Table 2. Meta-analysis results for ventricular, subcortical and intracranial volumes, comparing MDD-SI vs healthy CTL.

Brain volume	Cohen'sd (CTL vs MDD-SI)	Std. err.	95% CI	% Difference	P-value	Heterogeneity (i2)	# CTL	# MDD-SI
Lateral ventricles	0.119	0.071	[−0.020, 0.257]	1.68	0.09	0.00	1910	292
Thalamus	−0.063	0.071	[−0.202, 0.075]	−0.90	0.37	0.00	1892	293
Caudate	−0.011	0.074	[−0.156, 0.133]	−0.15	0.88	7.40	1879	294
Putamen	−0.026	0.100	[−0.222, 0.170]	−0.26	0.79	46.36	1825	289
Pallidum	−0.069	0.072	[−0.209, 0.071]	−0.97	0.33	0.00	1861	288
Hippocampus	−0.052	0.087	[−0.222, 0.118]	−0.60	0.55	30.81	1882	293
Amygdala	−0.106	0.071	[−0.244, 0.033]	−1.49	0.14	0.00	1894	292
Accumbens	0.022	0.073	[−0.121, 0.166]	0.30	0.76	3.91	1786	287
ICV	−0.028	0.096	[−0.217, 0.160]	−0.29	0.77	44.16	1996	298

Abbreviations: CI, confidence interval; CTL, controls; ICV, intracranial volume; MDD, major depressive disorder; MDD-SI, MDD patients with suicidal ideation; 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.