Table 4. Meta-analysis results for ventricular, subcortical and intracranial volumes, comparing MDD-SS vs healthy CTL.

Brain volume	Cohen'sd (CTL vs MDD-SS)	Std. err.	95% CI	% Difference	P-value	Heterogeneity (i2)	# CTL	# MDD-SS
Lateral ventricles	0.084	0.059	[−0.032, 0.201]	1.41	0.16	0.00	1910	441
Thalamus	−0.121	0.060	[−0.238, −0.005]	−2.04	0.04	0.00	1892	443
Caudate	−0.077	0.082	[−0.237, 0.084]	−0.94	0.35	42.59	1879	445
Putamen	−0.065	0.067	[−0.197, 0.067]	−0.97	0.33	16.36	1825	435
Pallidum	−0.061	0.060	[−0.179, 0.056]	−1.02	0.31	0.00	1861	433
Hippocampus	−0.085	0.075	[−0.232, 0.062]	−1.14	0.26	32.89	1882	443
Amygdala	−0.101	0.059	[−0.217, 0.015]	−1.71	0.89	0.00	1894	441
Accumbens	−0.056	0.060	[−0.173, 0.062]	−0.93	0.35	0.00	1786	425
ICV	−0.058	0.106	[−0.266, 0.150]	−0.55	0.59	66.57	1996	453

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

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

Samples included: all seven samples were included. Samples excluded: none. Significance threshold: P<0.00146; i² indicates heterogeneity across studies.