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BioMed Research International
Volume 2014, Article ID 706157, 9 pages
http://dx.doi.org/10.1155/2014/706157
Research Article

Neuroanatomical Classification in a Population-Based Sample of Psychotic Major Depression and Bipolar I Disorder with 1 Year of Diagnostic Stability

1Laboratory of Psychiatric Neuroimaging (LIM-21), Department and Institute of Psychiatry, Faculty of Medicine, University of São Paulo, Dr. Ovídio Pires de Campos Street, 3rd Floor, LIM-21, Nuclear Medicine Center, 05403-010 São Paulo, SP, Brazil
2Center for Interdisciplinary Research on Applied Neurosciences (NAPNA), Nuclear Medicine Center, University of São Paulo, Dr. Ovídio Pires de Campos Street, 3rd Floor, LIM-21, Nuclear Medicine Center, 05403-010 São Paulo, SP, Brazil
3Section of Biomedical Image Analysis (SBIA), Department of Radiology, University of Pennsylvania, 3600 Market Street, Suite 380, Philadelphia, PA 19104, USA
4Laboratory of Neuroscience (LIM-27), Department and Institute of Psychiatry, Faculty of Medicine, University of São Paulo, Dr. Ovídio Pires de Campos Street, 3rd Floor, LIM-27, Institute of Psychiatry, 05403-010 São Paulo, SP, Brazil
5Department of Preventive Medicine, Faculty of Medicine, University of São Paulo, 455 Dr. Arnaldo Avenue, 01246-903 São Paulo, SP, Brazil
6Laboratory of Psychopharmacology and Clinical Psychophysiology (LIM-23), Department and Institute of Psychiatry, Faculty of Medicine, University of São Paulo, Dr. Ovídio Pires de Campos Street, Ground Floor, LIM-23, Institute of Psychiatry, 05403-010 São Paulo, SP, Brazil

Received 3 October 2013; Revised 10 December 2013; Accepted 10 December 2013; Published 19 January 2014

Academic Editor: John A. Sweeney

Copyright © 2014 Mauricio H. Serpa et al. This 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.

Abstract

The presence of psychotic features in the course of a depressive disorder is known to increase the risk for bipolarity, but the early identification of such cases remains challenging in clinical practice. In the present study, we evaluated the diagnostic performance of a neuroanatomical pattern classification method in the discrimination between psychotic major depressive disorder (MDD), bipolar I disorder (BD-I), and healthy controls (HC) using a homogenous sample of patients at an early course of their illness. Twenty-three cases of first-episode psychotic mania (BD-I) and 19 individuals with a first episode of psychotic MDD whose diagnosis remained stable during 1 year of followup underwent 1.5 T MRI at baseline. A previously validated multivariate classifier based on support vector machine (SVM) was employed and measures of diagnostic performance were obtained for the discrimination between each diagnostic group and subsamples of age- and gender-matched controls recruited in the same neighborhood of the patients. Based on T1-weighted images only, the SVM-classifier afforded poor discrimination in all 3 pairwise comparisons: BD-I versus HC; MDD versus HC; and BD-I versus MDD. Thus, at the population level and using structural MRI only, we failed to achieve good discrimination between BD-I, psychotic MDD, and HC in this proof of concept study.