CLINICAL IMPLICATIONS OF BIOMARKERS INSEVERE MOOD DISORDERS

Objectives: The aim of this symposium is to discuss the clinical implications of biomarkers (neuro-imaging and peripheral) in pre- and early phases of severe mood disorders (MD). Methods: The symposia will include a presentation from each of the 4 leading international research groups conducting research on the identification of potential neuro-imaging/peripheral markers for vulnerability, disease expression, and treatment response in pre- and early phases of severe MD. The presenters will focus on the clinical implications of 1) measurement of the cerebral blood flow; 2) neural markers in the brain; 3) peripheral lipid peroxidation; and 4) peripheral neuro-immune markers. Results: Neuroimaging and peripheral studies showed that the cerebral blood flow, neural activity, lipid peroxidation, and neuro-immune state are different between adolescents in pre-/early phases of MD and controls but varied from each other in clinical implications. For example, the cerebral blood flow is elevated in four frontal regions of the brain in adolescents with bipolar disorder (BD). A single bout of moderate-intensity aerobic exercise reduced regional cerebral blood flow to a greater extent in BD compared to controls; these time-dependent cerebral blood flow responses were associated with exercise-induced feelings (t=-2.7, df=46, p=0.01). The neuroimaging study in BD youth, unipolar depression (UD), and healthy control (HC) youth found that BD youth, relative to UD, showed significantly lower activity to intense emotional faces especially with happy faces, suggesting that neural activity during processing of emotion processing and working memory with positive emotional stimuli and response inhibition can help differentiate BD from UD in youth. The "peripheral" studies investigated the predictive value of lipid peroxidation and neuroimmune markers in populations at high risk for BD. The reported findings were contrary: lipid peroxidation levels were found to be decreased in BD adolescents compared to controls, while the at risk groups fell in between HC and BD. In contrast, an abberant neuro-immune state in bipolar offspring was found, but this state was not directly related to the presence or development of a BD over time. Conclusions: Further research involving larger collaborative studies is needed to validate these potential biomarkers prior to engaging them for clinical use.