5 Ways Your Hormones Are Affecting Your Brain: The Menstrual Cycle, Anxiety, Memory, Exhaustion and Chocolate

Friday, April 11, 2014 by Meg   •   Filed under Physical Health and Emotion

The only reason I'm able to post this is because I'm extremely caffeinated. Coffee or no, if someone doesn't give me some chocolate soon, I may lose my shit.

Maybe it's not that bad, but we've all had those days. Oddly, their appearance may not be related to chocolate withdrawal. Hormones play an important role in the way we perceive the environment. The hormones related to menstrual cycling can alter everything from sleep, to obsessive thoughts, to motivation and even the susceptibility to addictive substances.

Addictive substances...like chocolate right?

Here's an overview.

Simplified Phases of the Menstrual Cycle:


  • Estrogen levels begin to climb
  • Lasts around 2 weeks from period start to ovulation


  • Egg is released


  • High hormone levels including progesterone and estrogen 
  • Lasts around 2 weeks, from ovulation to period start

The hormones released during these phases may influence things like memory and anxiety. Estrogen, in particular, has been linked to the amygdala (stress responder) and the hippocampus (memory center) throughout the cycle7. The hormonal changes may also affect glucose and other systems in the body and indirectly lead to unwanted symptoms.

So, what kinds of symptoms are we looking at?

1. Hormones and Intrusive Thoughts 

Intrusive or scary thoughts can trigger a great deal of anxiety responses. However, they may be at their worst at certain times of the month, when hormonal changes lead to higher levels of arousal. 

In one study, women were exposed to disturbing film clips which depicted violence against people or animals1. Their hormonal levels were taken, and at a later date, recollection of the film details, and patterns of intrusive thoughts surrounding them, were measured. According to researchers, women in the luteal phase of their menstrual cycle were more able to remember details of the videos and experienced more intrusive thoughts related to them. This may be due to the increased arousal levels present in this phase. 

In other words, if you're already a little anxious because naturally high hormones are poking at your amygdala, you might see the world as slightly more dangerous and your brain pays more attention to any stressors you might experience. This is consistent with other studies that show women are more responsive to stress overall during their luteal phase2.

The researchers with the disturbing film clips noted that this may have implications for issues such as post traumatic stress disorder, as anecdotal evidence has suggested that women in certain cycle phases are more prone to developing these disorders1. This may have even more implications in relation to birth trauma or postpartum depression, both of which involve intrusive thought patterns and hormonal fluctuation. 

2. Hormone Shifts and Memory

"I'm sorry, I can't remember what I called you for. It was probably to pick up chocolate."

High emotion--which may include the intrusive thoughts discussed above--can overwhelm thinking or working memory systems, according to Daniel Goleman, author of Emotional Intelligence11. Goleman reports that because the prefrontal cortex is responsible for emotional regulation and working memory, higher anxiety may have the ability to override some memory functions or thoughts about task completion. 

But at lower levels of stress, hormonal fluctuations may influence memory just as much as emotional input. And the news isn't all bad. 

Other studies on memory encoding systems found that women in luteal phases had more ability to recall peripheral details of a story--those details around the central theme--when compared with men or women in follicular phases. While all groups had similar attention spans during the tests, women in luteal phases had better recall of the surrounding details one week later, suggesting that the transfer into long-term memory worked better3.

So, high hormones with a side of anxiety and improved memory? Sweet. 

Except, not all memory, and not all the way across the cycle. While memory for story details may increase in the luteal phase, research indicates that estrogen may negatively influence visual priming, or the way we process and store visual cues4. Less visual priming may mean it's harder to remember where you saw your shoes, particularly if they were moved by someone other than yourself.

"Coffee stain on the couch? I've never seen that coffee stain before in my life!"

However, this same study found that estrogen may help to increase verbal memory4. While this study did not find differences in mood across cycle phases, they found that the luteal phase corresponded to improvements in implicit memory tasks, like how to make pasta or typing on a keyboard without looking at each key. This study also found that women in their luteal phase had enhanced ability to recall verbal types of memories.

"Don't tell me you didn't say that. I remember. I was in my luteal phase."

Other studies have confirmed these links by reporting significantly lower error rates in working memory--or short-term memory--in women in their luteal phase5.

Of course this is the bright side. The flip side is that in the follicular phase, these verbal  memory processes may not work quite as well.  

Don't tell my husband.

Okay, so hormones are helping us remember some things while potentially making us a little more anxious, and impairing long-term memory at other times.  Great. That's it right?

3. Reward Centers at "That Time of the Month"

As if changes in memory wasn't enough, according to a press release from the National Institute of Mental Health, a woman's  menstrual cycle may affect the parts of the brain related to rewards and punishments7. According to researchers, pre-ovulatory women (or those in the follicular phase) had more response in the pleasure centers of the brain when getting rewards than their luteal phase counterparts. Researcher Karen Berman reports that this may be why women tend to be more susceptible to addictive drugs during the follicular phase of their cycles. Researchers noted that those in the luteal phase may have had less reward activation due to the progesterone present during that period. 

