Menstrual History Diary: Drug craving mood and affect have been associated with menstrual cycle phase and ovarian hormone status. Subjects will be asked to estimate the timing of their cycle for the 90-days prior to study entry and to track their cycle during study participation. Daily Hassles Scale: The Daily Hassles Scale consists of a list of 117 irritating, frustrating or distressing events that characterize everyday interactions with the environment. Subjects rate intensity for the past month. The Daily Hassles Scale is positively correlated with adaptational outcomes and is a good predictor of psychological symptoms. Data from the daily hassles will be used to explore the relationship between stress related corticolimbic brain activity and sensitivity to daily hassles.