Major discrepancies in the availability of treatments for Alzheimer's disease are robbing many victims of the chance to live independent lives.

The postcode prescribing of anti-dementia drugs was supposed to have been outlawed by the government's medicines watchdog, Nice (National Institute of Clinical Excellence) last year.

But surveys have revealed that health authorities who were poor prescribers of drugs before that date have remained so. West Midlands, Shropshire and Hertfordshire have all been named as having poor records in making treatments available.

Three drugs - Aricept, Exelon and Reminyl - have been approved for use in this country in recent years. All act by blocking the action of the brain chemical cholinesterase and help to stabilise patients' symptoms. Individuals can start to watch TV again and hold conversations.

'These drugs are the best treatments we have and can delay Alzheimer's progression for up to a year or more,' said Richard Harvey, research director of the Alzheimer's Society. 'That can make an awful lot of difference to patients, and to the people who have to look after them. They feel more independent and more in control of their lives.'

However, until last January, these drugs - which cost about £1,000 a year per patient - were difficult to obtain. Then Nice stepped in and approved their use in the UK.

'Unfortunately, many health authorities do not have the money to supply Alzheimer's drugs,' said Julia Cream of the Alzheimer's Society. 'Those that originally had a bad record for supplying drugs continued to limit supplies.'

In the West Midlands, patients can only obtain treatments by enrolling in drug trials - which means they have a 50 per cent chance of being given a placebo. By contrast, Alzheimer's patients in Cambridge have little problem in obtaining the drugs.