The proposed project is an outgrowth of the rapidly growing demand for medical treatment of premenstrual symptoms from women who feel that these symptoms are incapacitating. A conservative estimate that premenstrual symptoms are severe in 10 percent of females of reproductive age in the U.S. means that the problem touches large numbers of women. Treatment is often at considerable expense and inconvenience; physicians lack diagnostic criteria and controlled evaluation of treatment responses. At this time, there are no scientific data that clearly support contentions of treatment effectiveness. The specific aims of the proposed project are to (1) evaluate the efficacy of pyridoxine (Vitamin B6) for relief of premenstrual symptoms; (2) evaluate the efficacy of progesterone for relief of premenstrual symptoms; (3) determine which symptoms or symptom clusters are most likely to respond to these treatments and the relationships of intensity and timing of symptoms with treatment responses; (4) identify patient groups that are appropriately and inappropriately treated with these medications; and (5) report the safety of these medications for the dosages and time period of the study. At least 264 women will enter the treatment sequence in a double-blind crossover design. Phase I compares pyridoxine and placebo and also serves as a "washout" of placebo response; Phase II compares progesterone and placebo; Phase III evaluates stability of improvement for six additional menstrual cycles. Specific menstrual symptoms, intensity and timing will be assessed prior to treatment, on Day 25 (+ or - 4) each menstrual cycle during the study with an evaluation of symptom factors also on Day 9 (+ or - 4). Measures are at 10 time points using objective self-assessment instruments, daily symptom recordings, physician and counselor ratings. Descriptive and multivariate statistical methods are employed. Information from the study will provide guidelines for medical management of premenstrual symptoms: e.g. whether pyridoxine and progesterone are more effective than placebo; which symptoms respond to these treatments. It will increase diagnostic information on the subgroups of syndromes within the broad range of premenstrual symptoms.