Low levels of serum LDH are associated with depression and suicide attempts

A huge body of evidence has signaled a correlation between adult depression and energy metabolism. The key links are the energy supply and substrates for brain energy metabolism and the crucial signaling molecule lactate. Nevertheless, the association between lactate metabolism and depression remains elusive.The primary objective of this study was to explore the difference in serum LDH levels between patients with major depressive disorder (MDD) and the normal population and to determine whether LDH can be employed as a predictor of suicide attempt (SA) in MDD patients.Serum LDH levels were measured in 232 patients with MDD and 110 healthy controls. Depressive symptoms were assessed using the 24-item Hamilton Depression Scale (HAMD-24). The data were collected and analyzed with SPSS 22.0.The serum LDH level of the control group was (196.50 ± 34.40) U/L, while that of the MDD group was (177.94 ± 25.89) U/L (P < 0.001). Notably, the LDH level [(169.96 ± 25.31) U/L] in the SA group was significantly lower than that in the control and non-SA groups [(181.25 ± 25.47) U/L] (P < 0.01); There was no significant correlation with HAMD-24 score (P > 0.05). Collectively, this study demonstrated that a decrease in serum LDH levels is an independent risk factor for SA in MDD patients.Our results imply that a decrease in LDH levels may be associated with MDD and suicidal behaviors. Early identification of suicide risk and evaluation of the prognosis of depression is critical.