The plasma and platelet PEA levels of 20 normal subjects and 17 schizophrenic patients were investigated using a high-performance liquid chromatography. In the normals the mean plasma and platelet levels of PEA were 4.9 +/- 1.9 ng/ml and 1.78 +/- 1.01 ng/mg protein, respectively, while in the schizophrenics, those were 12.1 +/- 7.9 ng/ml and 0.77 +/- 0.5 ng/mg protein, respectively. The plasma PEA levels of the schizophrenics were significantly higher than those of the normals, and the platelet PEA levels of the schizophrenics were lower than those of the normals.