review of electroencephalographic changes in diabetes mellitus in relation to major depressive disorder Review (1038) Total Article Views Authors: Baskaran A, Milev R, McIntyre RS Published Date January 2013 Volume 2013:9 Pages 143 - 150 DOI: http://dx.doi.org/10.2147/NDT.S38720 Received: 02 October 2012 Accepted: 13 November 2012 Published: 17 January 2013 Anusha Baskaran,1,2 Roumen Milev,3 Roger S McIntyre2 1Centre for Neuroscience Studies, Queen's University, Kingston; 2Mood Disorders Psychopharmacology Unit, University Health Network, Toronto; 3Department of Psychiatry, Queen's University, Kingston, Canada Abstract: A bidirectional relationship exists between diabetes mellitus (DM) and major depressive disorder (MDD), with depression commonly reported in both type 1 DM (T1DM) and type 2 DM (T2DM), and depressive symptoms associated with a higher incidence of diabetes. However, how the two conditions are pathologically connected is not completely understood. Similar neurophysiological abnormalities have been reported in both DM and MDD, including elevated electroencephalographic (EEG) activity in low-frequency slow waves and increased latency and/or reduced amplitude of event-related potentials. It is possible that this association reflects some common underlying pathology, and it has been proposed that diabetes may place patients at risk for depression through a biological mechanism linking the metabolic changes of DM to changes in the central nervous system. In this review we will discuss EEG abnormalities in DM, as well as the biological mechanisms underlying various EEG parameters, in order to evaluate whether or not a common EEG biosignature exists between DM and MDD. Identifying such commonalities could significantly inform the current understanding of the mechanisms that subserve the development of the two conditions. Moreover, this new insight may provide the basis for informing new drug discovery capable of mitigating and possibly even preventing both conditions.