• disorders
• inflammatory
• mood
• system
• vitamin

The immune and inflammatory systems, along with changes in their biochemical markers, have been extensively studied in mood disorders like major depression and bipolar disorder. Indeed, an ever-growing body of evidence is showing that patients have activated inflammatory patterns that result from altered neurotransmission and an abnormally regulated neuroendocrine response to stress. Bidirectionally, inflammatory patterns have been found to provoke impaired neurotransmission, stress coping, and metabolism in mood disorders. Moreover, several clinical surveys have reported that plasma levels of some pro-inflammatory cytokines and acute phase proteins can vary depending on the phases of these disorders.
In such a context, the present study aimed to evaluate peripheral metabolic parameters and plasma/serum levels of essential nutrients in a group of inpatients affected by mood disorders, and to compare them to the same biological indexes measured in a control sample. Specifically, the study compared blood glucose, lipoproteins, triglycerides, uric acid, blood urea nitrogen (BUN), transaminases and other haemato-chemical parameters, together the plasma/serum levels of some vitamins (vitamin D, B12, folate) and homocysteine, a key substrate of methionine metabolism which is involved in crucial pleiotropic enzyme reactions in the body. Results showed that most patients, despite their heterogeneity in diagnosis and clinical presentation, were highly defective in circulating vitamin D levels, not only in respect to control subjects, but even in respect to the general population normative cut-off values P< .0001). This vitamin D result was paralleled by increased serum homocysteine concentrations in patients vs. controls (P<.0001), indicating an imbalance in their methionine metabolism, a finding suggesting the impairment at the level of methylation patterns and redox regulatory fluxes in affected subjects. Surprisingly, homocysteine levels were negatively correlated with vitamin D, vitamin B12 and folate values in control subjects, but not in patients, suggesting that changes of methionine metabolism and vitamin deficits were occurring independently in patients. In addition, patients displayed higher blood glucose and lower BUN than controls, indicating an impaired protein-to-carbohydrate metabolism and/or altered nutritional/dietary status, such as the preferential assumption of carbohydrates rather than proteins. Briefly, we provide herein further support to the notion that mood disorder patients are a population where vitamin deficits, dysmetabolism and/or dietary defects are very common features. As a corollary, we want to emphasize herein that people affected by major depressive disorder (MDD) or bipolar disorders (BDs) are exposed to a greater risk of a variety of somatic illnesses than the general population.
In conclusion, our findings might represent a starting point for discovering new molecular targets for more customized treatments, as well as for implementing focused healthcare interventions, such as nutritional measures and the co-administration of essential substances together with psychotropic drugs and/or psychological therapies.