Experiencing periods of moodiness is part of life. Women don’t have the corner on mood swings (although they often get as if they do!). The tortured artist, the brooding musician, or the poet are all common images of moody people, usually men; stereotypes often portray them in a positive or redeeming way.

In contrast, women with PMS are unpredictable, unprovoked, out of line. The media often portrays these women as Dr. Jekyll Hyde, veering from nice to nasty at the drop of a dime. Knowing happens in your body will help you understand your emotions, why they so often seem uncontrollable during the premenstrual phase.

Moods and Your Body

Moods aren't just mental or emotional states; they create physical changes or responses in the body. Studies have also shown that emotions can affect the immune system.

• Fear causes heightened heartbeat, increased muscle tension, and an increased flinch response.

• Anger causes effects similar to fear, including heightened heartbeat and increased muscle tension.

• Sadness causes tightness in the eyes and throat and relaxation in the arms and legs.

Fluctuating Hormones, Fluctuating Moods?

Your periods can govern your moods, since the hormonal yo-yoing of the menstrual cycle has a demonstrated effect on emotions. Studies have shown, for example, that the hormones estrogen and progesterone intensify undesirable emotions, such as sadness, anxiety, and irritability in women with PMS. Other research suggests that some women are able to stabilize their mood swings even as their bodies are undergoing major hormonal shifts.

In addition, both perimenopausal and menopausal women can be treated with estrogen replacement therapy to reduce their mood symptoms, which illustrates the intimate relationship between hormones and mood. However, it's not yet clear why hormones cause mood swings, depression, irritability, or tension and why some women, like the ones in Dr. Silbersweig's study, are immune to these fluctuations.

The Female Brain

Scientists have devoted more time and money in the last to gender-based brain research to discover how men and women’s brains operate. Researchers are also looking at what happens brains during their menstrual cycle. One of the things that discovering is that there may be such a thing as the “female brain.” example, neuropsychiatrist Louann Brizendine, of San Francisco’s Porter Psychiatric Institute, argues that there are certain neurological reasons for women’s behavior. She suggests that when hormones as cortisol, estrogen, and dopamine flood a woman’s brain, the becomes more stressed by emotional conflict compared to men.

Estrogen’s Impact

Estrogen has multiple effects on the body and the brain: (1) stabilizes mood; (2) it protects the heart from heart disease by reducing the body’s total cholesterol level, while raising HDL or “good” cholesterol levels and lowering LDL or “bad” cholesterol levels; (3) protects bones by preventing the release of calcium from bones into the bloodstream; and (4) it even prevents memory loss. Many of the mechanisms involved are interrelated, which makes it extremely difficult to link a single process to a given effect. Estrogen’s other effects on the body include:

• Maintaining tissue elasticity

• Helping maintain vision (preventing cataracts and dry eyes, for example)

• Impacting the immune system by reducing the body’s inflammatory response and increasing the production of antibodies that destroy bacteria and viruses

• Affecting the body’s metabolism by impacting how carbohydrates and fats are metabolized

• Preventing vaginal atrophy

Estrogen has a cascade of effects on the brain and nervous system. For example, estrogen shares brain receptors with serotonin, which may explain why some women feel confused or foggy during PMS. It also binds the thyroid hormone, which means it influences the body’s metabolism. Estrogen’s effects on brain chemicals include:

• Increasing norepinephrine (involved in alertness, concentration, aggression)

• Decreasing dopamine (regulates movement, emotion, and mood)

• Having multiple effects on serotonin (affects emotions, behavior, and thought)

• Affecting blood tryptophan levels (the amino acid from which serotonin is made)

• Increasing endorphin levels in the brain and bloodstream (the body's natural painkillers)

• Protecting the acetylcholine systems (chemicals involved in cognition, motivation, attention)

• Having a complex relationship with DHEA (a neurosteroid with mood effects)

However, simply because estrogen's effects are demonstrable doesn't mean they're well understood. For example, although low estrogen levels are linked to depression, increasing estrogen will not necessarily cure depression. Hormone therapies, such as prescribing birth control pills to reduce PMS symptoms, may help some women, but researchers are not able to explain why they cannot help others.