Glutamate and glutamine in the anterior cingulate and thalamus of medicated patients with chronic schizophrenia and healthy comparison subjects measured with 4.0-T proton MRS - Theberge, J; Al-Semaan, Y; Williamson, PC; Menon, RS; Neufeld, RW; Rajakumar, N; Schaefer, B; Densmore, M; Drost, DJ (Am J Psychiatry, 2003)