Subjects will undergo proton magnetic resonance spectroscopy (MRS) at 4T. In addition, in accordance with the McLean Hospital Neuroimaging center guidelines, subjects will additionally have a MR screening scan at either 1.5T or 3T. All MR recordings will be obtained using parameters that are within FDA safety guidelines for exposure to static magnetic fields, radio-frequency energy deposition, magnetic field switching rates and acoustic noise levels. GABA and glutamate levels will be derived from MRS Scan at 4T. Subjects will be in each scanner for approximately one hour. At the conclusion of each scan, subjects will be queried regarding any adverse effects related to MR scans. The subject will have completed the study at the conclusion of the MR scans.