Is chocolate an addictive drug? If so, I'm screwed.


4. Hormones, Willpower and Glucose

Another theory, illustrated in Willpower by author Dr. Roy Baumeister, goes that fluctuations in glucose over the menstrual cycle may influence impulsivity and self-control8. According to Baumeister, glucose is a necessary part of the pathways involved in self-control. However, glucose is also necessary for female reproduction, and your body only has so much. So, during certain menstrual phases, when glucose is being used on reproductive facilities, self-control decreases and impulsivity may increase. This may be another explanation for the changes in reward systems noted by Dr. Berman7
"Bring on the chocolate, baby. I hear it's normal."

Fluctuations in glucose systems may also occur with other bodily imbalances, including thyroid issues or adrenal fatigue. Those with a history of these conditions may be even more prone to strong fluctuations, intrusive thought patterns, emotional disturbances and impulsivity. Imbalances across the HPA axis, another link to these systems that is involved in depressive response, can also trigger these symptoms9. This may be particularly true if the system is already out of whack due to less than ideal lifestyle choices.   

5. Cycle Induced Sleepiness

The changes in this circuitry may be part of the reason that women report disturbed sleep at some points in their cycles. According to researchers, bodily temperature fluctuations, thyroid changes, and changes in melatonin secretion may affect internal body clocks, also known as the circadian rhythm6. This can lead to increased sleepiness during the day, particularly in the luteal phase. 

I assume this means coffee can be considered drug therapy.

Okay, so our monthly hormonal cycles should be categorized like this:


  • Estrogen begins to climb
  • Decreased visual priming memory functions
  • Lower implicit memory (automatic memory)
  • Heightened reward processing
  • More susceptibility to addictive drugs


  • Egg is released


  • High hormone levels (progesterone and estrogen)
  • Improved verbal memory
  • Improved implicit memory
  • Increased daytime sleepiness
  • Increased arousal/anxiety
  • More susceptibility to intrusive or scary thoughts
  • Improved transfer of details into long-term memory

Described another way:


"Don't ask me if I've ever seen those socks before, I may do a lot for a back rub if you frame it like a reward, it's possible that I will forget how to make my famous pasta sauce, and for fuck's sake don't offer me cocaine (or ice cream) unless you want to lose the entire stash."


"Give me more coffee before I pass out at the breakfast table, don't say things you will hope I won't remember, offer me stronger rewards if you expect me to do ANYTHING, and prepare for the onslaught of nervous energy....and no, I'm not into the scary movies tonight."

While some of us might feel like this sometimes, there is no evidence that negative mood or stereotypical "bitchiness" is a universal experience10. What these studies suggest is that our memory may fluctuate a little, our arousal levels may peak in response to hormones (which may or may not be obvious), we may be a little more tired sometimes, and we may make an extra cup of coffee, or possibly start smoking crack. 

Hopefully not that last one. 

Fluctuations may be more subtle, but for some, they make a difference in anxiety and in functioning. If you understand how hormonal changes may affect you, it might be easier to plan your time accordingly. Nothing says "freak out" like planning a highly stressful event right before your period, at least in this house. 

Who am I kidding? I just hate hosting parties, but if it saves me from having to sweep, I'm going with it.

Related Posts:

  1. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3126908/
  2. http://www.ncbi.nlm.nih.gov/pubmed/19834266
  3. http://www.ncbi.nlm.nih.gov/pubmed/23891713
  4. http://www.ncbi.nlm.nih.gov/pubmed/11749982
  5. http://www.ncbi.nlm.nih.gov/pubmed/18544886
  6. http://www.ncbi.nlm.nih.gov/pubmed/11094139
  7. http://www.nih.gov/news/pr/feb2007/nimh-02.htm
  8. http://www.amazon.com/Willpower-Rediscovering-Greatest-Human-Strength/dp/0143122231
  9. http://brn.sagepub.com/content/8/3/210.short
  10. http://www.ncbi.nlm.nih.gov/pubmed/23036262
  11. http://www.amazon.com/Emotional-Intelligence-Matter-More-Than/dp/055338371X/ref=sr_1_1?s=books&ie=UTF8&qid=1387819148&sr=1-1&keywords=emotional+intelligence 

Topic-Relevant Resources

Insight into the effect of glucose and reward processing and why we crave chocolate.

Emotional Intelligence (why it can matter more than IQ)
Studies on emotional function, social prowess and their influence on success

Salt Sugar Fat: How the Food Giants Hooked Us
An in depth look at how the food industry alters physical and emotional health through advertising and addictive substances.

Everything you ever wanted to know about the connections between your vagina and your brain. It's worth the read.

When Panic Attacks
Detailed overview of cognitive behavioral techniques for changing negative thought patterns