Effects of Lemon Verbena Extract Supplementation in Sub-ADHD Children

Effects of Lemon Verbena Extract Supplementation on Behaviour Mood and Cognitive Function in Sub-ADHD Children

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.

Study Overview

• Status: Completed
• Conditions: Cognitive Change; Behavior, Child
• Intervention / Treatment: Dietary supplement: Lemon verbena; Dietary supplement: Placebo

• Study Type: Interventional
• Enrollment (Actual): 140
• Phase: Not Applicable

Contacts and Locations

Study Locations

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

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 8 years to 17 years (Child)
• Accepts Healthy Volunteers: Yes

Description

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)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Placebo	Dietary supplement: Placebo; Placebo supplement containing carrier material only
Experimental: Lemon verbena	Dietary supplement: Lemon verbena; Lemon verbena supplement administered at an estimated daily dose of 15mg/kg

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Conners 3 score from baseline to 8 weeks, parent rating		Baseline to 8 weeks
Change in Conners 3 score from baseline to 8 weeks, child rating		Baseline to 8 weeks
Change in total mood disturbance from baseline to 8 weeks	Profile of mood states questionnaire	Baseline to 8 weeks
Change in depression-dejection from baseline to 8 weeks	Profile of mood states questionnaire	Baseline to 8 weeks
Change in tension-anxiety from baseline to 8 weeks	Profile of mood states questionnaire	Baseline to 8 weeks
Change in anger-hostility from baseline to 8 weeks	Profile of mood states questionnaire	Baseline to 8 weeks
Change in confusion-bewilderment from baseline to 8 weeks	Profile of mood states questionnaire	Baseline to 8 weeks
Change in vigour-activity from baseline to 8 weeks	Profile of mood states questionnaire	Baseline to 8 weeks
Change in fatigue-inertia from baseline to 8 weeks	Profile of mood states questionnaire	Baseline to 8 weeks
Change in systolic blood pressure from baseline to 8 weeks	Systolic blood pressure (mmHg)	Baseline to 8 weeks
Change in diastolic blood pressure from baseline to 8 weeks	Diastolic blood pressure (mmHg)	Baseline to 8 weeks
Change in body temperature from baseline to 8 weeks	Degrees Celsius	Baseline to 8 weeks
Change in RMSSD during the performance of cognitive tasks from baseline to 8 weeks	Root mean square of successive differences between normal heartbeats (RMSSD)	Baseline to 8 weeks
Change in heart rate during the performance of cognitive tasks from baseline to 8 weeks	Beats per minute	Baseline to 8 weeks
Change in heart rate variability index during the performance of cognitive tasks from baseline to 8 weeks	Heart rate variability index	Baseline to 8 weeks
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.	Baseline to 8 weeks
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.	Baseline to 8 weeks
Change in subjective anxiety from baseline to 8 weeks	State-trait anxiety inventory (STAI) total score	Baseline to 8 weeks
Change in subjective perceived stress from baseline to 8 weeks	Perceived stress scale (PSS) total score	Baseline to 8 weeks
Change in subjective mood from baseline to 8 weeks, alertness	Visual analogue scale composite score	Baseline to 8 weeks
Change in subjective mood from baseline to 8 weeks, stress	Visual analogue scale composite score	Baseline to 8 weeks
Change in subjective mood from baseline to 8 weeks, tranquility	Visual analogue scale composite score	Baseline to 8 weeks
Change in speed of performance from baseline to 8 weeks	Cognitive task composite score, milliseconds	Baseline to 8 weeks
Change in accuracy of performance from baseline to 8 weeks	Cognitive task composite score, %	Baseline to 8 weeks
Change in accuracy of performance on arrow flankers task from baseline to 8 weeks	Cognitive task score, %	Baseline to 8 weeks
Change in accuracy of performance on numeric working memory task from baseline to 8 weeks	Cognitive task score, %	Baseline to 8 weeks
Change in accuracy of performance on Stroop task from baseline to 8 weeks	Cognitive task score, %	Baseline to 8 weeks
Change in accuracy of performance on Corsi blocks task from baseline to 8 weeks	Cognitive task score, %	Baseline to 8 weeks
Change in accuracy of performance on rapid visual information processing task from baseline to 8 weeks	Cognitive task score, %	Baseline to 8 weeks
Change in accuracy of performance on peg and ball task from baseline to 8 weeks	Cognitive task score, number of errors	Baseline to 8 weeks
Change in reaction time of performance on arrow flankers task from baseline to 8 weeks	Cognitive task score, reaction time in milliseconds	Baseline to 8 weeks
Change in reaction time of performance on numeric working memory task from baseline to 8 weeks	Cognitive task score, reaction time in milliseconds	Baseline to 8 weeks
Change in reaction time of performance on Stroop task from baseline to 8 weeks	Cognitive task score, reaction time in milliseconds	Baseline to 8 weeks
Change in reaction time of performance on rapid visual information processing task from baseline to 8 weeks	Cognitive task score, reaction time in milliseconds	Baseline to 8 weeks
Change in false alarms on rapid visual information processing task from baseline to 8 weeks	Cognitive task score, number of false alarms	Baseline to 8 weeks
Change in completion time of peg and ball task from baseline to 8 weeks	Cognitive task score, time in milliseconds	Baseline to 8 weeks
Change in thinking time of peg and ball task from baseline to 8 weeks	Cognitive task score, time in milliseconds	Baseline to 8 weeks

Collaborators and Investigators

• Sponsor: Northumbria University
• Collaborators: Finzelberg GmbH
• Investigators: Principal Investigator: Philippa Jackson, PhD, Northumbria University

Study record dates

Study Major Dates

• Study Start (Actual): August 4, 2022
• Primary Completion (Actual): August 27, 2023
• Study Completion (Actual): August 27, 2023

Study Registration Dates

• First Submitted: July 25, 2022
• First Submitted That Met QC Criteria: July 25, 2022
• First Posted (Actual): July 27, 2022

Study Record Updates

• Last Update Posted (Estimated): December 11, 2023
• Last Update Submitted That Met QC Criteria: December 8, 2023
• Last Verified: December 1, 2023

More Information

Terms related to this study

• Other Study ID Numbers: 48CD1

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No