SERUM MG2+ AND CA2+ MG2+ RATIO IN MAJOR DEPRESSIVE DISORDER/

Serum Mg2+ has been implicated in the symptom severity and pathophysio logy of mood disorders. Furthermore, the recent findings of blunted si gnalling through the G-protein-coupled adenylyl cyclase (AC) pathway i n major depressive disorder (MDD) and the importance of Mg2+ in G-prot ein/AC function led us to reexamine in a large sample whether serum Mg 2+ concentrations were decreased in MDD patients. In 145 drug-free MDD patients compared with 2 control groups: (a) patients with bipolar di sorder (n = 33) and (b) non-mood-disordered patients (n = 47), there w ere no differences in Mg2+ levels or Ca2+/Mg2+ ratios. Neither of thes e measures differed when comparing responders and nonresponders to ant idepressant treatment.