Table 3. Meta-analysis results for ventricular, subcortical and intracranial volumes, comparing MDD-SB vs healthy CTL.

Brain volume	Cohen'sd (CTL vs MDD-SB)	Std. err.	95% CI	% Difference	P-value	Heterogeneity (i2)	# CTL	# MDD-SB
Lateral ventricles	0.022	0.093	[−0.159, 0.204]	0.24	0.80	0.00	1713	103
Thalamus	−0.252	0.093	[−0.434, −0.69]	−2.70	0.007	0.00	1695	102
Caudate	−0.223	0.132	[−0.481, 0.036]	−1.69	0.09	45.39	1682	107
Putamen	−0.155	0.094	[−0.338, 0.029]	−1.65	0.10	0.00	1628	100
Pallidum	−0.027	0.093	[−0.210, 0.156]	−0.29	0.78	0.00	1661	101
Hippocampus	−0.164	0.091	[−0.343, 0.015]	−1.79	0.07	0.00	1685	107
Amygdala	−0.095	0.091	[−0.273, 0.084]	−1.04	0.30	0.00	1697	107
Accumbens	−0.206	0.093	[−0.388, −0.023]	−2.21	0.03	0.00	1589	102
ICV	−0.071	0.199	[−0.461, 0.320]	−0.35	0.72	76.69	1799	111

Abbreviations: CI, confidence interval; CTL, controls; ICV, intracranial volume; MDD, major depressive disorder; MDD-SB, MDD patients with suicidal planning/attempt; std. err., standard error.

Age, sex, scan centre and ICV were used as covariates. Adjusted Cohen's d are reported.

Samples included: NESDA, SHIP, SHIP-Trend, Sydney, QTIM. Samples excluded: DepOx and CODE. Significance threshold: P<0.00146; i² indicates heterogeneity across studies.