Depressive symptoms may explain elevated plasma levels of homocysteine in females with eating disorders.

Elevated plasma homocysteine levels have been found in different psychiatric disorders, including major depression and eating disorders. The aim of the present study was to evaluate whether presence of depression or depressive symptoms is associated with elevated homocysteine levels in patients with eating disorders. Total plasma homocysteine levels were assessed in 44 females with anorexia nervosa (n = 21) or bulimia nervosa (n = 23). Comorbid major depressive disorder (MDD) was diagnosed according to DSM-IV criteria using a semi-structured interview (SCID-I). Furthermore, depressive symptoms were assessed using Beck's depression inventory (BDI). Presence of MDD was not associated with elevated homocysteine levels (t-test: T = 0.42; df = 42; P = 0.68). However, self-rated presence of clinically relevant depressive symptoms (BDI score18) was associated with elevated homocysteine (T = -2.8; df = 42; P = 0.008). Presence of depressive symptoms may explain elevated homocysteine levels previously reported in patients with eating disorders or vice versa. Longitudinal studies are needed to unravel this hen or egg problem.