DEAR ABBY: My brother has been married for 25 years to “Gayle,” who has alienated herself and their family from everyone, including her own siblings, our siblings and the rest of our family as well. She limits when, where and with whom he can spend time.

Gayle nearly always has a nasty comment or barb and picks someone to fight with at every family gathering. Rather than deal with this, my family and our siblings’ families have distanced ourselves, which is especially sad because my brother and Gayle have college-aged children with whom we enjoy spending time.

Abby, something happened recently that makes me wonder if it’s time for someone to intervene. My brother has an increasing number of false memories about things that never happened in his life — particularly ones in which he has supposedly been grievously wronged by me. Please share some advice. — MISSING MY BROTHER IN NEW ENGLAND

DEAR MISSING: The topic of false memories is not one about which I am knowledgeable enough to comment. I do, however, know they happen sometimes as people age.

Your brother may be experiencing symptoms of dementia and should be examined physically and neurologically by his doctor. Discuss this with the rest of your siblings in the hope that if ALL of you suggest this to your brother’s wife and adult children, it may get through to her. But don’t count on it if she has worked during their entire marriage to isolate him from all of you.

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Dear Abby is written by Abigail Van Buren, also known as Jeanne Phillips, and was founded by her mother, Pauline Phillips. Contact Dear Abby at www.DearAbby.com or P.O. Box 69440, Los Angeles, CA 90069.