In fact, a study published in 2015 in the journal Movement Disorders suggests that some people might experience hallucinations early on in the disease, even before motor symptoms, such as tremors, manifest. While symptoms may vary from person to person, there are some clues that your loved one may be experiencing Parkinson’s related psychosis. And these symptoms can last anywhere from a few seconds to nearly all day. Here’s what to look out for:

1. They mistake objects for people or animals.

The most common symptoms of Parkinson’s related psychosis are visual illusions and hallucinations, says Dr. Barrett. These can start out mild, with the person looking at an object but seeing something else. For example, they might mistake a lamp for a human or think the mailbox is a deer. “These are early, minor hallucinations that may evolve to be more bothersome or pervasive,” says Barrett.

2. They sense a presence that isn’t there.

These passive hallucinations are visual hallucinations, even though your loved one might not actually “see” anything. “They might sense that there is a person standing behind them, looking over their shoulder, or that there are people in their house that are not actually there,” he says.

3. They conjure images.

This is a more severe type of visual hallucination that happens when a person sees something, often a person or animal, when in fact there is no one or nothing there at all, says Barrett. Some people are bothered by these images; some are not.

4. They hear noises or voices that aren’t there.

People with Parkinson’s related psychosis commonly report hearing footsteps, a shutting door, or creaking in the house that others don’t hear, says Barrett. These auditory hallucinations are less common than visual hallucinations, but sometimes they occur in tandem, especially in those with more severe psychosis.

5. They feel something crawling on them.

Known as tactile hallucinations, these are not as common as the visual or auditory types, but they can be vivid. For example, some people report that they feel a snake or dog crawling on them under their sheets in bed, says Barrett.

6. They experience delusions.

Delusions are false, fixed beliefs that do not subside even when there’s evidence to the contrary. For example, a person might say that their adult children are living in their house, when in fact their offspring live in other states, says Barrett.

7. They are fearful.

Your loved one might worry that someone is trying to break into their house or steal their money, and they might try to avoid (or fight) the perceived threat. These paranoid hallucinations, paired with delusions, can result in fear. “They believe they are truly in danger,” says Barrett. “It’s almost a normal reaction, because that belief is felt so strongly.”

8. They are agitated, irritable, or accusatory.

Paranoid hallucinations, and the fears they induce, can make a person with Parkinson’s related psychosis hostile. One common example: “There can be delusions of sexual jealousy where they feel like their partner is having an affair, even though they’re not,” says Barrett. This can be very frustrating for partners who are also caregivers.

As a caregiver, you might struggle to cope when your loved one insists that their hallucination or delusion is real. That said, you don’t have to fight every battle. “When reasonable, it might be better to not always contradict your loved one when the hallucinations or delusions are fairly fixed, because that can just become a point of contention and argument that increases the stress for both the patient and caregiver,” says Barrett. For example, if your loved one is falsely accusing you of cheating or stealing from them, you might want to correct them. But if they mistake a lamp for an animal or see a monkey in the backyard and they aren’t bothered by it, resist the urge to correct them just for the sake of correctness. “If they want to know, ‘Is that real or not?’ then of course you can clarify,” says Barrett. But if they’re not bothered or upset by their hallucinations, it’s OK sometimes to just let it be. However, if the psychosis is bothersome and interfering with your loved one’s care, help them talk with their doctor about treatments that could help. And above all else, remember to take care of yourself. Research published in 2015 in Parkinsonism & Related Disorders shows that psychosis is particularly burdensome for caregivers of people with Parkinson’s disease. If that’s the case, don’t hesitate to lean on others, such as your family members or hired help, for support.