(Medical Xpress)—Women with Alzheimer's show worse mental deterioration than men with the disease, even when at the same stage of the condition, according to researchers from the University of Hertfordshire.

In the paper published in the Journal of Clinical and Experimental Neuropsychology, the researchers discovered that men with Alzheimer's consistently and significantly performed better than women with the disease across the five cognitive areas they examined. Most remarkably, the of women with Alzheimer's are worse when compared to men with the disease, which is a striking difference to the profile for the healthy population where females have a distinct advantage.

The researchers led by Professor Keith Laws completed a meta-analysis of neurocognitive data from fifteen published studies, which revealed a consistent male advantage on verbal and visuospatial tasks, and tests of both episodic1 and semantic2 memory.

Keith Laws, Professor of psychology, said: "Unlike associated with normal aging, something about Alzheimer's specifically disadvantages women.

"There has been some previous, but limited, evidence that females with Alzheimer's deteriorate faster than males in the earlier stages of the disease. And possible explanations are for a hormonal influence, possibly due to oestrogen loss in women or perhaps a greater cognitive reserve in males which provides protection against the disease process. But further studies to examine with the disease are needed to provide greater clarity on these issues."

Further analysis of the study data showed that age, and severity did not explain the advantage that men with the disease have over women with the disease.

Alzheimer's disease, a common progressive condition affecting memory, thinking, behaviour and emotion, is the most common form of dementia. Alzheimer's Disease International estimates that there are currently thirty million people in the world with dementia, with 4.6 million new cases every year. The incidence of Alzheimer's is greater among women than men, with the difference increasing with age.