When Mental Illness and Dementia Collide: A Guide for Carers
“I thought it was just her depression coming back,” said Liz, whose partner has lived with bipolar disorder for more than 20 years.
“She was sleeping all day, getting confused about her tablets, and sometimes accusing me of moving things. I kept thinking, it’s another episode. But when she started forgetting where we lived, the doctor said it could be dementia.”
For carers like Liz, it’s often hard to know what’s happening when someone with a long-term mental illness begins to change in new and puzzling ways. Are they relapsing — or could this be the beginning of dementia?
The truth is, it’s often both. And that makes caring even more complicated.
Understanding What Might Be Happening
People with mental health conditions such as depression, bipolar disorder, schizophrenia, or anxiety can still develop dementia as they age. Sometimes, early dementia can look a lot like mental illness:
- Forgetfulness may seem like lack of motivation.
- Confusion might be mistaken for a mood or psychotic episode.
- Suspicion or agitation could appear to be a relapse of paranoia.
This overlap makes it hard for carers to know what’s “normal” for the illness and what’s new.
If you’re noticing:
- New or worsening memory loss
- Trouble with daily tasks they once managed
- Getting lost in familiar places
- Personality or mood changes that don’t fit previous patterns
…it’s time to seek a medical review.
A GP, psychiatrist, or geriatrician can assess what’s happening, review medications, and check whether the changes are due to dementia or another health issue.
Tip: Write down specific examples of what’s changed and bring your notes to the appointment — it helps professionals see the full picture.
What Carers Can Do Day to Day
- Stay calm and observe before assuming relapse
It’s easy to think, “Here we go again.” But dementia affects the brain differently from mental illness.
Keep a small diary of what’s happening — when confusion or agitation appears, what was going on beforehand, and what helps settle things. This helps professionals distinguish dementia from psychiatric symptoms.
📘 Learn more: Dementia Australia – Recognising the Signs
- Keep routines simple and predictable
Routine brings security and reduces anxiety.
Try using visual reminders — calendars, labels, pill organisers — and stick to familiar routines for meals, medication, and sleep.
📘 More on this: Better Health Channel – Caring for Someone with Dementia
- Avoid arguing about what’s real
If your loved one insists on something untrue (“You stole my purse”), avoid arguing. Instead, validate their feelings:
“That must be upsetting — let’s look for it together.”
Arguing increases distress; empathy keeps trust intact.
📘 Practical strategies: Dementia Australia – Communication
- Review medications regularly
Older adults are more sensitive to medication side effects, especially antipsychotics, sedatives, and antidepressants.
Ask the GP or psychiatrist for a medication review every 6–12 months, or sooner if there’s new confusion, imbalance, or drowsiness.
📘 Guideline reference: NHMRC Clinical Practice Guidelines for Dementia
- Look after yourself
Caring for someone with overlapping conditions can be exhausting. It’s okay to ask for help.
Take breaks, talk to friends, and reach out for professional support when needed.
📘 Self-care support: Carer Gateway – Carer Wellbeing
Where to Go for Help in Australia
Dementia Australia
Provides information, counselling, and carer programs.
📞 National Dementia Helpline: 1800 100 500
🌐 dementia.org.au/carers
Carer Gateway
A national service offering respite, counselling, financial help, and emergency planning.
📞 1800 422 737
🌐 carergateway.gov.au
Your GP or Psychogeriatric Service
Ask for a referral to:
- A Memory Clinic
- An Aged Care Assessment Team (ACAT)
- Or a Geriatric Psychiatrist (often called a Psychogeriatrician)
📘 More info: Healthdirect – Memory Clinics and Dementia Assessment
Beyond Blue
For carers feeling anxious, depressed, or overwhelmed.
📞 1300 22 4636
🌐 beyondblue.org.au
Dementia Support Australia (DSA)
Free national service offering behaviour support for carers and aged care staff.
📞 1800 699 799
🌐 dementia.com.au
Final Thoughts
When mental illness and dementia overlap, it can feel like the ground keeps shifting.
You may lose the patterns you once recognised — and face new ones that don’t make sense.
But you are not alone. With professional guidance, clear routines, and supportive services, it’s possible to preserve dignity, calm, and connection for both you and the person you care for.