Susan O’Halloran’s Journey with Early-Onset Alzheimer’s
Susan O’Halloran had always loved her work. As a medical scientist in haematology, she spent decades analysing blood samples, diagnosing diseases and solving complex problems under pressure. “I was probably one of the few people there who absolutely loved coming to work,” she says.
So when she began feeling an overwhelming fatigue in her late fifties, she explained it away. “It was dreadful tiredness,” she recalls. “There was a lot of brain work in my job, a lot of analysing and thinking, so I thought maybe I was just exhausted.”
Then came the memory slips. Susan believed she was doing everything correctly at work, until colleagues began to notice something was wrong. “If someone asked me what I’d just done, I couldn’t tell them,” she says. “My manager said, ‘Your supervisors have lost confidence in your work. You’ve got a memory problem.’”
Susan was 58. She was still working full-time. And like many women her age, she wondered if what she was experiencing could simply be menopause, stress or getting older.
“It’s really easy to explain all those symptoms away,” she says. “You think, ‘It must be menopause,’ or ‘Everyone says you lose your memory a little bit as you age.’”
What she couldn’t ignore was her family history. Her father had Alzheimer’s disease, as had his sister and mother. “I thought, I’ve got to get this checked out,” she says.
After six weeks of neurological testing – including cognitive assessments, MRI scans and analysis of protein levels in her cerebrospinal fluid – she was diagnosed with early-onset Alzheimer’s disease.
“I still didn’t believe it,” she says. “I felt okay. I had memory problems and I was tired, but I thought, no.”
For Susan, the distinction between ‘normal’ brain fog and dementia was devastatingly clear – but for many women, that line is far blurrier.
Why Midlife Brain Fog is So Common
Forgetfulness, poor concentration and mental fatigue are among the most common complaints women report during perimenopause and menopause. According to Associate Professor Susanne Roehr from the Centre for Healthy Brain Ageing (CHeBA), this is both real and expected.
“It’s very common for women in midlife to notice changes such as forgetfulness or trouble concentrating, especially during perimenopause and menopause,” she explains. “This kind of brain fog is usually mild, comes and goes, and tends to happen in certain situations, for example when you’re tired, stressed, or juggling a lot.”
Research shows oestrogen plays an important role in memory, focus and learning. As hormone levels fluctuate during perimenopause, brain efficiency can temporarily dip. “These hormonal ups and downs can affect how efficiently the brain works,” Associate Professor Roehr says.
Add disrupted sleep from night sweats, increased stress, low mood and the mental load many women carry in midlife, and cognitive strain becomes almost inevitable.
The scale of the issue is significant. Surveys suggest more than 80 per cent of women report brain fog during the menopausal transition. Yet despite how common it is, the experience can be frightening – particularly given the growing awareness that women are disproportionately affected by dementia later in life.
How Dementia Is Different
While brain fog feels alarming, experts stress that dementia in midlife is uncommon.
“Dementia at this age is rare,” Associate Professor Roehr says. “Eventually, all women go through menopause, but only a small proportion will develop dementia.”
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GP and Dementia Australia Honorary Medical Advisor Dr Marita Long agrees. “Most people with dementia are over the age of 65,” she says. “We do have younger-onset dementia, but usually there’s a very strong family history.”
The most important distinction, she explains, is function. “With normal ageing or brain fog, you might forget where you put your keys, but you can think back and retrace your steps,” Dr Long says. “With dementia, there’s an impact on function – you are no longer able to perform your normal activities.”
Another key difference is awareness. “People with brain fog are acutely aware that something isn’t right,” Dr Long explains. “They come in embarrassed, worried, saying they’ve missed appointments or forgotten names. With dementia, it’s often someone else reporting those changes.”
Crucially, dementia is progressive. “It has to get worse over time,” Dr Long says. “Brain fog linked to menopause often comes and goes and, for most women, improves after menopause.”
When Symptoms Interfere with Life
For Susan, the moment her symptoms crossed that line was unmistakable. “Problem-solving was difficult,” she says. “I’d get disorientated and there were a couple of times where I had no idea where I was. That was really frightening.”
She also struggled to follow conversations. “I wouldn’t remember what they’d just said,” she explains. “It was all short-term memory, things you’ve just learned or been told.”
Looking back, she believes symptoms had been present for years. “The neurologist said, ‘You’ve probably had this for over 10 years,’” she says. “You can have it for a long time before it starts infringing on your life.”
Like many women, she had explained earlier signs away. “I explained everything away,” she says. “I was still able to work and raise my family.”
That instinct – to minimise and push through – is common. “As women, we think everything is stress,” Susan says. “We’re doing too much.”
Dr Long says this tendency, combined with age bias, can delay diagnosis. “A lot of people still associate dementia with normal ageing,” she explains. “So when symptoms appear earlier, we don’t think about it.”
Ruling Out What Can Be Treated
One of the most important steps when women present with cognitive concerns is excluding reversible causes.
“When we think about cognitive complaints, we always look for things we can treat,” Dr Long says. “Iron deficiency, thyroid dysfunction, sleep disorders, depression and anxiety can all affect cognition.”
Most women experiencing menopausal brain fog will still perform well on formal cognitive testing. “There’s a subjective sensation of significant change, but no objective evidence of impairment.”
That’s why experts stress the importance of taking concerns seriously – without jumping to conclusions. “If problems don’t settle, seem to be getting worse, or start affecting day-to-day life, it’s reasonable to seek medical advice,” Associate Professor Roehr says.
Protecting Brain Health at Any Age
While dementia remains a major health issue for Australians – with women accounting for around two-thirds of those living with the condition – midlife is also a powerful window for prevention.
“Research suggests up to around 45 per cent of dementia risk is linked to factors we can influence,” Associate Professor Roehr says. “Physical activity, managing blood pressure and blood sugar, staying socially and mentally engaged, and looking after sleep and emotional wellbeing.”
Susan’s neurologist offered similar advice. “He asked me what I love to do,” she says. “I said I love singing, music and dancing.”
She now dances several times a week, goes to the gym daily, volunteers with people living with dementia and has learned to accept help through the NDIS. “Accepting help was really hard,” she says. “But once I did, my life changed again.”
Her advice to other women is simple. “Trust your instinct,” she says. “If something is really starting to interfere with your life, it doesn’t hurt to get it checked out.”
As Dr Long puts it, “Don’t just suffer through these symptoms. Go and see your GP. Advocate for yourself. And if you don’t get the answers you need the first time, keep asking.”
