Free The Female Brain by Louann Md Brizendine

functions a little better. You’re clearer and you remember more. You think more quickly and more agilely. Then at ovulation, around day fourteen, progesterone starts squirting out of the ovaries and reversing the actions of estrogen, acting more like weed killer on those new connections in the hippocampus. During the last two weeks of the cycle, progesterone causes the brain to become first more sedated and gradually more irritable, less focused, and then a little slower. This may be one of the pivotal reasons for the change in stress sensitivity during the second half of the menstrual cycle. The extra connections built during the weeks that estrogen is on the rise are being reversed by progesterone in the last two weeks.
    In the last few days of the menstrual cycle, when progesterone collapses, this calming effect is abruptly withdrawn, leaving the brain momentarily upset, stressed, and irritable. This is where Shana was when she screamed at her mother. Many women say they cry more easily and often feel out of sorts, stressed, aggressive, negative, hostile, or even hopeless and depressed right before their periods begin. In my clinic we call them the “crying over dog food commercials” days, because even silly, sentimental things can trigger a tearful response during this short time. At first this abrupt mood change takes girls like Shana by surprise. Teens think that all they need to know about the menstrual cycle is to remember their Tampax and take Advil or Aleve for the cramps on the day the blood flow starts. The idea that even when they’re not bleeding there could be brain effects from their cycling hormones takes some getting used to. By adulthood, they know how to handle it. Most women know that, in weeks three and four, angry impulses fall under the two-day rule. They’ll wait two days and see if they still want to act on them.
    It took another few days for Shana to realize she should not have spoken to her mother the way she did. And as her progesterone cycled out and her estrogen came back up, her irritability began to wane. Connections were once again sprouting in the hippocampus, and her brain gears were greased and working to full capacity. Pretty soon she was surprising everyone with her wisecracks and smart-alecky remarks, and they were getting her into a bit of trouble—the boys just couldn’t keep up at times, and she was riding the edge with the girls. Brain performance in some females can fluctuate with the hormonal changes of the menstrual cycle. One of the most estrogen-sensitive parts of the brain—the hippocampus—is a major relay station for processing memories for words. This may be one biological reason behind women’s increased verbal performance during the highest estrogen week—week two—of their cycles. I often joke with my female grad students that they should take their oral exams on day twelve of their cycles, which is the peak of their verbal performance. Maybe the same should go for teen girls and the SATs—or for wives wanting to win a fight with their husbands.
    W HY THE T EEN G IRL B RAIN F REAKS
    Think about it. Your brain has been pretty stable. You’ve had a steady flow—or lack—of hormones for your entire life. One day you’re having tea parties with Mommy, the next day you’re calling her an asshole. And, as a teen girl, the last thing you want to do is create conflict. You used to feel like a nice girl, and now, out of nowhere, it’s as though you can’t rely on that personality anymore. Everything you thought you knew about yourself has suddenly come undone. It’s a huge gash in a girl’s self-esteem, but it’s a pretty simple chemical reaction, even for an adult woman. It makes a difference if you know what’s going on.
    The trouble for some women is caused by estrogen and progesterone withdrawal in the brain, which happens in the fourth week of the cycle. The hormones bottom out precipitously, and the brain begins yearning for their calming effects.