Late-Life Depression & Behavioral Symptoms of Dementia
Treat the mood, find the trigger, spare the antipsychotic
Recognizing depression in older adults
Atypical presentation. Older adults often deny sadness and instead describe fatigue, pain, GI or other somatic complaints, apathy and loss of interest, insomnia, weight loss, and slowed thinking. Screening with the PHQ-9 or the Geriatric Depression Scale helps; the GDS uses simple yes/no items and fewer somatic questions, so physical illness inflates it less. New depression in late life can be a prodrome of dementia, so cognition should be followed over time.
Medical evaluation. Check TSH, B12, CBC, electrolytes, calcium, and glucose, and review drugs and alcohol (corticosteroids, interferon, benzodiazepines, opioids). Parkinson disease, stroke, and cancer commonly bring depression.
Suicide risk. Completed suicide rates peak in men aged 75 and older, classically older white men; by race and ethnicity, American Indian and Alaska Native people have the highest age-adjusted rates. Risk rises with widowhood, living alone, chronic pain or illness, alcohol use, and access to firearms, which are the most common method. Attempts in older adults are more lethal than in the young, and many people who die by suicide saw a primary care clinician in the preceding month. Always ask directly about suicidal thoughts, plans, and firearms, and restrict access to lethal means.
Depression versus dementia
Depression can impair attention, processing speed, and memory enough to mimic dementia, a picture traditionally called pseudodementia. The distinction matters because the cognitive deficits improve when the depression is treated.
| Feature | Depression (pseudodementia) | Dementia |
|---|---|---|
| Onset | Relatively rapid, often after a loss | Insidious |
| Sequence | Mood symptoms precede cognitive complaints | Cognitive decline precedes mood change |
| Patient's view | Emphasizes memory loss | Minimizes deficits or is unaware; family reports decline |
| Testing | "I don't know" answers, poor effort | Tries hard; near-miss answers, confabulation |
| Course | Improves with antidepressant treatment | Progressive |
Treating late-life depression
SSRIs first. Sertraline and escitalopram are first-line. Start low, titrate to a full therapeutic dose, and allow 8–12 weeks, since response can be slower than in younger adults. Continue for at least a year after remission (longer when episodes recur), and add psychotherapy such as CBT or problem-solving therapy when possible. Citalopram is capped at 20 mg/day after age 60 because of dose-dependent QT prolongation.
SSRI hazards. SSRIs can cause SIADH-related hyponatremia, so check sodium at baseline and within the first weeks, especially in patients taking thiazides. They also increase falls and hip fractures and raise GI bleeding risk when combined with NSAIDs, aspirin, or anticoagulants, for which a PPI can be added.
Mirtazapine. An α2 antagonist that also blocks 5-HT2, 5-HT3, and H1 receptors, mirtazapine sedates and stimulates appetite, making it well suited to depressed older adults with insomnia and weight loss. It causes little sexual dysfunction or GI upset but can cause weight gain, daytime sedation, and falls.
| Option | Best for | Cautions |
|---|---|---|
| Sertraline, escitalopram | First-line for most patients | Hyponatremia, falls, GI bleeding |
| Mirtazapine | Poor appetite, insomnia | Weight gain, sedation, falls |
| ECT | Psychotic depression, refusal to eat or drink, high suicide risk, catatonia, drug failure | Transient confusion and memory loss |
| TCAs (amitriptyline), paroxetine | Avoid (Beers) | Anticholinergic effects, orthostasis, arrhythmia, lethal overdose |
| Benzodiazepines, diphenhydramine, hydroxyzine, oxybutynin | Avoid (Beers) | Falls, fractures, delirium, urinary retention, constipation, cognitive decline |
Electroconvulsive therapy. ECT produces the highest response rates in late-life depression and works faster than medication. It is preferred for psychotic depression, refusal to eat or drink, high suicide risk, catatonia, and failure of or intolerance to antidepressants. The main adverse effects are transient confusion and memory loss. There are no absolute contraindications, but recent myocardial infarction or stroke and raised intracranial pressure require caution.
Behavioral and psychological symptoms of dementia
What they look like. Agitation, aggression, wandering, sundowning (evening worsening of confusion and restlessness), delusions of theft or infidelity, hallucinations, apathy, depression, and sleep disruption affect most people with dementia at some point and are a leading cause of caregiver burnout and nursing-home placement.
- Describe the behaviorWhat happens, when, where, and who is affected.
- Investigate triggersPain, constipation or impaction, urinary retention, UTI or pneumonia causing delirium, dehydration, hunger, sensory loss, and new drugs such as anticholinergics, benzodiazepines, and opioids.
- Nonpharmacologic planConsistent routine and caregiver, daytime activity and light exposure, bright evening lighting against sundowning, glasses and hearing aids, redirection rather than argument, less noise, secured exits and ID bracelets for wanderers, and caregiver training and support.
- Medication only for dangerLowest dose for the shortest time, with a clear target symptom and regular reassessment.
A sudden behavior change is often discomfort the patient cannot describe. Disimpaction, catheterization, or analgesia often ends the agitation, and scheduled acetaminophen for suspected pain can reduce agitation in nursing-home residents.
Medications for behavioral symptoms
Antipsychotics. They are justified only for severe agitation or psychosis that endangers the patient or others after other measures fail. Use the lowest dose for the shortest time, discuss risks with the patient or surrogate, and attempt a taper within about 4 months unless symptoms returned during a previous taper. Brexpiprazole is approved for agitation in Alzheimer dementia but carries the same warning.
The boxed warning covers typical and atypical antipsychotics alike: excess deaths are mostly cardiovascular (heart failure, sudden death) or infectious (pneumonia), and stroke risk is increased.
Dementia with Lewy bodies. These patients have severe neuroleptic sensitivity: typical and high-potency agents such as haloperidol can cause marked rigidity, confusion, falls, reactions resembling neuroleptic malignant syndrome, and death. Hallucinations are treated first with a cholinesterase inhibitor (rivastigmine or donepezil); if an antipsychotic is unavoidable, low-dose quetiapine or clozapine is used.
Alternatives. For persistent agitation without imminent danger, citalopram has trial evidence of reducing agitation in Alzheimer disease and avoids the antipsychotic mortality warning, but QTc must be monitored and geriatric dose limits respected. Benzodiazepines worsen confusion and falls and are avoided except for alcohol or benzodiazepine withdrawal. Anticholinergic sleep aids such as diphenhydramine are likewise avoided.