69 peer-reviewed studies · Evidence score: 8/10
Cheng YC et al. • Psychological medicine (2025)
This extensive systematic review and NMA of nutraceuticals for treating depressive disorders indicated a number of nutraceuticals that could offer benefits, either as adjuncts or monotherapies.
Almulla AF et al. • Cells (2022)
Patients with affective disorders with melancholic and psychotic features and suicidal behaviors showed normal IDO enzyme activity but a lowered availability of plasma/serum TRP to the brain, which is probably due to other processes such as low albumin levels.
Wang Z et al. • Drug and alcohol dependence (2023)
Our results suggested a shift in the tryptophan metabolism to the kynurenine pathway and a down-regulation of the potentially neuroprotective kynurenic acid in individuals with AUD.
Kikuchi AM et al. • Nutrients (2021)
Higher tryptophan intake was inversely associated with depression risk.
Hughes JR et al. • The Cochrane database of systematic reviews (2014)
The antidepressants bupropion and nortriptyline aid long-term smoking cessation.
Almulla AF et al. • Journal of Alzheimer's disease : JAD (2022)
AD is characterized by TRP depletion but not by an overactivity of the TRYCAT pathway.
Sutanto CN et al. • Nutrients (2022)
L-tryptophan supplementation at doses >= 1g improved overall sleep quality, particularly in subjects with existing sleep difficulties.
Liao Z et al. • Nutrients (2023)
This meta-analysis examined the effects of Acetyl-L-Carnitine.
Wang Y et al. • Journal of affective disorders (2024)
This systematic review delineated metabolic biomarkers and pathways related to depression in the murine and clinical samples, providing opportunities for early diagnosis of MDD and the development of novel diagnostic targets.
Tosti G et al. • Nutrients (2023)
The present meta-analysis shows, by pooling immunocompetent and immunosuppressed patients, that there is insufficient evidence that oral nicotinamide therapy significantly reduces the number of keratinocyte cancers.
Wang S et al. • Nutrients (2023)
Therefore, a network of intestinal tryptophan metabolism pathways in IBD could be established, helping to assess the potential of genes and metabolites involved in these pathways as diagnostic markers and targets for IBD management.
Suktas A et al. • BMC psychiatry (2024)
At least 13 studied genes with polymorphisms were involved in MDD development according to MF and BP, but not significantly.
Gallizzi AA et al. • Frontiers in immunology (2024)
Our review highlights the underestimated role of neutrophils and platelets in the pathological mechanisms of anaphylactic reactions.
De La Torre Canales G et al. • Journal of oral rehabilitation (2024)
The blood levels of tryptophan and its metabolites serotonin and kynurenine seem to influence chronic musculoskeletal pain.
Hebbrecht K et al. • Frontiers in immunology (2021)
The TRYCAT pathway appears to be downregulated in BD patients.
Saarto T et al. • The Cochrane database of systematic reviews (2005)
Antidepressants are effective for a variety of neuropathic pains.
Moncrieff J et al. • Molecular psychiatry (2023)
This meta-analysis examined the effects of Tryptophan.
Sutanto CN et al. • Nutrition reviews (2022)
Trp supplementation, especially at ≥1 g can help improve sleep quality.
Plitman E et al. • Schizophrenia bulletin (2017)
For permissions, please email: journals.permissions@oup.com.
Barrera-Hernández S et al. • Seminars in arthritis and rheumatism (2026)
Metabolomic profiling identifies a reproducible SLE signature: relative to controls, branched-chain (isoleucine, leucine) and aromatic (tryptophan) amino acids are lower, methionine is higher, and lipid profiles show higher oleic and lower capric acids, patterns consistent with impaired mitochondrial energetics and altered one-carbon flux.