical atrophy | Cholinergic deficit + dopaminergic therapy |
💎 Board Pearl
- Well-formed, recurrent visual hallucinations (people, children, animals) early in disease = think DLB until proven otherwise — this is a core diagnostic criterion
- bvFTD behavioral changes precede memory loss — patients are frequently misdiagnosed with depression, bipolar disorder, or personality disorder for years before correct diagnosis
- Neuroleptic sensitivity in DLB: antipsychotics can cause severe/fatal parkinsonism, rigidity, obtundation — avoid typical antipsychotics entirely. Pimavanserin is FDA-approved for PD psychosis only; off-label in DLB; per 2017 DLB consensus, low-dose quetiapine or clozapine are preferred when antipsychotic is absolutely needed
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