Mr. J, an 81-year-old retired engineer, is admitted for pneumonia. On day two, he pulls out his IV, accuses staff of poisoning him, and tries to climb out of bed. Psychiatry is consulted. His wife says that he has been slower and a little forgetful for months, but has never demonstrated behavior like this. She asks, “When will he be back to normal?”

Altered mental status is one of the most common reasons medical teams call consultation-liaison psychiatry. In older inpatients, the question is often framed as delirium versus dementia. But often, the answer is both. Our job is to help the team sort out what is new, what was already brewing, and what can be treated now.

A useful way to think about the situation is “baseline vulnerability plus acute stressor.” A patient may have subtle cognitive decline and still function reasonably well at home—until that compensation is overwhelmed by pneumonia, surgery, dehydration, pain, sleep deprivation, or a new medication. Baseline vulnerabilities include older age, underlying cognitive impairment, sensory deficits, poor functional status, and heavy medical burden. The more vulnerable the brain, the less it takes to push the patient into delirium (Oldham MA et al, J Neuropsychiatry Clin Neurosci 2018;30(1):51–57).

We are often called for the dramatic presentations: acute paranoia, agitation, pulling at lines, trying to elope. But quieter cases are just as important. Hypoactive delirium is easy to miss because the patient may look sleepy, depressed, or simply “not engaged.” Whether hyperactive or hypoactive, delirium is not benign. It’s associated with increased mortality, longer hospital stays, and accelerated long-term cognitive decline (Oldham et al, 2018).

Differentiating delirium from dementia
The clinical interview is still the cornerstone of diagnosis. But patients with acute confusion often cannot give reliable histories, so collateral is not optional. Call the family or caregiver early.

From the article: “Delirium Versus Dementia in the Medical Inpatient Setting” by Jose A. Ribas Roca, MD, and Carolyn TK Tran, PhD, DNP, APRN, GNP-BC, PMHNP-BC. The Carlat Hospital Psychiatry Report, Volume 6, Number 5&6, July/August/September 2026. www.thecarlatreport.com

Download Table as PDF.

Start with the time course. Delirium usually develops over hours to days. Dementia unfolds over months to years. Ask when the patient was last clearly at baseline and what the earliest signs of decline looked like. Families may give vague answers at first, like, “He’s been off for a while.” Ask for concrete examples: Was he managing medications, bills, appointments, driving, or cooking? These questions often tell you more than any formal cognitive test.

Fluctuation is another major clue. Delirium waxes and wanes, sometimes dramatically, over the course of a day. Staff may describe a patient who is lucid in the morning, confused by noon, and somnolent by evening. Dementia tends to be steadier, with a gradual decline rather than abrupt swings in attention or arousal.

Attention is particularly helpful diagnostically. Even patients with moderate dementia can often sustain attention reasonably well early in the illness, whereas a delirious patient struggles to track conversation, follow simple commands, or maintain a coherent line of thought. Arousal matters too. Hypervigilance, lethargy, drowsiness, and waxing alertness all point toward delirium.

Ask about prior episodes. Recurrent delirium during previous hospitalizations, especially episodes requiring sedating medications or sitters, suggests underlying cognitive vulnerability (see “How to Distinguish the Dementias” in CGPR Jan/Feb/Mar 2022). And check the medical record. Prior cognitive screening, neurology notes, and skilled nursing documentation can help reconstruct the patient’s true baseline.

Look closely at attention
At the bedside, start simple. Ask, “Why are you in the hospital? What happened before you came in?” These questions quickly show whether the patient can relate a coherent narrative and retain recently learned information.

Then try a basic attention task. Ask the patient to spell “world” backward or say the months of the year in reverse. These are low-tech, fast, and often very revealing. For formal delirium screening, the Confusion Assessment Method (CAM) remains the best-known bedside tool (Inouye SK et al, Ann Intern Med 1990;113(12):941–948). It is free, practical, and only takes a few minutes. A printable version of the CAM instrument is available here: www.tinyurl.com/y8s3aytm. We use the CAM less as a formal test and more as a framework to document acute change, fluctuation, inattention, disorganized thinking, and altered arousal. For nonverbal or ventilated ICU patients, use the CAM-ICU instead (www.tinyurl.com/4warze6n).

