Is plasma serine a marker for psychosis?

There is some disagreement in the literature concerning the use of plasma serine concentrations as a biological marker for psychoses including schizophrenia. The groups studying this phenomenon have used different methodologies, including gas chromatography and classical amino acid analysis. In the present study, using high pressure liquid chromatography to analyze plasma amino acids from schizophrenics and controls, we found no difference in plasma serine concentrations. None of the plasma amino acid concentrations that were measured differed significantly between schizophrenics and controls but the basic amino acids tended toward higher concentrations in schizophrenics.