This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. To determine if circadian rhythm disturbances, as measured by melatonin, contribute to the pathogenesis of postpartum depression and if these chronobiological disturbances can be treated by shifting the sleep-wake cycle and with phototherapy.