NEARLY half the people being given the Alzheimer drug Aricept in an informal trial in the Glasgow area have shown a significant response, the doctor in charge of the programme said yesterday.

The patients who have taken part in the evaluation were chosen according to strict diagnostic criteria, and the benefits are only temporary, said Dr Donald Lyons, a consultant with Greater Glasgow Community and Mental Health Trust.

However, his findings, presented at a major dementia conference, have raised hopes that expensive drugs such as Aricept - and a second drug of the same type launched last week - will become more widely available for Alzheimer patients.

Provision has been patchy across the UK because of doubts by health authorities about their cost and effectiveness. The price of Aricept to the NHS is #68 or #95 a month, depending on dosage.

The drug has been heavily advertised in the medical press and has attracted private prescriptions from those who can afford them.

So far, Greater Glasgow Health Board, which is funding the evaluation, has given approval for 40 patients to be given the drug, and more than 30 have been tried on it.

''It does a good deal for some and for others it does very little,'' said Dr Lyons. ''If there is no benefit after three months they are taken off.''

A few were taken off right away because of side effects, and slightly less than half showed significant improvement, he said.

The benefits, which are assessed at memory clinics and by the observations of carers, last for an average of about six months before the disease resumes its course. There is no evidence that it works in severe forms of the disease.

The conference, held in Glasgow by Alzheimer Scotland-Action on Dementia to mark the start of Dementia Awareness Week, also heard a plea for improved assessment of elderly drivers who might be suffering from dementia.

With nearly 2,000,000 of the UK's 32,000,000 driving licence-holders already more than 70 years of age, the problem was bound to grow with the increased elderly population, said Dr Neil Gillespie, a lecturer and senior registrar in ageing and health at Ninewells Hospital, in Dundee.

Studies in Scandinavia had shown that 30% to 40% of elderly drivers killed in road accidents had some degree of Alzheimer's.