ArticleBehavioral and brain functions : BBF2015
Serum concentrations of kynurenines in adult patients with attention-deficit hyperactivity disorder (ADHD): a case-control study.
Article in Behavioral and brain functions : BBF, 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 41 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
41 citing papers in PubMed, 56 citations in OpenAlex.
- Trial
- Trial
- Microbiome signatures correlate with diet-mediated ADHD symptom reduction.Gut microbes · 2026Article
- Kynurenine pathway dysregulation in attention-deficit hyperactivity disorder: Impact on N-methyl-D-aspartate receptors and phasic dopamine maturation.World journal of clinical pediatrics · 2026Review
- The potential role of kynurenine pathway and inflammation in pediatric obsessive-compulsive disorder with and without major depressive disorder comorbidity.Journal of neural transmission (Vienna, Austria : 1996) · 2026Article
- Linkage of kynurenine pathway metabolites to neuroinflammation in drug-naive children with attention-deficit/hyperactivity disorder: A cross-sectional, case-control study.World journal of clinical pediatrics · 2026Article
- Physiological levels of 3-hydroxykynurenine alter mitochondrial function and morphology in neuronal cells.bioRxiv : the preprint server for biology · 2026Article
- Article
- Tryptophan Metabolism in Neurodevelopment and Its Implications For Neurodevelopmental Disorders.Molecular neurobiology · 2025Review
- Disruption of gut microbiome and metabolome in treatment-naïve children with attention deficit hyperactivity disorder.BMC microbiology · 2025Article
- Serotonin dysfunction in ADHD.Journal of neurodevelopmental disorders · 2025Review
- Diverse Physiological Roles of Kynurenine Pathway Metabolites: Updated Implications for Health and Disease.Metabolites · 2025Review
- Exploring the Gut-brain Axis: Microbiome Contributions to Pathophysiology of Attention Deficit Hyperactivity Disorder and Potential Therapeutic Strategies.Current drug metabolism · 2025Review
- Is there a link between peripheral inflammation and blood brain barrier integrity in children with attention-deficit/hyperactivity disorder? A case-control study.BMC pediatrics · 2024Article
- Advancing Post-Stroke Depression Research: Insights from Murine Models and Behavioral Analyses.Life (Basel, Switzerland) · 2024Review
- The Biology and Biochemistry of Kynurenic Acid, a Potential Nutraceutical with Multiple Biological Effects.International journal of molecular sciences · 2024Review
- 4-Vinylpyridine copolymers for improved LC-MS tryptophan and kynurenine determination in human serum.Scientific reports · 2024Article
- Differences in the Interleukin Profiles in Inattentive ADHD Prepubertal Children Are Probably Related to Conduct Disorder Comorbidity.Biomedicines · 2024Article
- The Kynurenine Pathway in Attention-Deficit/Hyperactivity Disorder: A Systematic Review and Meta-Analysis of Blood Concentrations of Tryptophan and Its Catabolites.Journal of clinical medicine · 2024Review
- Kynurenine, Kynurenic Acid, Quinolinic Acid and Interleukin-6 Levels in the Serum of Patients with Autism Spectrum Disorder.Medicina (Kaunas, Lithuania) · 2023Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
7 authors at 2 institutions in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundThe essential amino acid tryptophan is catabolised mainly through the kynurenine pathway. Altered circulating levels of kynurenines have been reported in chronic inflammatory conditions and in several neuropsychiatric disorders, including depression and schizophrenia. Candidate gene studies suggest that genes related to the kynurenine catabolism may be associated with attention-deficit hyperactivity disorder (ADHD). Additionally, ADHD patients often report comorbid depression or anxiety. In this study we investigated serum levels of kynurenines in Norwegian adult ADHD patients and adult controls.
methodsWe compared serum levels of tryptophan and the seven tryptophan metabolites kynurenine, kynurenic acid, anthranilic acid, 3-hydroxykynurenine, xanthurenic acid, 3-hydroxyanthranilic acid and quinolinic acid in 133 adult patients with ADHD and 131 adult controls (18-40 years). Riboflavin (vitamin B2), total vitamin B6 and the nicotine metabolite cotinine were also measured. Serum samples were analysed using mass spectrometry. Patients and controls reported comorbid disorders and past (childhood) and current ADHD symptoms using the Wender Utah Rating Scale (WURS) and the Adult ADHD Self-report Scale (ASRS). Logistic regression was used to calculate odds ratios for having an ADHD diagnosis for different serum levels of each metabolite. In addition, we used Spearman's correlation analysis to investigate the correlation between serum levels of tryptophan and kynurenines and ADHD symptom scores.
resultsLower serum concentrations of tryptophan [odds ratio 0.61 (95 % confidence interval 0.45-0.83)], kynurenic acid [0.73 (0.53-0.99)], xanthurenic acid [0.65 (0.48-0.89)] and 3-hydroxyanthranilic acid [0.63 (0.46-0.85)], and higher levels of cotinine [7.17 (4.37-12.58)], were significantly associated with ADHD. After adjusting for tryptophan levels, only 3-hydroxyanthranilic acid and cotinine remained significant. Lower levels of tryptophan and kynurenine were also found to be correlated with higher total ASRS score and higher total WURS score, when adjusting for smoking and age.
conclusionsOur results suggest that there may be differences in serum levels of tryptophan and kynurenines between adult ADHD patients and adult controls. Although our findings do not suggest a chronic immune activation in ADHD, the underlying mechanisms and possible clinical implications of the differences should be further explored.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.