Of all the various aspects of my mother's deterioration, the one that perhaps disappoints me more than any other is the hoarding.

Just yesterday, as Regan and Cassy left the house, mum, pointing at the colouring book that Cassy had brought with her, said: 'And where's she going with that?'

Mum had had a very fraught morning, and was certainly in a bad mood, but this kind of suspicion - an apparent belief that people are cheating her or taking things from her - is like sand in the shoe; it discomforts, and introduces friction where there should be none.

Of course, we are taking things from mum, and in some way she may be aware of this.

But then there are the other aspects.

She hides her handbag in various places, and usually forgets where she puts it. Luckily, I know the most frequently used hiding places and can delight her by finding what she often thinks was lost forever.

She secretes bits of chocolate under her pillow, in the drawers of her bedroom, and in a small cabinet that sits beside her armchair. We find them weeks or months later, furry and whitened with age.

She intercepts letters not addressed to her, and hides them behind plates on the sideboard or in her bedroom. Touch them at your peril.

She reacts very negatively to any attempt to clear her room of the old and dilapidated, the mouldy or broken.

She wouldn't let me throw away the hundreds of rubber bands that she and dad had accummulated over the years. Nearly every day the postman delivers letters with a thick red rubber band around them. Some of those in mum's collection were so old that they resembled twigs - brittle, gnarled and hardened things. They filled the drawers of the escritoire to capacity. The only way I could deal with them was to start a giant rubber band ball. It is now about the size of a handball and is, incidentally, very bouncy. Mum seems to like the idea that she has all her rubber bands, and the very fact of the ball seems to help her disregard the other fact, that many other rubber bands have simply been thrown away.

Sometimes, when I am packing up my things, about to leave the house, I see her eyeing what I put into my backpack.

Dad has a touch of this disease too. Once I cleared the yard of all the broken and rusty garden furniture. The council was doing the rounds and clearing away all such stuff. Outside the garden fence I made a pile of what I considered rubbish. The next day I found it all under the deck again. Dad had very deliberately and with great effort carried everything back into the yard.

But in the final analysis, this might be my problem, not theirs. I have always been a minimalist. They have always gathered things around them. We are incompatible in that way. As a teenager, I was appalled at my parents' predisposition to buy lots of tacky souvenirs in all the countries they visited. The house is full of cheap wooden carvings, tarnished copper pictures, and crude paintings. If only all that expense had been put towards one or two beautiful antiques, I wished. If only we had some space in which to admire them.