Branched-Chain Amino Acids as New Biomarkers of Major Depression - A Novel Neurobiology of Mood Disorder.

The proteinogenic branched-chain amino acids (BCAAs) valine, leucine and isoleucine might play an unrecognised crucial role in the development of depression through their activation of the mammalian target of rapamycin (mTor) pathway. The aim of this research project is to evaluate whether BCAAs are altered in patients with major depression and might thus be appropriate biomarkers for major depression.The concentrations of valine, leucine and isoleucine were determined in 71 in-patients with major depression and 48 healthy controls by high-pressure liquid chromatography. Psychiatric and laboratory assessments were obtained at the time of in-patient admittance.The BCAAs are significantly decreased in patients with major depression in comparison with healthy subjects (valine: Mann-Whitney-U: 968.0; p