Subcortical brain alterations in major depressive disorder: findings from the ENIGMA Major Depressive Disorder working group.
Schmaal L., Veltman DJ., van Erp TG., Sämann PG., Frodl T., Jahanshad N., Loehrer E., Tiemeier H., Hofman A., Niessen WJ., Vernooij MW., Ikram MA., Wittfeld K., Grabe HJ., Block A., Hegenscheid K., Völzke H., Hoehn D., Czisch M., Lagopoulos J., Hatton SN., Hickie IB., Goya-Maldonado R., Krämer B., Gruber O., Couvy-Duchesne B., Rentería ME., Strike LT., Mills NT., de Zubicaray GI., McMahon KL., Medland SE., Martin NG., Gillespie NA., Wright MJ., Hall GB., MacQueen GM., Frey EM., Carballedo A., van Velzen LS., van Tol MJ., van der Wee NJ., Veer IM., Walter H., Schnell K., Schramm E., Normann C., Schoepf D., Konrad C., Zurowski B., Nickson T., McIntosh AM., Papmeyer M., Whalley HC., Sussmann JE., Godlewska BR., Cowen PJ., Fischer FH., Rose M., Penninx BW., Thompson PM., Hibar DP.
The pattern of structural brain alterations associated with major depressive disorder (MDD) remains unresolved. This is in part due to small sample sizes of neuroimaging studies resulting in limited statistical power, disease heterogeneity and the complex interactions between clinical characteristics and brain morphology. To address this, we meta-analyzed three-dimensional brain magnetic resonance imaging data from 1728 MDD patients and 7199 controls from 15 research samples worldwide, to identify subcortical brain volumes that robustly discriminate MDD patients from healthy controls. Relative to controls, patients had significantly lower hippocampal volumes (Cohen's d=-0.14, % difference=-1.24). This effect was driven by patients with recurrent MDD (Cohen's d=-0.17, % difference=-1.44), and we detected no differences between first episode patients and controls. Age of onset ⩽21 was associated with a smaller hippocampus (Cohen's d=-0.20, % difference=-1.85) and a trend toward smaller amygdala (Cohen's d=-0.11, % difference=-1.23) and larger lateral ventricles (Cohen's d=0.12, % difference=5.11). Symptom severity at study inclusion was not associated with any regional brain volumes. Sample characteristics such as mean age, proportion of antidepressant users and proportion of remitted patients, and methodological characteristics did not significantly moderate alterations in brain volumes in MDD. Samples with a higher proportion of antipsychotic medication users showed larger caudate volumes in MDD patients compared with controls. This currently largest worldwide effort to identify subcortical brain alterations showed robust smaller hippocampal volumes in MDD patients, moderated by age of onset and first episode versus recurrent episode status.