Dynamics of melanin-concentrating hormone (MCH) serum levels in major depressive disorder during antidepressant treatment

BackgroundIn preclinical studies, the hypothalamic polypeptide melanin-concentrating hormone (MCH) has been shown to be involved in depression-like behavior and modulations of MCH and MCH-receptors were proposed as potential new antidepressant drug targets.MethodsFor the first time, MCH serum levels were explored in 30 patients with major depressive disorder (MDD) prior to (T1) and after 2 (T2) and 4 weeks (T3) of antidepressant treatment and in 30 age- and sex-matched healthy controls by applying a fluorescence immunoassay.ResultsLevels of MCH did not differ significantly between un-medicated patients (444.11±174.63 pg/mL SD) and controls (450.68±210.03 pg/mL SD). In MDD patients, MCH levels significantly decreased from T1 to T3 (F=4.663; p=0.013). Post-hoc analyses showed that these changes were limited to patients treated with mirtazapine but not escitalopram and female but not male patients. MCH-levels showed high correlations from T1 to T3 (r≥0.964, p<0.001) and were found to correlate significantly with parameters of sleep within the controls.LimitationsSmall sample size. No follow-up measures were performed within the control group.ConclusionsOur findings suggest peripheral MCH-levels not to be altered in depression but possibly reflecting depression-related state properties that can be modulated by sleep, medication and sex.