Psychoneuroendocrinology

Psychoneuroendocrinology is the clinical study of hormone fluctuations and their relationship to human behavior. It may be viewed from the perspective of psychiatry, where in certain mood disorders, there are associated neuroendocrine or hormonal changes affecting the brain. It may also be viewed from the perspective of endocrinology, where certain endocrine disorders can be associated with psychiatric illness. Brain dysfunctions such as in the hypothalamus can affect the endocrine system, which in turn can result in psychiatric symptoms. This complex blend of psychiatry, neurology and endocrinology is needed to comprehensively understand and treat psychiatric illnesses (see neurobiological brain disorder).

Premenstrual syndrome is a mood disorder which occurs recurrently in the late luteal phase of the menstrual cycle and remits within the first day or two after the onset of menstruation. Symptoms include depression, irritability, anxiety, insomnia, bloating, breast tenderness, cramping, and headaches. About 5-9% of women of child-bearing age meet the DSM-IV criteria for PMDD. In some women, end-of-cycle worsening actually represents "menstrual magnification" of an underlying mood disorder.

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