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The Effect of 5-hydroxytryptophan on ADHD Traits and Eye Movements
Sponsor: University of Sheffield
Summary
The aim of this project is to look at the impact of 5-Hydroxytryptophan (5-HTP) on distractibility. 5-HTP is the precursor to the neurotransmitter serotonin and is a chemical that the body produces naturally. There is evidence that distractibility is associated with a decreased level of serotonin. This research aims to see if giving people 5-HTP will alter their distractibility, which will form part of an initial assessment as to whether 5-HTP could be used to support people with attention problems. The study involves completing a short survey about mental health and behaviours, and if eligible, participation in an in-person study at the University of Sheffield. The in-person session involves completing some cognitive tasks to look at eye movement, taking 5-HTP or a sugar tablet with no active ingredients, and then completing the tasks again after a 90-minute wait.
Official title: The Effect of 5-hydroxytryptophan on Microsaccades and Distractibility in Individual With High Levels of ADHD Traits: a Randomised, Double-blind Trial
Key Details
Gender
All
Age Range
18 Years - 65 Years
Study Type
INTERVENTIONAL
Enrollment
150
Start Date
2025-11-25
Completion Date
2027-06
Last Updated
2026-08-20
Healthy Volunteers
Yes
Conditions
Interventions
5-hydroxytryptophan (food supplement) 200mg
200mg 5-HTP delivered in two tablets. Tablets obtained from Nature's Best supplements. Each tablet contains 3982mg of Griffonia seed extract, providing 100mg of 5-HTP. The tablets consist of calcium carbonate, griffonia seed extract, Anti-caking Agents (Silicon Dioxide, Stearic Acid, \& Magnesium Stearate) and Tablet Coating (Hydroxypropyl Methylcellulose, Glycerol).
5-hydroxytryptophan (food supplement) 300mg
300mg 5-HTP delivered in three tablets. Tablets obtained from Nature's Best supplements. Each tablet contains 3982mg of Griffonia seed extract, providing 100mg of 5-HTP. The tablets consist of calcium carbonate, griffonia seed extract, Anti-caking Agents (Silicon Dioxide, Stearic Acid, \& Magnesium Stearate) and Tablet Coating (Hydroxypropyl Methylcellulose, Glycerol).
Placebo
Unmedicated lactose-sucrose tablets provided by Ainsworth's homoeopathic remedies
Locations (1)
University of Sheffield
Sheffield, South Yorkshire, United Kingdom