We propose to measure the response of symptoms and cognition in people schizophrenia given acamprosate or placebo. We hypothesize that symptoms and cognition will improve following two weeks of acamprosate. We will also use proton magnetic resonance spectroscopy (MRS) to examine the effect of acamprosate on glutamate & glutamine (Glu&Gln) brain levels in people with schizophrenia. We hypothesize that Glu&Gln concentrations in people with chronic schizophrenia will increase following two weeks of treatment with acamprosate.