Be cautious with the MoCA and MMSE during acute illness. Pain, fatigue, infection, sleep deprivation, medications, and delirium itself can all lower the scores on these tests; a patient may present quite differently once the acute illness clears. If dementia remains a concern, reassess later.

Don’t miss hypoactive delirium
Hypoactive delirium is easy to overlook because patients are quiet rather than disruptive. They may seem sleepy, apathetic, disengaged, unmotivated, or depressed. But once you recognize delirium, the question changes from, “Why isn’t this patient trying?” to “What medical problem is driving this?” Sometimes psychiatry’s most useful intervention is simply naming what is happening.

When delirium unmasks dementia
Delirium often brings preexisting cognitive problems into view. Families may say, “She was fine before this,” but further questioning can reveal a patient who has been repeating herself, mismanaging medications, or relying more heavily on a spouse for months.

Many patients compensate for early neurocognitive decline surprisingly well in familiar settings. Acute illness overwhelms that cognitive reserve, resulting in a patient who looks dramatically worse in the hospital than anyone expected.

This is where expectation-setting matters. Delirium may improve over days to weeks, but full recovery is not guaranteed. In frail patients and in those with preexisting cognitive impairment, the hospitalization may reveal a new baseline rather than a temporary detour. Delirium is also associated with worse long-term cognitive outcomes, which is one more reason to identify it early (Oldham et al, 2018).

When dementia is still on the table, ask the family what changed first. Memory? Language? Judgment? Executive function? Personality? Independence? Those details help distinguish mild from major neurocognitive disorder and may point toward a dementia subtype (Sachdev P et al, Nat Rev Neurol 2014;10:634–642).

Managing symptoms and supporting the family

Help the team look for the trigger
Delirium is a medical syndrome first. Psychiatry usually does not “own” the medical workup, but we can help the team stay focused on reversible contributors. Start with the medication list: Anticholinergics, benzodiazepines, opioids, steroids, sedative-hypnotics, polypharmacy, and recent medication changes are common culprits.

Then make targeted recommendations rather than asking for a generic “delirium workup.” First look for common acute precipitants, such as infection, hypoxia, dehydration, untreated pain, constipation, withdrawal, metabolic derangement, sleep disruption, and medication effects. Recommendations might include, “Review need for diphenhydramine and benzodiazepines” or “Consider whether pain or constipation is driving agitation.” If cognitive changes may have preceded admission, also check whether the team has considered reversible contributors to cognitive impairment, such as thyroid disease, B12 or folate deficiency, and other metabolic causes.

Nonpharmacologic measures
Before reaching for medications, make delirium precautions practical by assigning them to the people who can actually carry them out. In your note and verbal recommendations, tell nursing what to prioritize at the bedside: Keep glasses and hearing aids in place, reorient the patient calmly, avoid arguing with delusions, reduce nighttime disruptions as much as safely possible, maintain day-night cues, and use a sitter when the patient needs reassurance or is pulling at lines or trying to get out of bed. If the patient is deconditioned or immobilized, recommend PT/OT involvement for safe mobilization. Families can also help, but give specific instructions: Bring familiar objects, stay during high-risk evening hours if possible, and reassure the patient without debating their delusions.

Medications and restraints
Ideally, we would use medications only when symptoms create a safety risk or prevent necessary medical care. But by the time psychiatry is called, many patients have already received haloperidol, quetiapine, lorazepam, or some combination. Start by reviewing what was given, the target symptom, and the response. If the family says, “He got worse after that medication,” pay attention. While benzodiazepines are effective for alcohol or sedative-hypnotic withdrawal, in other cases they can worsen delirium by increasing confusion, disinhibition, oversedation, respiratory suppression, aspiration risk, and falls. Antipsychotics also carry risks in older adults, including sedation, orthostasis, falls, EPS/akathisia, QT prolongation, and increased mortality in patients with dementia-related psychosis.

The point is not to never use medications, but rather to use the lowest effective dose for a clearly documented target symptom, reassess daily, and stop as soon as possible.

Note: These are starting-dose ranges, not standing regimens. Document the target symptom, reassess daily, and stop the medication as soon as the safety risk or interference with medical care resolves.

