For women, certain periods of the month may be characterized by intense irritability, mood swings, and food cravings.
Now, a study shows that you can actually blame your period for feeling sick.
New research indicates that there are changes in brain function and structure in women who suffer from severe cases of premenstrual syndrome, also known as PMS.
Louise Stiernman, a PhD student at Umeå University in Sweden, conducted several studies with women with premenstrual dysphoric disorder (PMDD), which is a severe form of PMS.
Brain scans of women taken at different times of the month have revealed that those with severe PMS have unique changes in areas involved with emotion during their period.
He used MRI scans to track activity in different parts of the brain at different times of the month.
The analysis revealed that women with PMDD had greater activity in parts of the brain related to evaluating the emotional significance of things.
This region is also important for coordinating appropriate behavioral responses.
The pattern was evident just before menstruation (period refers to about a week before a woman’s period begins).
Research also showed that the thickness of a part of the brain called the cerebral cortex was thinner in women with PMDD, indicating longer-lasting effects on the brain.
Up to a third of women in the UK suffer from PMS, which can involve feeling depressed, irritable, bloated and anxious during their period, as well as having tender breasts and blotchy skin.
Ms Stiernman said it’s possible that underlying differences in brain structure and function in women with PMDD may make them more vulnerable to experiencing severe mood symptoms.
“The results bring us closer to a biological explanation for why women with severe PMS are more likely to have strong emotional reactions to things in their environment during the premenstrual phase,” she said.
She added that the findings do not clarify what is cause and what is effect, and it could be that the recurrent symptoms of PMS are what affect the composition and function of the brain.
It is estimated that up to 30 per cent of women in the UK suffer from moderate to severe PMS, while between 5 and 8 per cent have PMDD.
Symptoms may include depressed mood, hopelessness, mood swings, sudden crying, increased irritability and anger.
Ms. Stiernman’s findings are presented in her doctoral dissertation.