IT can be really hard to admit publicly that you have been given a diagnosis of dementia. Let’s face it: who wants to be thought of as demented?

The word itself really doesn’t help. Dementia – it sounds terrifying.

I knew pretty much nothing about the condition up to the day I sat in my parents’ front room listening to the consultant pronounce the verdict that my father had been diagnosed with Alzheimer’s, the most common form of dementia.

I have spent most of my adult life working alongside my father. When my mother died – three weeks after that moment in that front room – it seemed natural that I should be the one to try to help him through this part of his life.

So we embarked into this unknown together. After five years, we have discovered it is possible to live well with this diagnosis but, the way things are in Britain today, it isn’t easy.

In the dictionary my mother was given when she was at college in the 1940s, “dementia is a species of insanity consisting in feebleness of mind”.

By the 1980s, in the dictionary my mother gave me when I was at college, it was “a state of serious emotional and mental deterioration of an organic and functional origin”.

Now in his late eighties, my father still lives independently, with some support, in his own home.

He is perfectly rational – just as he has always been. If you care to ask him, he has well considered opinions.

The principal symptom of his condition is that every day, 24/7, he has to cope with the misfiring of his short-term memory and the confusion, and sometimes panic, that gives rise to.

A hundred years ago, my father would have been considered a marvellous old man – a bit forgetful, perhaps, but doing extremely well for his advanced age.

Today he is labelled a vulnerable adult suffering from a degenerating condition for which there is no known cure.

The perception matters. In one view you are dealing “marvellously” with the deficits of old age; in the other you have lost yourself and there is no hope.

After five years of asking questions about what science knows about dementia, it seems to me that the present sum of knowledge is pretty limited.

Scientists can give you considerable detail about the organic deteriorations in a demented brain at autopsy after life is extinguished – but they cannot predict how well one individual “me”

with the condition may be enabled to live out the rest of their life.

Supporting my father as he ages with this condition has been an eye-opener for me.

What has struck me most is how the assumptions of the people around him impact on his ability to live well with the condition.

From my own observations, the greatest enemy is the destruction of your sense of self. The way our society responds to dementia at present is very isolating. To be constantly reminded by the treatment of others that you are on a degenerating path to insanity does tend to undermine your self confidence.

People treat you differently; they look at you with concern; they question your judgement; they don’t know how to talk to you.

They leave you increasingly on your own. In that atmosphere, when you lose your keys, you grope for a word, you wonder what you are doing – you panic and you may be inclined to give up.

That’s it. You are lost.

If, on the other hand, you are surrounded by people who are aware that you can grope for words – but that doesn’t mean you are stupid; or that you may not recognise them until they tell you who they are – but that doesn’t mean you don’t want to remember them; or that if you get in a stew because you don’t know what you are doing in that place – that doesn’t mean you are insane; and if, instead of treating each encounter as a crisis, the people you meet take the time to help you fill in the missing information and even enjoy your company – that is transforming.

Your confidence is returned to you and you are no longer lost.

There will be more than a million people with dementia in Britain by 2021. If you or I live to 70, we have a one in 25 chance of developing the condition; if we live to 80, a one in six chance.

The way we are responding to the disease cost the UK more than £23bn last year.

It also causes unnecessary misery to hundreds of thousands of people. There is a better way.

And so I am writing this in support of the Alzheimer’s Society’s campaign towards achieving Dementia Friendly Communities.