Could dad's unwarranted jealousy be dementia?

DEAR AMY: Have you ever heard of men getting jealous or paranoid as they age? My father is in his mid-70s and for several years has accused my mother of ogling other men. He has written her letters about how hurt he is and even made a list of men she has supposedly "made eyes at." Every time they attend a social event with one of these men (close family friends, relatives) there is inevitably an angry conversation on the way home about how my mother misbehaved. My siblings and I are flabbergasted at this since my mother in no way acts any differently around these men. She is angry and hurt by my father's accusations and comes to us for support. We can tell that my father genuinely is hurt by his perceptions of my mother's "infidelity," but I can't stand to see my mother accused like this. It is so difficult to talk to him about this because he believes we are taking her side and ignoring "obvious signs" of her behavior. This is tearing us apart, and the whole family is worried. Is it possible that his odd behavior is a result of aging?Worried SonDEAR WORRIED: Your father might have the onset of dementia - or another illness affecting his reasoning and reactions. You should make sure he is evaluated and screened by his physician. Go with him to this appointment.

You also should remove your mother's behavior from the equation.

According to everyone, she is completely innocent, so there is no need to discuss, explain or describe her actions.

You should do everything possible to advocate for and protect your mother. She's at risk.

Don't stand by and attempt to reason with someone who may have lost the ability to discern. Step in to see that he is given a mental-health screening and make sure your mother knows to contact you if she is afraid.