New neurons are generated through the process of neurogenesis. Although most active during pre-natal development, neurogenesis persists throughout the human lifespan. In adulthood, neurogenesis occurs predominantly in the subgranular zone of the hippocampal dentate gyrus. A highly novel methodology using Magnetic Resonance Spectroscopy (MRS) has recently been developed to measure the formation of hippocampal newborn stem cells in the human brain. We propose to assess Neural Progenitor Cells (NPCs) in the neuropsychiatric disorder cocaine dependence, a chronic disease process associated with pathology of the hippocampus and impaired neurogenesis. In addition, we will assess other measures associated with neurogenesis, including hippocampal (dentate gyrus) cerebral blood volume (CBV) using Vascular-Space-Occupancy (VASO) Magnetic Resonance Imaging. We predict that newborn hippocampal cells [or neuronal progenitor cells (NPCs] will be attenuated in recently using cocaine-addicted participants relative to abstinent and control participants, and that these changes will be paralleled by changes in CBV. In this pilot study, we will assess for these changes in cocaine-addicted subjects who are actively using cocaine and those who are recently abstinent (three to six months) as well as age-, race-, and gender-similar control participants.