Honoring the women without whom none of us would be here-- namely, our mothers! -- we caught up with Claudia Aguirre, PhD, a Los Angeles-based neuroscientist who has researched the role of female hormones in the brain and skin, to get a little science on a woman's hormones, and cutting through the myths that surround motherhood.

An Interview with Dr. Claudia Aguirre:

Essio: For centuries, women have been dismissed as "hormonal", especially if the moon happens to be full. What are the actual effects of estrogen on mood?

Dr. Aguirre: I wish this was all science fiction, but it’s not. Our hormones control us in many ways, including mood. Most people like to talk about estrogen, but there are many hormones at play when it comes to mood. Firstly let’s define the word ‘estrogen’: This is misleading as the word “estrogen” really refers to a family of hormones. The most abundant estrogen in adulthood is called Estradiol. Equally important is the role of Progesterone in women’s health. For simplicity’s sake, we’ll just say that a number of different sex hormones impact the brain’s region that controls our mood, called the amygdala, in such a way as to change our mood in a very cyclical manner, like the tides. In fact, the prevalence of mood disorders in women is approximately twice that of men, showing how intimately linked female hormones are with mood. Moreover, depressive disorders, which are also twice as common in women as in men, often occur in periods such as pregnancy, postpartum and at the beginning of menopause, when hormones almost feel out of control!

Essio: How does the body's natural hormonal "cocktail" change from PMS to pregnancy and post-partum, to menopause?

Dr. Aguirre: Now I’m radically oversimplifying here, but in all these “phases”, sex hormones are in a state of flux, or even imbalance. Elevated hormone levels suddenly appear in puberty, altering the chemicals in the brain, as well as those coursing through our veins. For years, the constant flux of estradiol and progesterone carries with it fluctuations in bodily secretions, appetite, sleep and mood.Approximately 20% of women experience premenstrual syndrome (PMS), or premenstrual dysphoric disorder (PMDD), a more severe form of PMS. Scientists believe that a woman’s progesterone level, coupled with how her brain’s amygdala responds to emotional stimuli, is at the heart of PMDD. During pregnancy, hormones are at an all-time high to support the growth and development of a whole new human being inside! Post-partum depression occurs in some women, and there seems to be a link to a hormonal imbalance already in place that intensifies after giving birth. Finally there is peri-menopause (which could take up to a decade) and menopause (the period where the ovaries have halted production of sex steroid hormones). During this transition, estradiol and progesterone decline with age, effecting many changes in a woman’s body – from her physique, to her mood, to her general health. But since a typical woman goes through these phases of ‘hormonal imbalance’ for the large part of her life, maybe we should consider the flux state as ‘normal’ rather than trying desperately to regain the balance of childhood!

Essio: America is sleep-deprived, period. New mothers in particular experience disrupted sleep because they're nursing and caring for the new baby, and insomnia tops the list of complaints among women in perimenopause and menopause. What advice do you have for inviting sleep, and for dealing with the fatigue of sleep-deprivation?

Dr. Aguirre: True, expectant and new mothers suffer from sleep disruption, but it’s not all to do with nursing. Our friends, the hormones, again play a big role here. During pregnancy, elevated hormones alter the brain’s chemistry, affecting our circadian rhythm and sleep. In fact, according to the 1998 National Sleep Foundation poll, 78% of women reported more disturbed sleep during pregnancy than at other times. Interestingly, the neurohormone Melatonin is also affected by pregnancy, suggesting a link between female hormones and our internal clock. Since melatonin levels are also altered with depressive states, we can see that mood, sleep and female hormone flux are all intimately connected. This is complicated and scientists are still trying to untangle many of these complexities, but there is no need to lose sleep over it! Here are some tips to help you sleep, even when your hormones are keeping you awake:

• Get some sunshine – the light will keep your circadian rhythm in check
• Exercise – this boosts circulation and keeps you energized during the day, while helping you fall asleep
• Take a nap – get your zzz’s when you can, even if it’s during the day
• Drink plenty of fluids – but tone it down before bedtime to avoid getting up at night
• Avoid heartburn – skip the spicy, acidic or fried meal to sleep better
• Get comfortable – support your growing bump with a pillow or bolster
• Calming scents – Essential oils are to be avoided during your first trimester. After consulting with your doctor, some essential oils like lavender and ylang ylang can help calm, relax and aid sleep.

What’s more, the more sleep you get, the less likely you are to suffer from post-partum depression.