Birth control pill affects memory

Taking the contraceptive pill can affect how a woman remembers things, research suggests.

A study found that women using oral contraception were better at remembering the emotional aspects of an event, while women not using it were better at remembering the specific details.

The researchers were quick to point out the study findings did not show that the pill damages memory, just that it appeared to change the type of information that women retained in their memory.

"What's most exciting about this study is that it shows the use of hormonal contraception alters memory," said Shawn Nielsen, a researcher at the University of California, Irvine.

"There are only a handful of studies examining the cognitive effects of the pill, and more than 100 million women use it worldwide," she added.

The study looked at how groups of women on the contraceptive remembered what they saw in photographs of a car accident involving a mother and son, and compared their recollections of the event with those of women experiencing natural hormonal cycles.

Women using hormonal contraceptives for as little as one month remembered more clearly the main steps in the traumatic event - that there had been an accident, that the boy had been rushed to the hospital, that doctors worked to save his life and successfully reattached both his feet, for instance.

Women not using them remembered more details, such as a fire hydrant next to the car.

The changes in memory made sense, the said Neilsen and neurobiologist Larry Cahill, because contraceptives suppress sex hormones such as oestrogen and progesterone to prevent pregnancy. Research by the same group had previously linked these hormones to women's strong "left brain" memory.

The findings could help lead to fuller answers about why women experience post traumatic stress syndrome more frequently than men, and how men remember differently than women.

Pauline Maki, professor of psychiatry and psychology at the University of Illinois at Chicago, who specializes in memory and brain functioning, said:

"The fact that women on oral contraceptives remembered different elements of a story tells us that oestrogen has an influence on how women remember emotional events."

The study is published in the journal Neurobiology of Learning and Memory.

This article was published on Mon 12 September 2011