Psychosis, Hallucinations and Delusions in Dementia: What They Are, and What Actually Helps

This one describes hallucinations, paranoia and false beliefs in some detail, since understanding what's actually happening is part of what helps. If you're in the middle of a frightening episode right now, it might be worth coming back to this once things have settled.

This is more common than families expect

It's estimated that around half of people living with Alzheimer's dementia experience some form of psychosis, hallucinations, delusions, or both, at some point. It's common, genuinely under-discussed, and can be one of the most distressing parts of dementia to witness, particularly when it isn't a single passing episode but something that returns.

It's worth being clear about one distinction early on: this guide is about hallucinations and delusions as an ongoing feature of dementia itself. If confusion, hallucinations or a sudden personality change has come on suddenly, especially after a hospital stay, infection or new medication, that's more likely to be delirium, which is a different (and often reversible) thing, covered in our guide on sudden confusion and UTIs. If in doubt, any sudden, dramatic change is always worth an urgent medical check.

Hallucinations and delusions aren't the same thing

Hallucinations mean seeing, hearing, or sometimes feeling something that isn't actually there. Visual hallucinations are the most common, seeing a person, an animal, or a pattern that isn't real, and they're especially prevalent in Lewy body dementia (covered fully in our Lewy Body Dementia guide), where they can be vivid and detailed even early in the condition.

Delusions are strongly held false beliefs, not sensory experiences. The most common by far is a belief that something has been stolen, often directed at whoever is closest, a carer, a partner, an adult child. Other common delusions include believing a spouse is being unfaithful, that the house isn't really home, or, more rarely, that a familiar person has been replaced by an imposter.

Both can come with real fear and paranoia attached, believing you're being watched, that someone means you harm, or that people around you can't be trusted. That fear is genuinely real to the person experiencing it, even though the cause isn't.

Why this happens

These aren't a sign of "losing the mind" in some vague sense, they're driven by real changes in specific areas of the brain involved in perception, memory and reasoning. A delusion of theft, for example, is often the brain's way of making sense of memory loss: an item can't be found, so the mind fills the gap with an explanation, and "it was stolen" feels more coherent than "I've forgotten where I put it." Understanding this doesn't make it easier to live with, but it can help prevent the resentment that builds when a delusion aimed at you starts to feel personal. It isn't. The person isn't choosing to be suspicious of you any more than they're choosing to forget your name.

Certain things can make delusions and hallucinations more likely or worse: poorly corrected sight or hearing problems (Alzheimer's Society specifically recommends getting glasses and hearing aids checked), medication changes, and highly patterned or reflective surfaces, which can be genuinely misread by a changed visual system.

What genuinely helps, based on real clinical guidance

The instinct to correct or convince is completely understandable, but the guidance here is consistent and clear: don't argue, and don't try to prove someone wrong.

Don't correct, don't confront. Alzheimer's Society and multiple clinical sources agree: you generally won't be able to convince someone that a delusion is false, since it feels every bit as real to them as reality feels to you. Confronting it directly tends to increase distress rather than resolve anything.

Validate the feeling, not the false belief. Acknowledging the emotion behind what's happening, without agreeing to the content, and staying calm and warm, matters more than what you actually say. Something like "I'm sorry you're feeling scared, let's sit down together" does real work here.

Redirect gently, rather than dwell. Helping to look for a "missing" item, or shifting attention to a simple, calming task, is often more effective than any explanation. Clinicians describe this as genuinely powerful: staying engaged with the delusion itself tends to keep someone stuck in it.

Reduce likely triggers where you can. Regular medication reviews with a GP or pharmacist, good lighting, checking glasses and hearing aids are working properly, and keeping some regular social contact and activity in the routine can all genuinely reduce how often this happens.

Always flag it to a doctor, even if it feels manageable at home. This matters for two reasons: to rule out a treatable cause (a urine infection, a new medication, a sight or hearing problem), and because if medication is ever considered, there are real safety issues to be aware of, covered next.

A genuine safety warning on medication

If antipsychotic medication is ever suggested to manage hallucinations or delusions, it's worth knowing that this class of drug carries real risks in dementia, and particularly serious risks in Lewy body dementia specifically, where the wrong medication can cause a severe reaction. This is a conversation to have carefully and directly with a GP or specialist, not something to start or adjust without proper medical guidance either way.

Looking after yourself, not just the person you're caring for

Caring for someone experiencing ongoing psychosis is draining in a specific, quietly isolating way, different from the exhaustion of physical caregiving tasks. It's genuinely common for carers in this situation to experience higher stress, anxiety and lower wellbeing, and there's no need to wait until it becomes a crisis before reaching out. A GP, a carer support group, or simply naming what's happening to someone you trust are all reasonable places to start. Our You're Not Alone page has more on finding that kind of support.

A word from The Care Compass

If this is happening to someone you love, it's frightening, and it's alright to find it frightening even once you understand what's behind it. Knowing the "why" doesn't erase the fear in the moment, for either of you, but it can help take some of the personal sting out of it, and give you something concrete to try, rather than just bracing for the next episode.

This article is for general guidance only and does not constitute medical advice. If someone's behaviour changes suddenly and dramatically, or you're concerned for anyone's safety, contact 999 in an emergency, or 111 for urgent but non-emergency concerns.

You don’t have to navigate it alone.