ACC	Anterior Cingulate Cortex
ADC	Apparent Diffusion Coefficient
AFDtot	Apparent Fiber Density Total
AUDIT	Alcohol Use Disorders Identification Test
BDI	Beck Depression Inventory
BDI-II	Beck Depression Inventory-II
BOLD	Blood Oxygen Level-Dependent
CES-D	Center for Epidemiologic Studies Depression Scale
CMDI	Chicago Multiscale Depression Inventory
CSF	Cerebrospinal Fluid
DIR	Double Inversion Recovery
DMN	Default Mode Network
DSM-V	Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition
DTI	Diffusion Tensor Imaging
DWI	Diffusion-Weighted Imaging
ECN	Executive Control Network
EDSS	Expanded Disability Status Scale
EPI	Echo Planar Imaging
FA	Fractional Anisotropy
FC	Functional Connectivity
FLAIR	Fluid-Attenuated Inversion Recovery
fMRI	Functional Magnetic Resonance Imaging
FSS	Fatigue Severity Scale
FWF	Free Water Fraction
Gad+	Gadolinium-Enhancing
GGT	Gamma-Glutamyl Transferase
GM	Gray Matter
GRE	Gradient Recalled Echo
HADS	Hospital Anxiety and Depression Scale
HADS-A	Hospital Anxiety and Depression Scale—Anxiety
HADS-D	Hospital Anxiety and Depression Scale—Depression
HARDI	High Angular Resolution Diffusion Imaging
HDRS	Hamilton Depression Rating Scale
HPA	Hypothalamic–Pituitary–Adrenal
HRQoL	Health-Related Quality of Life
MADRS	Montgomery–Åsberg Depression Rating Scale
MD	Mean Diffusivity
MMSE	Mini-Mental State Examination
MP-RAGE	Magnetization Prepared Rapid Gradient Echo
MPR2RAGE	Magnetization Prepared 2 Rapid Gradient Echoes
MPRAGE	Magnetization Prepared Rapid Acquisition Gradient Echo
MRI	Magnetic Resonance Imaging
MS	Multiple Sclerosis
N/A	Not Applicable
NAWM	Normal-Appearing White Matter
NHPT	Nine-Hole Peg Test
NuFO	Number of Fiber Orientations
OFC	Orbitofrontal Cortex
PCC	Posterior Cingulate Cortex
PD	Proton Density
PFC	Prefrontal Cortex
PHQ-2	Patient Health Questionnaire-2
PHQ-9	Patient Health Questionnaire-9
PROMIS	Patient-Reported Outcomes Measurement Information System
PwMS	People with Multiple Sclerosis
RD	Radial Diffusivity
ROI	Region of Interest
RRMS	Relapsing–Remitting Multiple Sclerosis
rs-fMRI	Resting-State Functional Magnetic Resonance Imaging
S-ANX	State Anxiety
SN	Salience Network
SPMS	Secondary Progressive Multiple Sclerosis
STAI	State-Trait Anxiety Inventory
STAI-T	State-Trait Anxiety Inventory—Trait
STAIS-5	State Anxiety Inventory Short Form
STAIT-5	Trait Anxiety Inventory Short Form
SVR	Support Vector Regression
T-ANX	Trait Anxiety
T1W	T1-Weighted
T2LL	T2 Lesion Load
T2W	T2-Weighted
UF	Uncinate Fasciculus
VBM	Voxel-Based Morphometry
WM	White Matter
WML	White Matter Lesion
WMLL	White Matter Lesion Load