ACTH	Adrenocorticotropic Hormone
ADME	Absorption, Distribution, Metabolism, Excretion
AIS	Athens Insomnia Scale
API	Active Pharmaceutical Ingredient
BDI	Beck Depression Inventory
BIS/BAS	Behavioral Inhibition System/Behavioral Activation System
BL-VAS	Bond–Lader Visual Analog Scale
CAR	Cortisol Awakening Response
CANTAB	Cambridge Neuropsychological Test Automated Battery
CFS	Chalder Fatigue Scale
CYP	Cytochrome P450
EEG	Electroencephalogram
ENS	Enteric Nervous System
EAT	Eating Attitudes Test
ESS	Epworth Sleepiness Scale
FAST™	Fatigue Avoidance Scheduling Tool
FFQ	Food Frequency Questionnaire
FMT	Fecal Microbiota Transplantation
GABA	γ-Aminobutyric Acid
GAD	Generalized Anxiety Disorder
GASS	Glasgow Antipsychotic Side-effect Scale
GH	Growth Hormone
GHQ	General Health Questionnaire
GI-VAS	Gastrointestinal Visual Analogue Scale
Glu	Glutamate
HADS	Hospital Anxiety and Depression Scale
HAMA-14	Hamilton Anxiety Rating Scale-14
HDRS-17	Hamilton Depression Rating Scale-17
HDT	Head-Down Tilt
HLU	Hindlimb Unloading
IBD	Inflammatory Bowel Disease
IBS	Irritable Bowel Syndrome
IPAQ	International Physical Activity Questionnaire
ipRGCs	Intrinsically Photosensitive Retinal Ganglion Cells
ISI	Insomnia Severity Index
ISS	International Space Station
LED	Light-Emitting Diode
LEIDS-R	Leiden Index of Depression Sensitivity-Revised
LIR	Lymphocyte Irradiation Response
LOT-R	Life Orientation Test-Revised
MDA	Malondialdehyde
MEQ	Morningness–Eveningness Questionnaire
MGBA	Microbiota–Gut–Brain Axis
MPSs	Microphysiological Systems
NASA	National Aeronautics and Space Administration
NSBRI	National Space Biomedical Research Institute
OSA	Obstructive Sleep Apnea
PASA	Post-Acute Stress Assessment
PBPK	Physiologically Based Pharmacokinetic
PD	Pharmacodynamics
PHQ	Patient Health Questionnaire
PK	Pharmacokinetics
POMS	Profile of Mood States
PSG	Polysomnography
PSQI	Pittsburgh Sleep Quality Index
PSS	Perceived Stress Scale
REM	Rapid Eye Movement
RCSQ	Richards–Campbell Sleep Questionnaire
SAS	Self-Rating Anxiety Scale
SCFAs	Short-Chain Fatty Acids
SCN	Suprachiasmatic Nucleus
SDS	Self-Rating Depression Scale
SF-36	36-Item Short Form Health Survey
SOD	Superoxide Dismutase
SRI	Stress Response Inventory
SRSS	Self-Rating Sleep Scale
SSLA	Solid-State Lighting Assemblies
STAI	State–Trait Anxiety Inventory
SWS	Slow-Wave Sleep
TCI	Temperament and Character Inventory
TCM	Traditional Chinese Medicine
USP	United States Pharmacopeia
VAS	Visual Analogue Scale
VSH	Verran Snyder–Halpern Sleep Scale
WASO	Wake After Sleep Onset