19/05/2017 04:00 BST | Updated 19/05/2017 06:03 BST

People With Dementia Are Still People - We Must Remember That

Yui Mok/PA Wire

When people ask me what My Family: Not The Sitcom is about, you might expect the answer: my family. Which it is. But I actually tend to give the answer: memory. That is really what the show is about. I think people assume the show is mainly about my dad and his dementia, having seen or read stuff about that, but in fact the starring role goes to my late mother's sex life. Because I noticed at her funeral that everyone was telling me that my mother was wonderful, and then I realised that thing - the propaganda of death, that all we are allowed to say about people we have loved and lost is that they were wonderful - erases who they were out of existence. If you really want to preserve the memory of someone you have loved and lost, then what you need to call up is their weirdnesses, their madnesses, their flaws: because that is what made them a human being, and the dead, despite what we might like to think, are not angels.

However. The supporting role in the show is very much my father's, and he is seen through the lens of his dementia. Again, it's not straightforward. My father has Pick's Disease, a type of frontal lobe dementia, the symptoms of which involve various anti-social behaviours, including swearing, impatience, irritation, apathy and mood swings. And, as I say in the show, when the neurologist first told me this list of symptoms, I said: sorry, does he have a disease, or have you just met him?

I say that because I also believe that dementia is not a reason to idealise someone out of existence. My father has always been a sweary, impatient, irritated, lazy bloke. His loss of memory hasn't in fact lost who he is, like dementia can sometimes do. It's the opposite: it's turned the volume up on who he is - when the disease first took hold of him, he became like a Spitting Image puppet of himself.

So really the show is about how you remember people, and about how people who have no memory can in fact still be themselves. Which is why, when Alzheimer's Society invited me to be an Ambassador, I said yes. Obviously, they do loads of good work, and obviously I'm a huge advocate of the need for society to unite against dementia, because it affects us all.

It's also because I'm keen to change the conversation about dementia. Dementia, like death, has its own propaganda. For many years, in film and TV, it has been represented in exactly the same way, as men and women with tartan blankets on their laps, staring vacantly into space. Like the idealised dead, we have only been allowed one idea of dementia. But actually, it is a dark rainbow: there are many different types of dementia, and it appears to me that people "dement", (if that's even a word) in their own way. My father is very much still in there: in fact, a lot of the time, he's out there, his personality tumbling out of him, unconstrained by whatever old constraints of inhibition and self-control used to apply.

However difficult and hard to deal with that is, it has its own energy, its own life, and it shouldn't be consigned to the nothingness myth of what dementia isn't.

My point being: my show is about memory. I think it's important how we remember people. And those of us with our memories still vaguely intact need to remember that people with dementia are still people.

David Baddiel is Alzheimer's Society's Ambassador and backing the charity's United Against Dementia campaign. Find out more at My Family: Not the Sitcom is running at the Playhouse Theatre until June 3rd.