Original Research ARTICLE

Front. Psychiatry, 08 March 2011 | http://dx.doi.org/10.3389/fpsyt.2011.00007

Functional connectivity of brain structures correlates with treatment outcome in major depressive disorder

F. Andrew Kozel1*, Uma Rao2, Hanzhang Lu3, Paul A. Nakonezny1,4, Bruce Grannemann1, Tamara McGregor5, Paul E. Croarkin1, Kimberly S. Mapes1, Carol A. Tamminga1 and Madhukar H. Trivedi1
  • 1 Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA
  • 2 Department of Psychiatry and Behavioral Science and the Center for Molecular and Behavioral Neuroscience, Meharry Medical College, Nashville, TN, USA
  • 3 Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, USA
  • 4 Division of Biostatistics, Department of Clinical Sciences, University of Texas Southwestern Medical Center, Dallas, TX, USA
  • 5 Department of Family and Community Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA

Identifying biosignatures to assess the probability of response to an antidepressant for patients with major depressive disorder (MDD) is critically needed. Functional connectivity MRI (fcMRI) offers the promise to provide such a measure. Previous work with fcMRI demonstrated that the correlation in signal from one region to another is a measure of functional connectivity. In this pilot work, a baseline non-task fcMRI was acquired in 14 adults with MDD who were free of all medications. Participants were then treated for 8 weeks with an antidepressant and then clinically re-evaluated. Probabilistic anatomic regions of interest (ROI) were defined for 16 brain regions (eight for each hemisphere) previously identified as being important in mood disorders. These ROIs were used to determine mean time courses for each individual’s baseline non-task fcMRI. The correlations in time courses between 16 brain regions were calculated. These calculated correlations were considered to signify measures of functional connectivity. The degree of connectivity for each participant was correlated with treatment outcome. Among 13 participants with 8 weeks follow-up data, connectivity measures in several regions, especially the subcallosal cortex, were highly correlated with treatment outcome. These connectivity measures could provide a means to evaluate how likely a patient is to respond to an antidepressant treatment. Further work using larger samples is required to confirm these findings and to assess if measures of functional connectivity can be used to predict differential outcomes between antidepressant treatments.

Keywords: major depressive disorder, antidepressant, functional MRI, treatment prediction, connectivity, non-task fcMRI

Citation: Kozel FA, Rao U, Lu H, Nakonezny PA, Grannemann B, McGregor T, Croarkin PE, Mapes KS, Tamminga CA and Trivedi MH (2011) Functional connectivity of brain structures correlates with treatment outcome in major depressive disorder. Front. Psychiatry 2:7. doi:10.3389/fpsyt.2011.00007

Received: 22 December 2010; Accepted: 17 February 2011;
Published online: 08 March 2011.

Edited by:

Paul Fitzgerald, Monash University, Australia

Reviewed by:

John Hart, University of Texas at Dallas, USA
Jerome Joseph Maller, Monash Alfred Psychiatry Research Centre, Australia

Copyright: © 2011 Kozel, Rao, Lu, Nakonezny, Grannemann, Mcgregor, Croarkin, Mapes, Tamminga and Trivedi. This is an open-access article subject to an exclusive license agreement between the authors and Frontiers Media SA, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are credited.

*Correspondence: F. Andrew Kozel, Department of Psychiatry, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard Dallas, TX 75390-9119, USA. e-mail: andrew.kozel@utsouthwestern.edu