EMMA Thompson's grandmother sank into an eccentric and mildly amusing dementia.

She would put bacon in her knicker drawer and her knickers in the fridge or declare: "I thought dementia was a friend of mine."

Others are not so fortunate. For too many the illness brings confusion and fear. I watched one dear friend shout at her helper and fail to recognise her closest relatives. What the experience gave me was a tiny glimpse into how terrifying it must feel when your mind slips its moorings. In Scotland almost 86,000 people are on that journey. They have dementia with everything that brings in its wake, for them and for their families.

This week Thompson said there should be a care nurse in every street to help monitor dementia sufferers and to support those who look after them. Is she right?

She watched her mother Phyllida Law "go slowly bonkers" as she looked after Thompson's paternal grandmother for 17 years. She says carers need a nurse who can drop in for a cup of tea, who can be a source of support and information.

Is it the best way forward? Is it needed in Scotland?

Cast your eye at the Scottish Government's policies. Read its stated aims and intentions and you will think this is the best country in the world in which to grow old and increasingly confused. The rights of the individual, their dignity and well-being lead the thinking.

But there is the stated intention, there is even legislation - and then there is reality. The shortfall is huge. It matters because 60% of people with dementia (around 50,000 people) live at home. Most are cared for by relatives but, as society changes, an increasing number live alone.

Enabling sufferers to stay at home is compassionate, since few people long to end their days in an institution. If it is handled correctly with well-trained staff who grow familiar with their client, it is as ideal as this illness permits. But provision is patchy.

A helpline run by Alzheimer's Scotland receives thousands of calls a year from family carers who have no-one to turn to; who feel no-one understands. They struggle to get good quality care for their relatives, are confused over welfare rights and access to benefits. As carers they feel abandoned and isolated.

Caroline Brown, whose parents both developed the disease, found support poor.

She understood little about Alzheimer's disease when her mother was diagnosed and so allowed her to be taken immediately into residential care - a matter of ongoing regret.

When, three years later, her father was diagnosed with vascular dementia he was visited at home by carers. They would ask if he had eaten and taken his medication. Yes, he told them. Yes he had. They ticked the boxes and left.

"The visits were more like five minutes than 15," his daughter said. When he became ill and needed hospitalisation she found the meals she had provided for him still in the fridge and his drawer full of medicines.

"Everything was a fight. I was running between work, the hospital and the care home." Meanwhile her husband and children also needed her. Eventually she argued her father into a place at the same care home as her mother. "While all this was going on I cried for three years."

Eventually she joined the National Dementia Carers Action Network (NDCAN). She is convinced that what Scotland needs is a return to community. She wants to encourage neighbours or volunteers to drop in for a cup of tea.

It's a fine aspiration. But is it realistic? My experience, having seen my sister be the main carer for my mother until her death aged 102, is that family carers are applauded but are left carrying the can.

They are an unsung army whose combined efforts save the statutory services more than £10bn a year. Like Caroline Brown, they don't simply shop and cook and cheer along their elderly or demented relative. Most soon discover that the illness is not their only concern.

They find they have to acquire legal and medical knowledge and a working understanding of the care system. They need stamina and stubbornness to wade through the layers of bureaucracy that lie between their loved one and the help they need.

My mother was fortunate in that she remained lucid until past her 100th birthday. Her care was excellent because my sisters and I became her advocates in navigating the system. Our persistent voices secured the help she needed.

As with dementia, goalposts shift as age takes its toll. Needs increase as state funding shrinks.

But in long-term care, state help is essential. For example, an overnight carer costs around £100. For someone with mid to late-stage dementia that's £700 a week. But if the family carer is on duty every night, it means they are "on shift" 24 hours a day.

Try being severely sleep-deprived while caring for a dependant who asks the same question 100 times, who can't remember the way to the toilet or who stares around the room they have inhabited for decades and demands to know where you have taken them.

Try it when you know tomorrow will be worse instead of better. Try it when you know it could carry on for years and years to come. Try it when you have become socially isolated and visiting carers have no time to chat.

There is no better recipe for burn-out, for frayed nerves and decreasing levels of tolerance. If sharp words escape, guilt follows and after it comes depression if not despair.

The carer goes "slowly bonkers" like Phyllida Law did, or worse.

It is a sorry recompense for the loving and dutiful instinct that first motivated the carer. It shouldn't ever come to that but it will happen to more and more of us unless we face up to this crisis of care.

In April, Scotland introduced a one-year support structure which kicks in immediately after dementia is diagnosed. While still lucid, sufferers can take decisions about their own future. They are given a named link worker to help guide them.

No-one is yet certain what will happen after the first year but it is an important start, especially for the increasing number of people who live alone and have no family support.

There is clearly a will at Government level to deal with dementia decently and caringly. Unfortunately delivery is patchy, understanding is limited and although many families are living with the illness, they have not discovered the power of their united voice.

Would a nurse on every street solve the problem as Emma Thompson suggests? It would help. Better still, says Alzheimer's Scotland, is its eight pillars approach - an integrated health and social care model that addresses the physical, environmental and social needs of the person living with dementia alongside support for their carer.

What we are talking about is a society that does more than pay lip service to the selfless care offered by people like Phyllida Law - funding support for them and lending them a hand. It is too harsh a path to walk alone.