Pharmacopsychiatry 2013; 46 - A11
DOI: 10.1055/s-0033-1353272

Prediction of unipolar and bipolar depression on the basis of pattern classification techniques using amygdala excitability to subliminally presented emotional faces

D Grotegerd 1, A Stuhrmann 1, H Kugel 2, S Schmidt 1, R Redlich 1, P Zwanzger 1, AV Rauch 1, W Heindel 2, P Zwitserlood 3, V Arolt 1, T Suslow 4, U Dannlowski 5
  • 1Department of Psychiatry, University of Münster, Germany
  • 2Department of Clinical Radiology, University of Münster, Germany
  • 3Institute of Psychology, University of Münster, Germany
  • 4Department of Psychosomatic Medicine and Psychotherapy, University of Leipzig, Germany
  • 5Department of Psychiatry, University of Marburg, Germany

Bipolar disorder and Major depressive disorder are difficult to differentiate during depressive episodes, leading to frequent misdiagnoses and suboptimal treatment. Hence, the identification of pathophysiological differences is a major research goal. Dysfunctional amygdala responsiveness during emotion processing has been implicated in both disorders, but the rapid and automatic stages of emotion processing in the amygdala have so far never been investigated in bipolar patients. fMRI data of 22 bipolar depressed patients (BD), 22 unipolar depressed patients (MDD), and 22 healthy controls (HC) were obtained during automatic processing of subliminally presented emotional faces. Group differences regarding amygdala responsiveness were investigated by using standard univariate analyses as well as pattern classification in order to differentiate the clinical groups. Univariate analysis revealed a significant group x emotion interaction within the left amygdala. Amygdala responsiveness to sad faces was increased in MDD relative to BD. In contrast, amygdala responsiveness to happy faces was higher in BD than in MDD. Pattern classification on amygdala activation to sad>happy faces yielded almost 80% accuracy differentiating MDD and BD patients. Distinct amygdala excitability during automatic stages of the processing of emotional faces may reflect differential pathophysiological processes in BD versus MDD depression, potentially representing diagnosis-specific neural markers. This study was supported by grants of Innovative Medizinische Forschung (IMF) of the Medical Faculty of Münster (DA120903 to UD and DA211012 to UD), and Rolf-Dierichs-Stiftung (ZUW80037 to UD)