Plasma and platelet amino acid concentrations in patients affected by major depression and under fluvoxamine treatment.

Plasma and platelet levels of 18 amino acids were measured in 29 outpatients (mean age +/- SD 47.41 +/- 10.85 years; 14 F, 15 M) affected by major depression (DSM IV) and in 28 healthy volunteers (mean age 42.46 +/- 14.19 years; 12 F, 16 M). Plasma and platelet levels of amino acids tended to be higher in depressed patients than in healthy controls. In particular, glutamate, taurine and lysine plasma levels and aspartate, serine and lysine platelet levels were significantly higher. Tryptophan/large neutral amino acids ratio (trp/LNAAs) was significantly lower in depressed patients. Fluvoxamine treatment did not influence plasma and platelet levels of amino acids or trp/LNAAs ratio.