Dementia patients are being 'cast aside' by the NHS and treated like second-class citizens, the head of Alzheimer's Society has warned.

Michelle Dyson accused ministers of ignoring Britain's biggest killer and said patients were too often diagnosed, discharged and sent home with little more than a leaflet.

In a damning intervention, she said dementia was still not treated with the same urgency as cancer or heart disease, despite devastating families and placing huge pressure on hospitals and care homes.

The charity chief said the NHS was woefully unprepared to deliver emerging Alzheimer's drugs, comparing the impending tragedy to watching a 'car crash in slow motion'.

Ms Dyson, chief executive of Alzheimer's Society and a former senior official in the Department of Health and Social Care, said: 'Imagine being told you have a disease that will rob you of your memory, your independence and your ability to recognise the people you love – and then being sent home with a leaflet.

'That would be unthinkable for cancer. Yet for dementia, it happens all the time.

'A leaflet is not care or treatment. It doesn't help a frightened husband, wife or daughter when the person they love starts to disappear in front of them.'

Ms Dyson said dementia was 'not part of the conversation at all' in government, even though a million people are living with the disease.

She said science showed that dementia had the 'hallmarks of a disease', which can be prevented in some cases, diagnosed and treated. 

Up to 45 per cent of dementias are preventable, with 14 modifiable risk factors including smoking, alcohol, obesity, blood pressure and hearing loss.

But she said ministers were failing to run a public health campaign that could warn millions how to cut their risk, adding that only 5 per cent of British patients had access to proper biomarker testing, compared with 30 per cent in Italy and 20 per cent in Spain.

Ms Dyson said: 'The NHS is meant to be there for everyone who needs it but people with dementia are being cast aside and left to fend for themselves.

'People with dementia are not asking for special treatment. They are asking to be taken as seriously – and with the same urgency and compassion – that we rightly expect for cancer and heart disease.'

Asked if she was suggesting dementia patients were treated as second-class citizens, Ms Dyson replied: 'Absolutely.'

The Daily Mail and Alzheimer's Society have partnered in a drive to defeat dementia, which claims 76,000 lives a year. The Defeating Dementia campaign aims to raise awareness of the disease, in an effort to increase early diagnosis, boost research and improve care.

Ms Dyson said urgent change was needed because many dementia patients faced a brutal experience that entailed a long wait for a diagnosis, only to be discharged from specialist care immediately afterwards.

A scathing report last month revealed that waiting times for diagnoses are continuing to increase as 'deeply concerning' delays become routine.

Patients waited an average 137 days from referral to diagnosis last year, according to the latest audit of memory assessment services. This is five days longer than when the Royal College of Psychiatrists' audit was last published just two years ago. Almost half of dementia clinics have an 18 weeks or less average wait time but one in eight make patients wait more than a year.

'Dementia is where cancer was a few decades ago,' Ms Dyson said. 'We need the same national mission, the same targets, the same urgency and the same refusal to accept late diagnosis and poor care as inevitable.

'If cancer patients were diagnosed late, discharged with a leaflet and told to come back when things became unbearable, there would be outrage. People with dementia deserve that same outrage.'

She said: 'The Government does not take dementia seriously at all. The next Prime Minister and Health Secretary must make dementia a national priority from day one.

'If ministers can find the will to transform cancer care, they can find the will to transform dementia care.

'We are watching a car crash in slow motion. The science is moving, drugs are coming, but the NHS is not ready.'

The Department of Health said: 'Dementia has a devastating impact on people living with the condition and on the families who care for them. We want everyone affected to be able to access high-quality, personalised support.'