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Are They Jealous? Do They Cry or Laugh for No Reason?

Abnormal crying and laughing are some of the strange behaviors in dementia.

In our first post on behavior, we talked about how and why frustration, depression, anxiety, and not participating in activities are common in dementia. In our last post, we tackled the thorny issues of apathy, irritability, agitation, aggression, combativeness, inappropriate behavior, willfulness, and sundowning. In this post, we’ll discuss why problems occur with jealousy and paranoia, frequent crying and laughing, and changes in diet.

Jealousy and paranoia are common in dementia

Any of us can feel jealous or paranoid from time to time. You see two people whispering together and glancing your way and you wonder if they’re talking about you. Your spouse is making jokes or laughing a bit too loudly with that attractive person and you wonder if they are flirting. The emotions of jealousy and paranoia are involuntary, but are usually rapidly and appropriately suppressed by the reasoning part of your brain, which performs a quick reality test and concludes that the two people whispering and glancing your way are more likely just looking in your direction rather than at you, and your spouse is not flirting or—even if they are—it’s perfectly harmless and nothing to get upset about.

Jealousy and paranoia are common in dementia because of the combination of two problems. Memory problems can cause jealous and paranoid thoughts to develop, and impaired reality-testing allows these thoughts to persist and grow. For example, you may run out to go to the corner store to buy your spouse’s favorite cereal. You return with the cereal 20 minutes later, pleased that you have done something thoughtful for them. Your spouse, however, being unable to accurately remember the passage of time, accuses you of being gone for hours and having an affair with the neighbor. You try to reason with your spouse but, because their ability to reality-test is impaired, you cannot talk your way out of the situation.

Crying or laughing too easily or inappropriately may occur in dementia

Are you worried that your loved one is depressed because they cry spontaneously or with little provocation? Are there times when they laugh when nothing is funny or when it’s not socially appropriate to do so? If you see either of these patterns in your loved one, it is worth considering whether these behaviors may be due to the dementia. Doctors often refer to this condition by the terms pseudobulbar affect or pathological laughing and crying.

If your loved one is crying frequently, they may, of course, be depressed. But don’t assume that they are—ask them how they are feeling. If they tell you they are feeling sad and that’s why they are crying, then you know they are depressed. If, on the other hand, they tell you they are not sad and they don’t know why they are crying, it may be that the damage to the brain from the dementia has made it difficult for them to control their tears. Similarly, spontaneous, exaggerated, or inappropriate laughing could be due to your loved one thinking that something is very funny, or it could be that they cannot control their laughter even when they don’t think that anything is funny. Asking them is the best way to sort it out—which is important because the treatment will depend upon the cause, as we will see in future posts.

Changes in diet: Sweets, binge eating, and consuming unusual items

Think for a minute what you might eat if you could consume any quantity of anything you wanted at any time without consequences such as feeling full, becoming sick, or gaining weight. Can’t decide on two entrees in a restaurant? Order both! Tempted by that hot fudge sundae? Go ahead! Was it so good you’d like another? Go for it! Having lost the restraints on their impulses, many individuals with dementia will eat whatever sweets they can find, such as an entire box of cookies or a container of ice cream. Why sweets? It’s built into most of us; ask any 5-year-old. Some individuals with dementia may eat almost any food that is not locked up; one such individual with frontotemporal dementia we cared for ate a jar of mayonnaise, a box of cake mix, and an uncooked steak.

Summary for behavior issues in dementia

Declining abilities by themselves may lead to frustration, irritability, depression, anxiety, and not participating in activities. Depression and anxiety may also be caused by dementia directly. The front part of the brain is particularly important for behavior, enabling the pause between impulses and actions. It also enables thoughtful planning. Common problems in dementia include apathy, irritability, agitation, aggression, combativeness, and inappropriate behavior. Dementia can also lead to willfulness, jealousy, paranoia, excessive crying or laughing, and a change in eating habits. Cognition and behavior are generally worse at the end of the day for most individuals with dementia, a phenomenon often called “sundowning.” Lastly, impaired and disinhibited behavior may lead to safety concerns. In future posts, we will discuss how to manage these behavioral issues.

Key Questions:

I’ve never fooled around in my life. Why now, at 83 years old, is my wife is accusing me of having an affair?

  • Jealousy is common in dementia. Due to her memory problem, your wife may think you’ve been away for hours when you’ve only been gone a few minutes, and her impaired reasoning doesn’t consider your age and prior behavior.

Two months ago, he started laughing at the littlest things. At first, I thought it was sweet and he was just happy. But now it’s clear that he can’t control it and he’s laughing at things that really aren’t funny. Why does this happen?

  • Excessive laughing or crying, sometimes called pseudobulbar affect, is common in dementia. Although most of the time just this understanding is all that is needed, if it is becoming a problem there are medications that can help.

© Andrew E. Budson, M.D., 2020. All rights reserved.


Budson AE, O’Connor MK. Seven Steps to Managing Your Memory: What’s Normal, What’s Not, and What to Do About It, New York: Oxford University Press, 2017.

Budson AE, Solomon PR. Memory Loss, Alzheimer’s Disease, & Dementia: A Practical Guide for Clinicians, 2nd Edition, Philadelphia: Elsevier Inc., 2016.

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