Brain volume abnormalities in major depressive disorder: a meta-analysis of magnetic resonance imaging studies.
OBJECTIVE
So far, there have been no attempts to integrate the growing number of all brain volumetric magnetic resonance imaging studies in depression. In this comprehensive meta-analysis the magnitude and extent of brain volume differences between 2,418 patients with major depressive disorder and 1,974 healthy individuals from 64 studies was determined.


METHODS
A systematic research was conducted for volumetric magnetic resonance imaging studies of patients with major depressive disorder in relation to healthy control subjects. Studies had to report sufficient data for computation of effect sizes. For each study, the Cohen's d was calculated. All analyses were performed using the random effects model. Additionally, meta-regression analyses were done to explore the effects of potential sources of heterogeneity.


RESULTS
Patients showed large volume reductions in frontal regions, especially in the anterior cingulate and orbitofrontal cortex with smaller reductions in the prefrontal cortex. The hippocampus, the putamen and caudate nucleus showed moderate volume reductions.


CONCLUSIONS
This is the first comprehensive meta-analysis in major depressive disorder demonstrating structural brain abnormalities, particularly in those brain areas that are involved in emotion processing and stress-regulation.
Department of Psychiatry, Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands. p.c.m.p.koolschijn@umcutrecht.nl
P Cédric M P
PC
Koolschijn
Neeltje E M
NE
van Haren
Gerty J L M
GJ
Lensvelt-Mulders
Hilleke E
HE
Hulshoff Pol
René S
RS
Kahn
D001921:Brain / Q000473:pathology*; D001931:Brain Mapping; D016206:Databases, Bibliographic / Q000706:statistics & numerical data; D003865:Major Depressive Disorder / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging