Women have long claimed their monthly period makes them more irritable or stressed.

Now, however, scientists have said the idea that a woman’s menstrual cycle affects her thinking is nothing more than a myth.

According to some previous studies, women are more impulsive and moody before their period, and more ‘rational’ afterwards.

Scientists have said the idea that a woman’s menstrual cycle affects her thinking is nothing more than a myth

But the latest research says that while women may feel their thinking became altered, this was not the case when studied scientifically.

It seems that despite hormone levels fluctuating enormously in a woman’s body, they have no effect on her ability to remember or make decisions. The findings suggest that the cause of the problems may actually lie elsewhere.

Professor Brigitte Leeners and her team examined three aspects of mental abilities over two menstrual cycles.

They concluded that the levels of the hormones oestrogen, progesterone and testosterone had no impact on working memory, which is the ability to remember facts while completing a task.

Nor did it have any effect on cognitive bias, the likelihood that thinking would be skewed one way or another. And women were just as able to pay attention to two things at once, the researchers found.

The authors said none of the hormones had any replicable, consistent effect on thinking.

According to some previous studies, women are more impulsive and moody before their period, and more ‘rational’ afterwards

Professor Leeners said: ‘As a specialist in reproductive medicine and a psychotherapist, I deal with many women who have the impression that the menstrual cycle influences their well-being and cognitive performance.’

She wondered whether if this anecdotal evidence could be scientifically proven, and attempted to shed some light on the controversial topic.

The team, from the Hanover Medical School and University Hospital Zurich, monitored 68 women.

Analysis of the results from the first cycle suggested that cognitive bias and attention were affected, but these results weren’t replicated in the second cycle.

The team looked for differences in performance between individuals and changes in individuals’ performance over time, and found none.

Professor Leeners said: ‘The hormonal changes related to the menstrual cycle do not show any association with cognitive performance.

'Although there might be individual exceptions, women’s cognitive performance is in general not disturbed by hormonal changes occurring with the menstrual cycle.’

She said further work on larger samples was needed to offer a fuller picture of the way that the menstrual cycle affects the brain.

Other research has found that women often blame feelings of stress on their period – but at other times of the month the complaints are attributed to other causes, such as physical exertion, psychological distress or even the weather.

The research was published in the journal Frontiers in Behavioural Neuroscience.