Hindawi Publishing Corporation ISRN Psychiatry Volume 2013, Article ID 568617, 10 pages http://dx.doi.org/10.1155/2013/568617 Research Article Different Neural Responses to a Moral Valence Decision Task in Unipolar and Bipolar Depression Daniele Radaelli, 1,2 Sara Dallaspezia, 1,2 Sara Poletti, 1,2 Enrico Smeraldi, 1,2 Andrea Falini, 2,3 Cristina Colombo, 1,2 and Francesco Benedetti 1,2 1 Department of Neuropsychiatric Sciences, Scientiic Institute, University Vita-Salute San Rafaele, San Rafaele Turro, Via Stamira d’Ancona 20, Milan, Italy 2 Centre of Excellence High Field Magnetic Resonance (C.E.R.M.A.C.), University Vita-Salute San Rafaele, Milan, Italy 3 Department of Neuroradiology, Scientiic Institute, University Vita-Salute San Rafaele, Milan, Italy Correspondence should be addressed to Daniele Radaelli; radaelli.daniele@hsr.it Received 2 October 2013; Accepted 12 November 2013 Academic Editors: A. Deveci and R. Milev Copyright © 2013 Daniele Radaelli et al. his is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Objectives. Patients afected by bipolar disorder (BP) and major depressive disorder (UP) share the susceptibility to experience depression and difer in their susceptibility to mania, but clinical studies suggest that the biological substrates of the two disorders could inluence the apparently similar depressive phases. he few brain imaging studies available described diferent brain metabolic and neural correlates of UP and BP. Methods. We studied the BOLD neural response to a moral valence decision task targeting the depressive biases in information processing in 36 subjects (14 BP, 11 UP, and 11 controls). Results. Main diferences between UP and controls and between UP and BP were detected in let ventrolateral prefrontal cortex (PFC, BA 47). Neural responses of BP patients difered from those of control subjects in multiple brain areas, including anterior cingulate cortex (ACC) and medial PFC, bilateral dorsolateral PFC, temporal cortex and insula, and parietal and occipital cortex. Conclusions. Our results are in agreement with hypotheses of dysfunctions in corticolimbic circuitries regulating afects and emotions in mood disorders and suggest that speciic abnormalities, particularly in ventrolateral PFC, are not the same in UP and BP depression. 1. Objective hough grouped in the “mood disorders” section of DSM, primary depressive disorder (unipolar depression, UP) and bipolar disorder (BP) show clearly distinctive features, most strikingly because patients share the possibility of experienc- ing major depression but difer in the susceptibility for mania. Several indings suggest a biological basis for this difer- ence. Genetic studies conirmed overlapping in the heritabil- ity of the two disorders but showed also that approximately 71% of the genetic inluence on liability to mania is distinct from the genetic liability to depression [1]. he occurrence of mania seems to be related to alterations in dopaminergic function [2, 3], with CSF homovanillic levels raising before the switch into manic phase [4] and urinary dopamine levels predicting manic mood [5], and it is then hypothesized that the biological mechanisms leading to these changes should be speciic of BP. Treatment options for UP and BP patients are diferent [6]. A lack of pharmaceutical trials comparing UP and BP prevents deinite conclusions, but current opinions suggest diferent strategies for the treatment of BP and UP depression [7–9], and the clinical evidence is that BP patients experi- ence depressive episodes that are more numerous and less responsive to antidepressant drug treatment [10] with most recent surveys showing that antidepressant drugs that are efective for UP are of little usefulness in BP [11]. Conversely, BP depression is more responsive to chronotherapeutic inter- ventions such as single [12] or repeated [13] sleep deprivation or light therapy [14]. Moreover, the same antidepressant drugs that can be administered to UP patients for years in order to prevent depressive recurrences will precipitate a manic episode in BP patients. hough early comparative studies of the biological distinction between BP and UP depression failed to provide sound evidence [15], these data suggest that the biological diferences between the two disorders could not