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CompletedNCT05476549Updated Dec 11, 2023

Effects of Lemon Verbena Extract Supplementation in Sub-ADHD Children

An interventional study of Lemon verbena and Placebo in Behavior, Child and Cognitive Change, sponsored by Northumbria University. Completed at 1 site in United Kingdom. Open to participants aged 8 Years to 17 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2023-12-11.

Sponsored by Northumbria University · Not applicable, Interventional, and Basic science

Phase
Not applicable
Study type
Interventional
Enrollment
140
Allocation
Randomized
Ages
8 Years to 17 Years
Sex
All
01

Study summary

The aim of this study is to investigate the effects of 15 mg/kg lemon verbena, in comparison to placebo, on the attention deficit hyperactivity disorder (ADHD) type behaviour and cognitive function of children who do not have a diagnosis of ADHD, but who exhibit high scores (highest tertile) on ADHD behaviour parameters. Multiple aspects of mood will also be assessed.

The proposed randomised, double-blind, placebo-controlled, parallel groups design methodology will assess the psychological effects of 15 mg/kg lemon verbena extract and a matched placebo prior to and after 4 and 8 weeks of supplementation. The trial will utilise the COMPASS cognitive assessment system (Northumbria University) and a range of mood measures during laboratory testing visits.

Parents and children will also take part in a concomitant smartphone study, comprising the collection of the parent's assessment of the child's behaviour/cognitive function and the child's self-report of the same, plus their mood. These assessments will take place on Days -1, 14, 28, 42 and 56.

02

Conditions studied

  • Behavior, Child
  • Cognitive Change
03

In context

Lead sponsor

Northumbria University is the lead sponsor of 156 studies on the registry; 22 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
8 Years to 17 Years
Sexes eligible
All
Accepts healthy volunteers
Yes

Eligibility criteria

Inclusion Criteria:

  • Are in good health as reported by themselves and their parent/guardian
  • Are aged 8 to 17 years at the time of giving assent and parents giving consent
  • Have a sex and age-related BMI less than the 98th centile according to the local NHS guidelines
  • Are rated by their parents as having a high score (T score of ≥60) on both the Connors 3 subscales of Inattention and Hyperactivity/Impulsivity.
  • Have no current diagnosis of ADHD
  • Have no relevant food intolerances/ sensitivities/ allergies
  • Are not currently using any illicit, herbal or recreational drugs including alcohol and nicotine products
  • Are not currently taking prescription medications
  • Have not taken dietary supplements e.g. Vitamins, omega 3 fish oils etc. in the last 4 weeks
  • Do not have a diagnosed neurological condition, or learning/behavioural or neurodevelopmental differences (e.g. dyslexia, autism)
  • Do not suffer from visual (including colour blindness) impairment that cannot be corrected with glasses or lenses (that may impact task performance in the opinion of the PI).
  • Do not have any pre-existing diagnosed medical condition/illness which will impact taking part in the study
  • Consume less than 250 mg/day of caffeine.
  • Can complete all of the study assessments at the training visit
  • Are not currently participating in other clinical or nutrition intervention studies, or have in the past 4 weeks
  • Are compliant with regards to treatment consumption
  • Have not taken antibiotics within the past 4 weeks
  • Do not have any health condition that would prevent fulfilment of the study requirements (this includes non-diagnosed conditions for which no medication may be taken)
05

Study design

Phase
Not applicable
Primary purpose
Basic science
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Quadruple (Participant, Care provider, Investigator, Outcomes assessor)
Enrollment
140 participants (actual)

Study arms

  • Experimental
    Lemon verbena

    Dietary Supplement: Lemon verbena

  • Placebo comparator
    Placebo

    Dietary Supplement: Placebo

Interventions

  • Dietary supplementLemon verbena

    Lemon verbena supplement administered at an estimated daily dose of 15mg/kg

  • Dietary supplementPlacebo

    Placebo supplement containing carrier material only

06

What researchers measure

Primary outcomes

  1. Change in Conners 3 score from baseline to 8 weeks, parent rating

    Time frame: Baseline to 8 weeks

  2. Change in Conners 3 score from baseline to 8 weeks, child rating

    Time frame: Baseline to 8 weeks

  3. Change in total mood disturbance from baseline to 8 weeks

    Profile of mood states questionnaire

    Time frame: Baseline to 8 weeks

  4. Change in depression-dejection from baseline to 8 weeks

    Profile of mood states questionnaire

    Time frame: Baseline to 8 weeks

  5. Change in tension-anxiety from baseline to 8 weeks

    Profile of mood states questionnaire

    Time frame: Baseline to 8 weeks

  6. Change in anger-hostility from baseline to 8 weeks

    Profile of mood states questionnaire

    Time frame: Baseline to 8 weeks

  7. Change in confusion-bewilderment from baseline to 8 weeks

    Profile of mood states questionnaire

    Time frame: Baseline to 8 weeks

  8. Change in vigour-activity from baseline to 8 weeks

    Profile of mood states questionnaire

    Time frame: Baseline to 8 weeks

  9. Change in fatigue-inertia from baseline to 8 weeks

    Profile of mood states questionnaire

    Time frame: Baseline to 8 weeks

  10. Change in systolic blood pressure from baseline to 8 weeks

    Systolic blood pressure (mmHg)

