Trial reportJournal of psychopharmacology (Oxford, England)2019
The serotonin transporter gene-linked polymorphic region (5-HTTLPR) and the sleep-promoting effects of tryptophan: A randomized placebo-controlled crossover study.
Trial report in Journal of psychopharmacology (Oxford, England), 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 11 papers.
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Who cites it
11 citing papers in PubMed, 17 citations in OpenAlex.
- Role of the Amygdala in the Complex Relationship Between Sleep and Anxiety.International journal of molecular sciences · 2026Review
- Harnessing Dietary Tryptophan: Bridging the Gap Between Neurobiology and Psychiatry in Depression Management.International journal of molecular sciences · 2026Review
- Neurochemical Insights into the Role of Tryptophan Metabolites and Kynurenine Pathway in Insomnia and its Psychological and Neurological Comorbidities.Molecular neurobiology · 2025Review
- Comparative Study on Sedative and Hypnotic Effects of Crude and Parched Semen Ziziphi Spinosae: Integration of Network Pharmacology andCurrent computer-aided drug design · 2025Article
- Effect of graduated drug therapy for moderate-to-severe chronic insomnia on the severity of disease: an observational study in Germany.Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine · 2025Observational
- Why is vestibular migraine associated with many comorbidities?Journal of neurology · 2024Review
- Current Aspects of Selected Factors to Modulate Brain Health and Sports Performance in Athletes.Nutrients · 2024Review
- Circadian Rhythms and Sleep Disorders Associated to Major Depressive Disorder: Pathophysiology and Therapeutic Opportunities.CNS & neurological disorders drug targets · 2024Review
- Evaluation of the pharmacological effects and exploration of the mechanism of traditional Chinese medicine preparation Ciwujia tablets in treating insomnia based on ethology, energy metabolism, and urine metabolomic approaches.Frontiers in pharmacology · 2022Article
- A Cross-Sectional Study on the Relationship Among Cytokines, 5-HT2A Receptor Polymorphisms, and Sleep Quality of Non-manual Workers in Xinjiang, China.Frontiers in psychiatry · 2022Article
- Mechanisms Underlying the Action of Ziziphi Spinosae Semen in the Treatment of Insomnia: A Study Involving Network Pharmacology and Experimental Validation.Frontiers in pharmacology · 2021Article
Corrections and comments
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Authors and funding
2 authors at 1 institution in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundThe low-expressive short (S) allele of a functional polymorphism (5-HTTLPR) within the serotonin (5-hydroxytriptamine; 5-HT) transporter gene (SLC6A4) has been associated with a reduced functioning of the brain 5-HT system relative to the long (L) allele. As a consequence, the S-allele is found to predispose individuals to a higher risk of sleep quality reduction and clinical insomnia.
aimsThe present study investigated whether subchronic pre-sleep tryptophan administration could compensate for this predisposition by improving sleep in 5-HTTLPR S-allele carriers.
methodsIn a double-blind placebo-controlled crossover design a sample of homozygous 5-HTTLPR S-allele (
resultsThe results support the sleep-promoting effects of tryptophan. Tryptophan improved objective sleep efficiency and objective wake after sleep onset irrespective of allelic variation. There was a marginally significant improvement of subjective sleep quality in the 5-HTTLPR S-allele group but not in the L-allele group following tryptophan relative to placebo intake. In contrast, a significantly poorer sleep quality in the S-allele as opposed to the L-allele group in the placebo condition was not observed in the tryptophan condition.
conclusionsTryptophan augmentation promises to be a valuable treatment strategy for sleep impairments related to genetic deficiencies in 5-HT functioning.
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