title: Meta-analysis of volumetric abnormalities in cortico-striatal-pallidal-thalamic circuits in major depressive disorder.
abstract: BACKGROUND
  Abnormalities in cortico-striatal-pallidal-thalamic (CSPT) circuits have been implicated in major depressive disorder (MDD). However, the robustness of these findings across studies is unclear, as is the extent to which they are influenced by demographic, clinical and pharmacological factors.
  
  
  METHODS
  With the aim of clarifying these questions, we conducted a meta-analysis to map the volumetric abnormalities that were most robustly identified in CSPT circuits of individuals with MDD. A systematic search identified 41 studies meeting our inclusion criteria.
  
  
  RESULTS
  There were significant volume reductions in prefrontal (especially orbitofrontal) and anterior cingulate cortices, and also in subcortical structures such as the caudate nucleus and putamen, with effect sizes ranging from small to moderate. The subgenual anterior cingulate and orbitofrontal cortices were significantly smaller in antidepressant-free samples compared to medicated patients. Late-life depression (LLD) tended to be associated with smaller volumes in circumscribed frontal and subcortical structures, with the most robust differences being found in thalamic volume.
  
  
  CONCLUSIONS
  Individuals with major depression demonstrate volumetric abnormalities of CSPT circuits. However, these observations may be restricted to certain subgroups, highlighting the clinical heterogeneity of the disorder. On the basis of this meta-analysis, CSPT abnormalities were more prominent in those with LLD whereas antidepressant use seemed to normalize certain cortical volumetric abnormalities.
authors.affiliation: Department of Psychiatry, The University of Melbourne and Melbourne Health, VIC, Australia. ibora@unimelb.edu.au
authors.forename: E
authors.initials: E
authors.lastname: Bora
authors.forename: B J
authors.initials: BJ
authors.lastname: Harrison
authors.forename: C G
authors.initials: CG
authors.lastname: Davey
authors.forename: M
authors.initials: M
authors.lastname: Yücel
authors.forename: C
authors.initials: C
authors.lastname: Pantelis
mesh_terms: D000367:Age Factors; D001479:Basal Ganglia; D001921:Brain / Q000473:pathology* / Q000503:physiopathology; D001931:Brain Mapping; D035061:Control Groups; D003627:Data Interpretation, Statistical; D003865:Major Depressive Disorder / Q000473:pathology* / Q000503:physiopathology; D006179:Gyrus Cinguli; D006801:Humans; D008279:Magnetic Resonance Imaging; D017397:Prefrontal Cortex; D012044:Regression Analysis; D012720:Severity of Illness Index; D013788:Thalamus