His personality has completely changed. Where has the person I knew gone?

My father was always calm and polite, and now he says harsh things, has no patience for anything, and sometimes seems like a different person. I struggle to recognise him.

For many carers, seeing a parent's or spouse's personality transform is more painful than memory loss. And it's important to start here: what has changed is the brain, not their will. The brain areas that regulate patience, empathy, and social filtering are affected by the disease — in some dementias (like frontotemporal dementia) these are even the first to suffer.

What helps day-to-day

Try to separate the illness from the person: when you hear a harsh phrase, remember that it's the symptom speaking. It's not easy, and you won't always succeed — and that's perfectly fine. Avoid confronting or correcting them ("you weren't like this before"): the person cannot go back through willpower, and confrontation only creates frustration on both sides.

Look for moments when the person you know still appears — with music, photographs, smells, and old routines. Emotional memory lasts a long time: even those who no longer recognise faces continue to feel affection and security.

Caring for your grief

There's a name for what you're feeling: anticipatory grief — mourning someone who is still physically present. It's real and deserves space. Talk to someone you trust, a carers' group, or seek psychological support. If personality changes are sudden or very pronounced, speak to their GP: sometimes there are treatable causes (pain, infection, medication side effects) that can worsen behaviour.