Coping with dementia is almost impossibly hard, the inexorable decline that accompanies it are unspeakably harrowing for all concerned. And with around 800,000 people already suffering from some form of the disease, and nearly 2 million expected to do so by 2050, the numbers are frightening. Even more alarming – as has been starkly revealed by this newspaper's series on dementia this week – is the inability of Britain's health and social care system to cope with the problem.

At its most basic, the difficulty is one of definition. Dementia is an illness that is so sprawling and still so widely misunderstood that our outdated categories for illness and infirmity have not caught up. Unless aggressive enough to be acknowledged as a mental health problem, it is considered to be an issue of social care alone, no different from any of the other frailties that go with old age. The result is sufferers all too often shuttled from one inappropriate facility to another, "a piece of lost luggage on a dementia carousel", as an Independent writer described her father's traumatic experiences.

Another central challenge is – of course – funding. Currently, all but the least well-off must bear the full cost of managing their condition themselves. Much-delayed efforts to reform social care by capping any individual's costs at around £35,000 are finally making some tentative progress. But even sweeping reforms to funding arrangements will not answer the question raised by Fiona Phillips – who watched both her parents succumb to Alzheimer's – as to why a person with terminal cancer does not have to pay for their own treatment while someone with a degenerative brain condition does.

Dealing with dementia is not just a matter of funding, however. It is also about the quality of care. Here, again, the lack of focus has much to answer for. Horror stories of patients either neglected, or rendered all-but insensible by a "chemical cosh" of anti-psychotic drugs, or confused and upset by being forced to live in deeply unsympathetic institutional environments, are more often the result of inadequate training than malice.

Not only are patients with Alzheimer's and similar conditions rarely accorded separate facilities in care homes and hospitals, but nursing and support staff receive little training in identifying their problems let alone responding to their needs. With a quarter of hospital beds filled by elderly patients suffering from dementia, and research suggesting that they both stay longer than those without the condition, and commonly leave in a worse state than when they arrived, the situation is wholly inexcusable.

What is required, then, is nothing short of a top-to-bottom overhaul of our approach to dementia. That means dedicated facilities for dealing with sufferers' complex needs, and automatic training for all health and social care professionals. Given that the Alzheimer's Society estimates that less than half of those with dementia have been diagnosed as such, attention must also be paid to ensuring that GPs know what to look out for. Meanwhile, more consideration must go into helping those affected to stay in their own homes for longer. A fresh look must be taken at how care is provided, and early efforts to make towns and cities more dementia-friendly must rapidly become the norm.

In fairness, progress has been made in raising awareness. But there must be action as well as talk. Although no less a figure than the Prime Minister recently warned of a "national crisis", and doubled the funding for research, dementia still receives far less than cancer, say, or heart disease. More pertinently, today's patients – and even tomorrow's – are unlikely see any benefit.

Dementia has been called the "thief of thought", its progress "death in slow motion". Sufferers, and their families, can no longer be allowed to slip through the gaps.