Table 1. Clinical descriptors for the TRD and healthy control groups in the structural MRI analysis.

Variables are shown as mean (standard deviation).

	MDD	Controls
Age	51.80 (11.23)	46.14 (13.97)	n.s.
IQ	122.75 (4.71)	116.95 (27.38)	n.s.
Female/Total*	15/20	15/21	n.s.
HDRS17	16.10 (5.58)	0.48 (0.93)	<0.001
MADRS	22.50 (7.97)	0.48 (1.03)	<0.001
BDI	32.20 (11.38)	0.43 (0.87)	<0.001
MGH-S	13.25 (10.49)	N/A	N/A

*chi-square test with other tests being t-tests.