AA	anthranilic acid
AhR	aryl hydrocarbon receptor
AMPA	α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid
APC	antigen-presenting cell
ASD	autism spectrum disorder
ATP	adenosine triphosphate
BBB	blood-brain barrier
BD	bipolar disorder
CA	cinnabarinic acid
CCBL	cysteine conjugate beta-lyase
CNS	central nervous system
CRP	C-reactive protein
CSF	cerebrospinal fluid
CUD	cocaine use disorder
DSM-5	Diagnostic and Treatment Manual for Mental Disorders, Fifth Edition
EEG	electroencephalography
FEP	first-episode psychosis
GAD	generalized anxiety disorder
GPR35	G-protein coupled receptor 35
3-HAA	3-hydroxyanthranilic acid
3-HK	3-hydroxy-kynurenine
HD	Huntington’s disease
HRQL	Health-Related Quality of Life
5-HT	serotonin, 5-hydroxytryptamine
IDO	indoleamine 2,3-dioxygenase
IFN	interferon
IL	interleukin
iNKT	invariant natural killer cell
KATs	kynurenine aminostransferase
KMO	kynurenine 3-monooxygenase
KP	kynurenine pathway
KYN	kynurenine
KYNA	kynurenic acid
LGI	low-grade inflammation
MCP	monocyte chemoattractant protein
MDD	major depressive disorder
MS	multiple sclerosis
MT	melatonin
NAD+	nicotinamide adenine dinucleotide
NADPH	nicotinamide adenosine dinucleotide phosphate
NK	natural killer cell
PD	Parkinson’s disease
PIC	picolinic acid
PTSD	post-traumatic stress disorder
QUIN	quinolinic acid
ROS	reactive oxygen species
SANS	Scale for the Assessment of Negative Symptoms
SCZ	schizophrenia
sIL-2R	soluble IL-2 receptor
SjS	Sjögren’s syndrome
SLE	systemic lupus erythematosus
SUD	substance use disorder
SWS	slow wave sleep
TDO	tryptophan 2,3-dioxygenase
Th1	T helper type 1
Th17	T helper type 17
Th2	T helper type 2
TNF	tumor necrosis factor
TRP	tryptophan
XA	xanthurenic acid