top of page

Part One: Pre-Pregnancy: How women’s brain biology, hormones and mood relate!

Originally posted March 31, 2014.

Somatic Psychology combines the study of psychology, physiology, and emotion, bridging the gap between body and mind. So, understanding and managing your emotional responses are integrated with understanding and managing the health of your unseen brain and body biology through positive wellness choices.

Women’s mental and emotional health is complex. Three influences on mental health across a woman’s lifespan are: genetics (temperament and family heredity), reproductive and stress biology and life events.

Genetics: Innate temperament and family history

Innate temperament is a concept developed and researched by Alexander Thomas and Stella Chess. In the 1950’s, by studying infants and children across many years. They identified nine dimensions of temperament: activity (constant motion or less so), rhythmicity (internal biological schedule), initial reaction of approach or withdrawal in new situations, adaptability to change, intensity of emotion, general upbeat or downbeat mood, distractibility (tendency to be sidetracked), persistence and sensitivity to external stimuli.

Chess and Thomas also found that 65% of infants and babies are innately “easy” “difficult” or “slow to warm up.” Easy babies tend to have regular sleep and eating schedules, adapt to change easily and don’t fuss a lot. Difficult babies tend to have irregular sleeping and eating schedules, and fuss a lot. Slow to warm up babies withdraw from new experiences. Chess and Thomas found that these traits are stable throughout childhood.

These traits persist into adulthood, yet are modifiable through awareness, life experiences and training. But innate temperament is one influence on mental health.

A family history of mental illness, such as schizophrenia, bipolar disorder, major depressive disorder, generalized anxiety disorder is an indication that an individual might have a genetic predisposition to mental health issues.

The Estrogen-Serotonin Connection: The hormonal shifts of reproduction

Reproductive biology influences women’s monthly and overall life cycles. Fluctuating estrogen levels influence brain neurotransmitter levels which in turn, influence mood.

Open Feedback Loop of the Hypothalamus-Pituitary-Adrenal Cortex Axis (HPA Axis)

The Hypothalamus Pituitary Adrenal Axis (HPA), also known as the Limbic Hypothalamus Pituitary Adrenal Cortex Axis (LHPA) is our open feedback system for our stress response. In the past decade, with advanced brain imaging and targeted research, scientists’ understanding of the human neuroendocrinology system has progressed. Brain imaging has made it obvious that the brain’s emotional system, the limbic system, interacts with glands via hormones and neurotransmitters!

In addition, keep in mind the limbic system is an open feedback loop. We continuously gather information from our perception of the external world, feed into our internal emotional system and then react based on our interpretation of those perceptions.

The hypothalamus is part of the limbic system, which is also known as the emotional brain or mid-brain. The hypothalamus releases serotonin and cortisol-releasing hormone (CRH) which prompts an emotional call to action! How so? The brain and glands use hormones and neurotransmitters to talk to each other!

The hypothalamus releases serotonin and cortisol-releasing hormone (CRH) which prompts the pituitary gland to release adrenocorticotropic hormone (ACTH) which prompts the adrenal glands to secrete levels of cortisol and adrenaline into the bloodstream which finally prompts us to be either way chill, stressed out or somewhere in between!

And all these steps take just a split second to occur! So if you’re relaxing with a pina colada by the pool and suddenly need to run from the wild boar, well, the HPA sends you on your way pronto!

Again, this interaction among the hypothalamus, pituitary and adrenal cortex system is called the HPA axis. The HPA axis is in a continuous open feedback loop, interacting with perceived safety and threats. Our emotions and physical reactions ebbing and flowing with this open feedback loop.

Now, let’s talk about serotonin. Remember, the hypothalamus greases the pituitary gland with serotonin!

Serotonin is involved with mood. Decreased serotonin levels are associated with depression, anxiety, aggression, sleep disruption, and irritability.

The precursor to serotonin is, guess what, estrogen!

So estrogen is powerhousing the availability of serotonin, the mood hormone, which, in turn, greases our brain-bio loop, the HPA axis, and affects how we feel!

Next, let’s look at how much the availability of estrogen fluctuates during a woman’s reproductive cycle.

Ovarian-Hypothalamus-Pituitary Feedback Loop: Menstruation and hormonal shifts

A woman’s estrogen levels fluctuate weekly, with the menstrual cycle.

The human menstrual cycle is about 28 days. Day 1 is counted from the first day of bleeding and it lasts to day 1 of the next time of bleeding.

Estrogen (and progesterone) is secreted by the ovaries.

Estrogen rises throughout the first two weeks of the menstrual cycle. High estrogen levels mean high serotonin levels. So all’s right with the world during these weeks.

But then estrogen falls sharply around day 14, in the first half of week 3, in preparation for ovulation. It then rises again for the second half of week 3.

But when you are fully into premenstrual week 4, estrogen levels fall all week long until it reaches the lowest level, at the end of your cycle.

Premenstrual syndrome is a result of the shifting hormonal and neurotransmitter levels as women cycle through their reproductive cycle.

The feedback loop of the ovaries- hypothalamus-and-pituitary is essential for the normal physiology of the female reproductive cycle.

To sum up, the brain and the glands of the O-HPA axis use hormones and neurotransmitters to communicate to each other and which affects our emotions in milliseconds! The higher components of the axis, the hypothalamus and the pituitary to modulate their secretions in feedback to the secretions of the ovaries.

Serotonin, one of the kick-off hormones of the HPA axis, is produced in the hypothalamus, which is a part of the emotional brain center, and affects mood: anger, depression and anxiety.

The precursor to serotonin, produced in the hypothalamus, is estrogen, which is produced in the ovaries.

And estrogen fluctuates with our menstrual cycle! So, women’s hormonal cycles are directly related to the chemistry of the emotional brain and the stress feedback loop.

Now let’s look at the enormous hormonal changes pregnancy, birth and postpartum bring to emotional brain chemistry!

In Part Two, we’ll look at the enormous hormonal changes pregnancy, birth and postpartum bring to emotional brain chemistry!

bottom of page