Chicago ? A new study disputes the widely held notion that menopause makes women scatterbrained and forgetful.

Researchers conducted periodic memory tests on 803 menopausal women over two years and found to their surprise that their memories were just fine. In fact, the women’s scores improved slightly over time; the researchers were expecting a decline.

The researchers said if menopausal women are forgetful sometimes, it is probably not because of any harmful hormonal changes in the brain, but because they are busy, distracted and stressed-out dealing with the ordinary pressures of midlife.

“We are not saying that the forgetfulness is all in their heads,” said lead researcher Peter M. Meyer, a biostatistician at Rush University Medical Center in Chicago. “The question we were trying to answer was: Is this forgetfulness reflective of something bigger, below the surface,” such as the onset of mental decline?

Many women complain that they become more forgetful after menopause, and some doctors have come to believe that the hormonal changes brought on by menopause are the reason.

Naturally occurring estrogen is thought to help keep brain cells healthy, but it drops during menopause. In fact, the hormone supplement industry was built partly on the premise that estrogen pills could keep women’s minds sharp — an idea that has recently been challenged.

The new study appears in Tuesday’s issue of the journal Neurology.

“It may be that the brain does not need the hormones as much as we think,” Russel Thompson of the South Texas Veterans Health Care System wrote in an accompanying commentary.

Other research has suggested that midlife forgetfulness might be due to stresses such as children becoming teenagers and parents dying. Meyer said those stresses, rather than true mental decline, could account for what some women describe as memory loss.

Dr. Sam Gandy, a neurologist at Thomas Jefferson University, said the study is “reassuring in the short term” but does not settle whether the hormonal changes in menopause might hasten mental decline and lead to Alzheimer’s disease later on.

The brain processes involved in Alzheimer’s typically begin at least 10 years before symptoms occur, so the Chicago women would need to be followed longer to see if the early results hold up, said Gandy, a scientific adviser to the Alzheimer’s Assn.