Stability of plasma catecholamine metabolites in outpatient schizophrenics

Abstract

for tardive dyskinesia vulnerability, we conducted a post hoc analysis of plasma AA levels and BPRS symptoms. Subjects were 53 randomly selected young male chronic schizophrenic inpatients having three to 20 years of neuroleptic treatment. Pearson correlation coefficients were calculated between LNAA levels and ratios as compared to BPRS individual item scores and BPRS factor scores. Most of the LNAAs were found to have significant positive correlations with psychotic symptoms. TYR had only positive correlations with depression and anxiety. The branched chain amino acids (valine, isoleucine, and leucine) also showed positive correlations with depressive symptoms. Though PHE, TYR, and TRP have been the primary focus of this line of research, fasting HIS (a precursor of histamine which is a probable neurotransmitter) was found to have significant negative correlations with the following BPRS items: mannerisms, conceptual disorganization, grandiosity, unusual thought content, disorientation, total BPRS score; and the factors of thought disorder, activation, and hostility/suspiciousness. A positive correlation was found for blunted affect. Postloading levels, however, did not show any significant associations. These preliminary findings suggest that future research in the AAs and mental illness should include a broader range of AAs such as HIS and their relationships to symptomatology .