Your period really does cause changes in your brain that lead to mood swings, research shows

In women, certain times of the month can be marked by intense irritability, mood swings and food cravings.

Research shows that you really can blame your period for feeling lousy.

New research shows that changes occur in brain function and structure in women with severe forms of premenstrual syndrome, also known as PMS.

Louise Stiernman, a doctoral student at Umeå University in Sweden, conducted several studies among women with premenstrual dysphoric disorder (PMDD), a form of severe PMS.

Brain scans of women taken at different times of the month have shown that women with severe PMS show unique changes in areas associated with emotion during their periods.

Using MRI scans, she tracked activity in different parts of the brain during different times of the month.

Analysis showed that women with PMDD have increased activity in brain areas associated with judging the emotional meaning of things.

This area is also important for coordinating appropriate behavioral responses.

The pattern was clearly visible just before menstruation, the period that refers to about a week before a woman’s period begins.

Research has also shown that the thickness of the cerebral cortex is thinner in women with PMDD, suggesting that the effects on the brain last longer.

Up to a third of women in the UK suffer from PMS, a condition that can involve feelings of depression, irritability, bloating and anxiety during menstruation, as well as tender breasts and blotchy skin.

Ms Stiernman said it is possible that underlying differences in brain structure and function in women with PMDD make them more vulnerable to experiencing serious mood symptoms.

“The results bring us closer to a biological explanation for why women with severe PMS are more sensitive to strong emotional reactions to things in their environment during the premenstrual phase,” the researcher said.

She added that the findings do not clarify cause and effect, and that it is possible that recurring PMS symptoms affect the makeup and functioning of the brain.

It is estimated that as many as 30 percent of women in the UK suffer from moderate to severe PMS, while 5-8 percent suffer from PMDD.

Symptoms may include depressed mood, hopelessness, mood swings, sudden crying spells, increased irritability and anger.

Ms. Stiernman’s findings are presented in her dissertation.