Amino acid studies in transient acute polymorphic psychosis

Data are reviewed on the amino acid metabolism in patients suffering from transient acute polymorphic psychoses according to ICD-10. The psychotic episodes of many of these patients are characterized by distorted sensory perceptions and intense emotional states; plasma amino acid analysis revealed a disturbed serine-glycine metabolism. In remitted patients oral loading with serine induced the characteristic dysperceptions and psychedelic symptoms. Plasma concentrations of serine and methionine were decreased, and the concentration of taurine was increased. Fibroblast experiments suggest that the activities of the serine metabolizing enzymes serine hydroxymethyltransferase and cystathionine beta-synthase are increased in these patients. The determination of plasma amino acid concentrations proved to be useful in discriminating these patients, The prevalence of this transient psychosis in a psychiatric in-patient population ranged between 1.4 and 3.6%.