    Time frame: Baseline to 8 weeks

  11. Change in diastolic blood pressure from baseline to 8 weeks

    Diastolic blood pressure (mmHg)

    Time frame: Baseline to 8 weeks

  12. Change in body temperature from baseline to 8 weeks

    Degrees Celsius

    Time frame: Baseline to 8 weeks

  13. Change in RMSSD during the performance of cognitive tasks from baseline to 8 weeks

    Root mean square of successive differences between normal heartbeats (RMSSD)

    Time frame: Baseline to 8 weeks

  14. Change in heart rate during the performance of cognitive tasks from baseline to 8 weeks

    Beats per minute

    Time frame: Baseline to 8 weeks

  15. Change in heart rate variability index during the performance of cognitive tasks from baseline to 8 weeks

    Heart rate variability index

    Time frame: Baseline to 8 weeks

  16. Change in pNN50 during the performance of cognitive tasks from baseline to 8 weeks

    pNN50 is the mean number of times per hour in which the change in consecutive normal sinus (NN) intervals exceeds 50 milliseconds.

    Time frame: Baseline to 8 weeks

  17. Change in stress index during the performance of cognitive tasks from baseline to 8 weeks

    The stress index is a measure of the ratio between the parasympathetic and sympathetic tone. intervals exceeds 50 milliseconds.

    Time frame: Baseline to 8 weeks

  18. Change in subjective anxiety from baseline to 8 weeks

    State-trait anxiety inventory (STAI) total score

    Time frame: Baseline to 8 weeks

  19. Change in subjective perceived stress from baseline to 8 weeks

    Perceived stress scale (PSS) total score

    Time frame: Baseline to 8 weeks

  20. Change in subjective mood from baseline to 8 weeks, alertness

    Visual analogue scale composite score

    Time frame: Baseline to 8 weeks

  21. Change in subjective mood from baseline to 8 weeks, stress

    Visual analogue scale composite score

    Time frame: Baseline to 8 weeks

  22. Change in subjective mood from baseline to 8 weeks, tranquility

    Visual analogue scale composite score

    Time frame: Baseline to 8 weeks

  23. Change in speed of performance from baseline to 8 weeks

    Cognitive task composite score, milliseconds

    Time frame: Baseline to 8 weeks

  24. Change in accuracy of performance from baseline to 8 weeks

    Cognitive task composite score, %

    Time frame: Baseline to 8 weeks

  25. Change in accuracy of performance on arrow flankers task from baseline to 8 weeks

    Cognitive task score, %

    Time frame: Baseline to 8 weeks

  26. Change in accuracy of performance on numeric working memory task from baseline to 8 weeks

    Cognitive task score, %

    Time frame: Baseline to 8 weeks

  27. Change in accuracy of performance on Stroop task from baseline to 8 weeks

    Cognitive task score, %

    Time frame: Baseline to 8 weeks

  28. Change in accuracy of performance on Corsi blocks task from baseline to 8 weeks

    Cognitive task score, %

    Time frame: Baseline to 8 weeks

  29. Change in accuracy of performance on rapid visual information processing task from baseline to 8 weeks

    Cognitive task score, %

    Time frame: Baseline to 8 weeks

  30. Change in accuracy of performance on peg and ball task from baseline to 8 weeks

    Cognitive task score, number of errors

    Time frame: Baseline to 8 weeks

  31. Change in reaction time of performance on arrow flankers task from baseline to 8 weeks

    Cognitive task score, reaction time in milliseconds

    Time frame: Baseline to 8 weeks

  32. Change in reaction time of performance on numeric working memory task from baseline to 8 weeks

    Cognitive task score, reaction time in milliseconds

    Time frame: Baseline to 8 weeks

  33. Change in reaction time of performance on Stroop task from baseline to 8 weeks

    Cognitive task score, reaction time in milliseconds

    Time frame: Baseline to 8 weeks

  34. Change in reaction time of performance on rapid visual information processing task from baseline to 8 weeks

    Cognitive task score, reaction time in milliseconds

    Time frame: Baseline to 8 weeks

  35. Change in false alarms on rapid visual information processing task from baseline to 8 weeks

    Cognitive task score, number of false alarms

    Time frame: Baseline to 8 weeks

  36. Change in completion time of peg and ball task from baseline to 8 weeks

    Cognitive task score, time in milliseconds

    Time frame: Baseline to 8 weeks

  37. Change in thinking time of peg and ball task from baseline to 8 weeks

    Cognitive task score, time in milliseconds

    Time frame: Baseline to 8 weeks

07

Study locations

1 site
  • Brain, Performance, Nutrition Research Centre, Northumbria University
    Newcastle upon Tyne, Tyne & Wear NE1 8ST, United Kingdom
08

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Dec 11, 2023, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
09

Registry details

Key details

Study ID
NCT05476549
Lead sponsor
Northumbria University
Collaborators
Finzelberg GmbH
Responsible party
Sponsor
First posted
Jul 27, 2022
Start date
Aug 4, 2022
Primary completion
Aug 27, 2023
Completion
Aug 27, 2023
Last update
Dec 11, 2023

Study contacts

Philippa Jackson, PhD
principal investigator · Northumbria University

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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