5-HT2A	5-HT2A receptor (serotonin)
5-HT2C	5-HT2C receptor (serotonin)
5-HT3	5-HT3 receptor (serotonin)
ACR	American College of Rheumatology
AC	Adenylyl cyclase
ACTH	Adrenocorticotropic hormone
ASIC	Acid-sensing ion channel
CAM	Complementary and alternative medicine
cAMP	Cyclic adenosine monophosphate
CB1	Cannabinoid receptor 1
CB2	Cannabinoid receptor 2
CBD	Cannabidiol
CD19	Cluster of differentiation 19
CD4	Cluster of differentiation 4
CGRP	Calcitonin gene-related peptide
CNS	Central Nervous System
D2	Dopamine receptor D2
DAG	Diacylglicerol
DOR	δ-opioid receptor
DYN	Dynorphin
ENK	Enkephalin
ERK	Extracellular signal-regulated kinase
EULAR	European Alliance of Associations for Rheumatology
FDA	Food and Drug Administration
FIQ	Fibromyalgia Impact Questionnaire
fMRI	Functional magnetic resonance imaging
GABA	γ-aminobutyric acid
GIRK	G protein-coupled inward rectifying potassium channel
GPCR	G protein-coupled receptor
HPA	Hypothalamic-pituitary-adrenal axis
IBS	Inflammatory bowel disease
IFN-γ	Interferon gamma
IL-10	Interleukin 10
IL-17	Interleukin 17
IL-6	Interleukin 6
IL-8	Interleukin 8
IP3	Inositol triphosphate
KOR	κ-opioid receptor
LDN	Low-dose naltrexone
Leu-ENK	Leu-enkephalin
M1	M1 phenotype macrophage
M2	M2 phenotype macrophage
MAPK	Mitogen-activated protein kinase
Met-ENK	Met-enkephalin
MOR	μ-opioid receptor
MYT1L	Myelin transcription factor 1 like
NMDA	N-methyl-D-aspartate
NGF	Nerve growth factor
NRI	Selective noradrenaline reuptake inhibitor
NRXN3	Neurexin 3
OPRD1	Opioid receptor delta 1
OPRK1	Opioid receptor kappa 1
OPRM1	Opioid receptor mu 1
P2X3	P2X purinergic receptor type 3
PBMC	Peripheral blood mononuclear cell
PC	Prohormone convertase
PDYN	Prodynorphin
PENK	Proenkephalin
PKA	Protein kinase A
PLC	Phospholipase C
PNS	Peripheral Nervous System
POMC	Proopiomelanocortin
RCT	Randomized controlled trial
RLS	Restless legs syndrome
ROS	Reactive oxygen species
SLC6A4	Solute carrier family 6 member 4
SNP	Single nucleotide polymorphism
SNRI	Serotonin and noradrenaline reuptake inhibitor
SOD	Superoxide dismutase
SSRI	Selective serotonin reuptake inhibitor
TCA	Tricyclic antidepressant
TGF-β	Transforming growth factor beta
THC	Tetrahydrocannabinol
TNF-α	Tumor necrosis factor alpha
TRPV	Transient receptor potential vanilloid
TRPV1	Transient receptor potential vanilloid 1
TRPV2	Transient receptor potential vanilloid 2
VGCC	Voltage-gated calcium channel
α-MSH	α-melanocyte-stimulating hormone
β-END	β-endorphin
β-LPH	β-lipotropin
γ-LPH	γ-lipotropin
γ-MSH	γ-melanocyte-stimulating hormone