Perhaps the saddest part of Alzheimer’s disease is that you watch almost all of the personality and characteristics of the person who is afflicted slowly disappear before your eyes. As many say, it’s a slow, painful disappearance that may not be fully understood until much later.

In the July/August issue of More magazine, Roxana Robinson shares how her mother, described as “the loving one” of her parents, slowly but surely change. Initially, the evidence was hard to see – an untidy home, mixed up doctor’s appointments. Robinson recounts how her mother emotionally accused Robinson of meddling by changing a doctor’s appointment; in fact, Robinson had called to confirm the appointment. “My mother had never before called to criticize me. She had never used that angry accusatory tone with me. She never used the word hell. Only twice in my life had I heard her weep.  She had never hung up on me,” Robinson said. “Who was this mother?”

CBS Correspondent Barry Petersen also believes he missed the earliest signs of his wife’s early onset Alzheimer’s in his new book, “Jan’s Story” (which was provided as a review copy to me). His wife, an accomplished news reporter, was finally diagnosed when she was 55. However, Petersen suspects that she was starting to show symptoms while in her 40s.

Petersen describes that while living in Moscow, Jan became angry that CBS sent another reporter to that bureau. “It didn’t really affect Jan because there was more than enough work for all of us,” Petersen wrote. “But she got angry  at the idea of competition, and although that was understandable, the anger never faded. She never adjusted to the situation, and she reacted in a way very odd for someone who relished taking on a challenge . . . she withdrew. Now I look back and wonder . . . was that the beginning of her own suspicions that something was wrong, the beginning of her avoiding new challenges, so no one would notice the things she would have trouble doing? Was the arrival of a new reporter not a cause, but an excuse to hide what she felt were faltering writing and reporting skills?”

In thinking back to those earlier times before the formal diagnosis, Petersen also identified Jan’s increasing avoidance of adventure and loss of interest in meeting new people. "In 2000-2001, my daughters from my first marriage -- Jan's stepdaughters -- started saying to me, 'Dad, she's really repeating herself a lot,'" Petersen told me in a recent interview. "I really was very good at dential and I said, 'Well, she's tired; well, we're jet-lagged.' I think Jan one time said it was the barometric pressure changing that was causing her to be a little more foggy."

In my own case, my father may have seen some of the signs in my mother earlier, although most of what he described seemed like mild cognitive impairment and didn't warrant a tremendous amount of concern. Dad noted that Mom was increasingly at a loss for words, often resorting to calling everything a “thing”. He also described how she would overpack clothing as well as multiple types of dog treats for a weekend get-away. I also noticed that Mom stopped getting together with her friends and rarely sewed anymore (which had always been one of her favorite hobbies). These things didn’t really worry me.