From the article: “Delirium Versus Dementia in the Medical Inpatient Setting” by Jose A. Ribas Roca, MD, and Carolyn TK Tran, PhD, DNP, APRN, GNP-BC, PMHNP-BC. The Carlat Hospital Psychiatry Report, Volume 6, Number 5&6, July/August/September 2026. www.thecarlatreport.com

Download this Table as a PDF.

For patients who are frightened, paranoid, pulling out lines, and trying to climb out of bed, first decide what risk you need to address. If fear-driven agitation or paranoia is making them unsafe and they can take oral medication, consider low-dose haloperidol 0.5–1 mg PO or olanzapine 2.5–5 mg PO/ODT. If the patient cannot take oral medication and poses an imminent safety risk, you may need to order IM medication. For repeat or scheduled dosing, review the available ECG, electrolytes, interacting medications, oversedation risk, and Parkinson’s disease/Lewy body dementia risk.

Match the restraint, if needed, to the specific danger. If the patient keeps pulling at essential IVs, oxygen tubing, feeding tubes, or other medical equipment despite redirection, consider temporary soft mitts or soft wrist restraints. If they repeatedly try to climb out of bed despite redirection, sitter support, and environmental changes, a vest restraint may sometimes make sense. Use restraints only as a temporary safety intervention, not as treatment for delirium. Because restraints can worsen fear and agitation, document the specific danger, what less-restrictive measures you tried, how staff will monitor the patient, and when you will reassess for removal.

Avoid haloperidol in patients with Parkinson’s disease or suspected Lewy body dementia; in these patients, low-dose quetiapine, such as 12.5–25 mg PO, is often safer but slower. Quetiapine 12.5–25 mg at bedtime can also be helpful when sleep-wake reversal is prominent and the patient can take oral medication, but it is not the best choice when the immediate problem is dangerous agitation. Ramelteon 8 mg at bedtime is sometimes used to support sleep-wake regulation in high-risk patients and might even help prevent delirium (Hatta K et al, JAMA Psychiatry 2014;71(4):397–403). Avoid lorazepam unless you are treating alcohol or sedative-hypnotic withdrawal, suspected catatonia, or seizure-related agitation.

Whatever you prescribe, document the target symptom: “for severe agitation interfering with pneumonia treatment,” not “for dementia” or “for psychosis.” If the patient is discharged on an antipsychotic started for delirium, include a reassessment and discontinuation plan. Otherwise, a short-term hospital medication can quietly become a long-term outpatient medication.

Prognosis and discharge planning
Help families know what to watch for after discharge. Recovery may be gradual, and worsening confusion, sleep-wake reversal, poor intake, or new agitation should prompt a call to the patient’s primary physician or outpatient psychiatrist. Make sure there is a clear plan to reassess cognition, review medications, and decide whether the patient can safely return home or needs more support, such as home health, skilled nursing, or memory care.

The medical team moves Mr. J closer to the nursing station, his wife stays at the bedside in the evening, and staff make sure he has his glasses and hearing aids. Psychiatry recommends stopping diphenhydramine, minimizing nighttime disruptions, treating pain, monitoring oxygenation, and checking for urinary retention and constipation. Because he remains frightened and unsafe—pulling at IVs and trying to elope—he receives haloperidol 0.5 mg once, with a plan to repeat only for recurrent severe agitation after reassessment and failed nonpharmacologic measures. He does not need ongoing scheduled antipsychotics.

Over the next few days, Mr. J’s pneumonia improves, delirium precautions continue, and he becomes calmer and reengaged with his wife. The team explains that the acute episode was delirium, but that months of subtle decline beforehand may have highlighted an underlying neurocognitive disorder. By discharge, the delirium has largely cleared, the antipsychotic is stopped, and his wife leaves with a clearer picture of what to watch for next.

Carlat Verdict: In older hospitalized patients with altered mental status, assume delirium and dementia overlap until collateral history clarifies what is acute versus chronic. Watch for hypoactive delirium, which can masquerade as depression, apathy, or “poor effort,” and don’t overinterpret cognitive testing during acute illness. Psychiatry can help identify precipitants, reduce deliriogenic medications, calm unsafe agitation, and guide families through uncertainty. Reserve medications for dangerous symptoms or behaviors that interfere with medical care, and make a clear plan to stop meds once started.