This is the fifth in a series of articles about the issues that arise over time for older people who experience mental declines - and how you, as a family member or friend, can help.

Stephanie described her mother's decline to me. What follows is an edited extract from her comments:

"By the time my late mother was around 80, we were seeing signs of word-retrieval issues and a memory that seemed to be slipping.

"My sister and I were incredibly frustrated and very scared, as neither of our parents wanted to address the issue. My father simply covered for her, insisting that she couldn't hear well rather than acknowledging that she couldn't process what she was hearing.

"There were days we felt like talking to them about any of it was like banging our heads against the wall. 

"In 2004, when my mother was 82, my 59-year-old brother passed away unexpectedly on Christmas Eve, and, my mother's dementia began to worsen. It was as if the trauma of losing her son accelerated the process.

"We became alarmed when she argued that the blue flowers we had selected for my brother's memorial were pink. We let it go to avoid upsetting her or my father, but we knew there was cause for concern.

"Four years later, at the age of 86, my mother lost her husband, my father, also on Christmas Eve 2009.

"From here, my mother's dementia took off at warp speed.

 She wanted to stay in her home, surrounded by her own things and her beautiful gardens. But now she was living alone. I visited regularly and had help come daily.

"My mother began setting things aside that she was planning to send to my late brother. She wouldn't eat her meals because she was waiting to eat with my late father.

"I took my mother for a geriatric evaluation. Humorously, after one of the "tests," my mother reported to me that she "got a perfect score!" The medical doctor, however, informed me that she wasn't even able to go very far into the testing, and that continuing it would only have frustrated and upset her.

"During the time that my mother was living alone, I hardly slept. I was rearing my own three teenagers, making routine 40-mile trips to my mother's, and, lying awake at night worrying about everyone.

"Within three months of my father's death, it was clear that I had to do something. By this time, she had locked herself out in the freezing Ohio winter, had accused all the help of stealing from her, and, had contracted a urinary tract infection (UTI) that seriously compounded the dementia.

"She ended up in a geriatric psych ward in Cincinnati, where she remained for a full month while they cured the UTI and evaluated her.

"Of course, the dementia continued to worsen, but in an almost good way. My mother's dementia seemed to protect her from her harsh reality. Each time my kids and I visited, (and, happily, she always knew us), my mother would report that she had been visited by my late father, my late brother, my long-deceased grandparents, etc.

"My mother would talk about my brother being remarried to his former wife and about my being back together with my own ex. It was as if, somehow, the dementia allowed all the things my mother perceived as 'wrong' to be set 'right' before her passing."

The way events unfolded for Stephanie's mother is not unusual.

You might not realize that infections can cause mental confusion or delirium. And although we tend to think that the effects of infections are temporary, the Alzheimer's Society in the UK reports, "any infection could speed up the progression of dementia and so all infections should be quickly identified and treated."

On a similar note, a number of people have told me that the death of a family member seemed to lead directly to a parent's rapid mental decline.

Next week's column will talk about some steps you can take if you realize that you have a relative who is starting to have trouble making sense of daily activities that used to be easy.

-- Next -- 074. How to Help Elderly Relatives Manage Their Finances