Plasma levels of tetrahydrobiopterin and folate in major depression

Abstract

Plasma levels of tetrahydrobiopterin (BH 4) and the related pterin folate were concurrently measured in 20 pairs of depressed patients and age-matched controls. The mean values of plasma BH 4 in depressed patients was significantly elevated to a level about 150% of that found in the controls. Folate levels were not different between groups. These findings emphasize that BH 4, a required cofactor in the biosynthesis of catecholamines and indolamines, is altered in depression.