Many women appear to be affected by symptoms of the premenstrual syndrome. However, to date, very little scientific knowledge has been accumulated surrounding this disease process. The focal point of this project is to determine whether or not the women with symptoms of the premenstrual syndrome have identifiable biochemical differences from women who do not have symptoms. The long term objectives include the application of this data in the formulation of therapeutic plans. The project is divided into four parts: 1) The identification of the patient population will differentiate those women who qualify as subjects from those who will be included in the control population. Detailed daily symptomatology questionnaires will be filled out over three cycles to delineate these groups. In addition, psychological tests will be performed to rule out women with serious psychological problems. Twenty controls and twenty subjects will be selected from the survey of 100 women. 2) Morning blood samples obtained on a daily basis during the luteal phase will subsequently be assayed for estradiol, progesterone, testosterone, and their protein carriers, estrogen binding protein, sex hormone binding globulin and cortisol binding protein. Peripheral levels of these hormones will be compared between the two groups of women to determine their possible effect on symptomatology. 3) The central nervous system is thought to have a very significant role in the etiology of this disease process. The neurotransmitters epinephrine, norepinephrine, dopamine and serotonin will be evaluated by the collection of first voided morning urine samples. The levels of their metabolites will be determined using high pressure liquid chromatography. 4) Endogenous opiods, such as immunoreactive Betaendorphins, are known to influence mood and behavior and vary during the menstrual cycle. They will be evaluated to determine their role in the premenstrual syndrome. Since peripheral levels of Betaendorphins are not reflective of CNS activity, portal blood levels will be investigated by the use of the opiod antagonist naloxone with subsequent measurement of luteinizing hormone and prolactin. Analysis of the data, derived from the above investigations, should result in an intergraded pattern which will clearly define the pathophysiology of the premenstrual syndrome.