aB&D	Acidified Bligh and Dyer
B&D	Bligh and Dyer
CNS	Central nervous system
CSF	Cerebrospinal fluid
CV	Coefficient of variation
DOPAC	3,4-Dihydroxyphenylacetic acid
EMA	the European Medicines Agency
ESI	Electrospray ionization
FDA	the U.S. Food and Drug Administration
GABA	γ-Aminobutyric acid
GC-MS	Gas chromatography–mass spectrometry
GWAS	Genome-wide association studies
5-HIAA	5-Hydroxyindole-3-acetic acid
HILIC	Hydrophilic interaction liquid chromatography
HPLC/UPLC-MS	High-performance/ultra-high-performance liquid chromatography–mass spectrometry
HVA	Homovanillic acid
ICH M10	the International Council for Harmonization
LLOQ	Lower limit of quantification
LLE	Liquid–liquid extraction
LOD	Limit of detection
MHPG	3-Methoxy-4-hydroxyphenylglycol
MS	Mass spectrometry
MSI	the Metabolomics Standards Initiative
MS/MS	Tandem mass spectrometry
MWAS	Metabolome-wide association study
NMR	Nuclear magnetic resonance
PCR	Polymerase chain reaction
RP	Reversed-phase
TOF	Time-of-flight
Q	Quadrupole
QC	Quality control
QQQ	Triple-quadrupole
ULOQ	Upper limit of quantification