Increased cerebrospinal fluid glutamine levels in depressed patients

Background: There is increasing evidence far an association between alterat ions of brain glutamatergic neuro-transmission? and the pathophysiology of affective disorders. Methods: We studied the association between cerebrospinal fluid (CSF) metab olites, including glutamine, in unipolar and bipolar depressed patients ver sus control subjects using a proton magnetic resonance spectroscopy techniq ue. Cerebrospinal fluid samples were obtained from 18 hospitalized patients with acute unmedicated severe depression without medical problems and comp ared with those of 22 control subjects. Results: Compared with the control group, the depressed patient group had s ignificantly higher CSF glutamine concentrations, which correlated positive ly with CSF magnesium levels. Conclusions: These findings suggest art abnormality of the brain glial-neur onal glutamine/glutamate cycle associated with N-methyl-D-aspartate recepto r systems in patients with depression. (C) 2000 Society of Biological Psych iatry.