I really would rather die than exist without memory or recognition

I don't normally prompt people to end their life but Moore was playing Alice in Still Alice, the story of a woman struck down in her prime by early onset Alzheimer's.

When her mind was still functioning she'd recorded a video message to herself for her to view when she could no longer answer some simple questions. It directs her to the dresser in her bedroom where she will find a bottle of pills. "It's very important you swallow them all ... then lie down and go to sleep."

With her mind already fractured, obeying the message took several attempts. She'd listen, climb the stairs and forget what she had to do.

Then, just when she poured the pills into her hand, a helper arrived and called out "Hello?" The audience emitted something between a gasp and a wail as the tablets scattered across the floor.

By the end of the film Alice had left Alice. The body she used to inhabit was being taken for a walk by a daughter she no longer knew. Years stretched ahead.

Why? I know. It's easy to say a fictional character should have bowed out of life but dementia is rarely so neat. First, the person suffering is loved by their family and, secondly, they don't just fade seamlessly into oblivion. They have ups and downs and sometimes flashes of lucidity.

John Suchet's beloved wife Bonnie died two weeks ago. The harsh truth is that I could as truthfully write that Suchet's wife died years ago.

He wrote a book about her devastating illness. He charted it from the moment she got lost at an airport, when he gave up work to care for her, then her admittance to a care home and to the acknowledgement that she no longer knew him. She smiled when he arrived to visit but never asked about him when he left, which was one of many aspects of her condition he found both consoling and heart breaking.

Dementia is a catch-all description for a cluster of cruel, terminal illnesses. There are 88,000 sufferers in Scotland, nearly 3,200 of them under the age of 65. But the number affected must be multiplied by family and friends.

By 2031, in just 16 years, we can expect the number with the condition to rise to 160,000. It's a demographic nightmare, even if the economy soars. The average life expectancy of a person with Alzheimer's is 10 years. Whether their care is delivered at home or partly in residential care the cost is astronomic in human as well as financial terms.

The question (not one we have heard much about in the General Election campaign) is: how do we prepare for it?

In case you are wondering, I'm not about to suggest mass suicide. Nor am I going to argue for assisted dying. But I do wonder if we need to think carefully and compassionately about the quality of care people are being offered and will be offered. It is patchy at present but greater numbers mean huge rises in costs and that usually translates into lower standards.

So how do we square that circle? As part of the solution don't we need to be honest about the level of life-prolonging medical intervention that is appropriate?

I know that, if I become one of the unfortunate sufferers, I really would rather die than exist without memory or recognition. And I would rather die than have my family care for me in such a state. Others, however, will feel differently.

Surely, before we draw up the necessary guidelines, it is both right and proper to establish how and to what extent people will wish to be treated while they have the capacity to state their preference.

I applaud new NHS guidelines in England urging GPs to draw up end-of-life plans with people over 75, as well as younger patients suffering from cancer, dementia, heart disease or serious lung conditions.

There is criticism about the way some practices have been cold-calling to ask unsuspecting patients whether they would want to be resuscitated. That is a crass approach to a problem that needs to be handled with sensitivity. But, given the scale of the population challenge that lies ahead (England's ageing population is 10 times the size of ours), isn't it sensible to establish what we all want?

We make a will to distribute our assets according to our wishes. Why not make end-of-life planning as commonplace to express our wishes about how we would prefer our final weeks and days to be handled, fate permitting?

For those who have already gone beyond the ability to be consulted, we are obliged to do our best. We are falling short.

In Scotland, according to government policy, dementia patients have a number of rights including "to have access to a full range of palliative care services and good quality compassionate care towards the end of life". In reality, families are dependent on what is available from the health and care agencies in their area.

For instance, hospice care is a rarity for dementia patients. But it is precisely the gentle atmosphere of a hospice with attention to personal needs and a watchful awareness of the need for pain relief that would most benefit sufferers and their families.

The charity Alzheimer Scotland agrees. It is working on a model of care for people with advanced dementia that will be launched later this year. Its director of policy and research, Jim Pearson said: "There is much we can learn from our colleagues who have developed palliative care and end-of-life care for people with cancer. However it is our view that we must understand the unique nature and complexities in delivering care for people with dementia and develop a specific model to ensure consistent care is provided in Scotland."

It's true that dementia poses unique problems. A Marie Curie report, Living and Dying with Dementia in Scotland, states the bald facts: "Those with moderate or advanced dementia can be physically aggressive, experience hallucinations, be agitated or anxious and have sleeping disorders. The symptoms can cause emotional and physical stress for the terminally ill person and their carers.2

There is a pilot scheme running in five areas of Scotland to provide integrated care that allows people to remain at home for as long as possible, run with the help of a dementia practice coordinator who oversees continuity of care. Where the family is well supported this could be an optimum solution for the patient who will remain in familiar surroundings; also for the budget holder.

Consistent care is cheaper because it avoids costly crisis management. But care at home for someone with a moderate to severe stage of the illness will be a living hell for carers who are not well supported.

The nature of the illness also makes hospital a challenging environment, especially since medical staff are often stretched and rarely have specialist training. We also need to be blunt about asking ourselves whether it is always kind or right to offer medical interventions that might alarm and further distress the patient.

At present, most dementia patients die in nursing homes. Perhaps what we need is to import the training and atmosphere of hospices to nursing homes.

It's a depressing subject. It is something we'd rather not think about. Since dementia is bound to affect many of us or those we love, shouldn't we be better prepared?