MDD	Major depressive disorder
MRI	Magnetic resonance imaging
REM	Rapid eye movement
CBT	Cognitive behavior therapy
BDNF	Brain-derived neurotrophic factor
EEG	Electroencephalography
fMRI	Functional magnetic resonance imaging
DTI	Diffusion tensor imaging
MRS	Magnetic resonance spectroscopy
NIRS	Near-infrared spectroscopy
PET	Positron emission tomography
SPECT	Single-photon emission computed tomography
SSRI	Selective serotonin reuptake inhibitor
ECT	Electroconvulsive therapy
SNRI	Serotonin–norepinephrine reuptake inhibitor
FA	Fractional anisotropy
MD	Mean diffusivity
TBSS	Track-Based Spatial Statistics
RD	Radial diffusivity
RSFC	Resting state functional connectivity
rTMS	Repetitive transcranial magnetic stimulation
18FDG-PET	(18)F-fluoro-2-deoxy-d-glucose PET
SERT	Serotonin transporter
rCBF	Regional cerebral blood flow
GABA	Gamma-aminobutyric acid
5-HTTLPR	Serotonin transporter-linked promoter region
CAN-BIND	Canadian Biomarker Integration Network in Depression