TRD	Treatment-resistant depression
MDD	Major depressive disorder
SSRIs	Selective serotonin reuptake inhibitors
SNRIs	Serotonin–norepinephrine reuptake inhibitors
MAOIs	Monoamine oxidase inhibitors
TCAs	Tricyclic antidepressants
IV	Intravenous
IM	Intramuscular
NMDA	N-methyl-D-aspartate
AMPA	α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid
BDNF	Brain-derived neurotrophic factor
mTOR	Rapamycin
CBT	Cognitive Behavioral Therapy
HPA	Hypothalamic–pituitary–adrenal
IL-6	Interleukin-6 (IL-6)
TNF-α	Tumor necrosis factor-alpha
PTSD	Post-traumatic stress disorder
KAP	Ketamine-assisted psychotherapy
KIC	Ketamine-induced cystitis
GAG	Glycosaminoglycan
ANCOVA	Analysis of covariance