Experimental fMRI Study of Guanfacine and Lisdexamfetamine in ADHD Adolescents (AGUALIS)

August 10, 2026 updated by: King's College London

Experimental fMRI Study on the Comparison of the Brain Function Effects of a Single Dose of Guanfacine and Lisdexamfetamine Relative to Placebo in Children and Adolescents With ADHD.

This is not a clinical trial. The aim of this study is to understand the mechanism of action of two recently licensed drugs for ADHD on brain function. The investigators will compare the brain activation changes elicited by Guanfacine extended release (GXR; a non-stimulant drug) with the brain activation changes elicited by Lisdexamfetamine (LISDEX; a stimulant drug) and by placebo in 20 drug-free patients with ADHD using functional Magnetic Resonance Imaging (fMRI). For this purpose the investigators intend to scan participants during their performance of tasks of attention, working memory, and inhibition, which the investigators know from previous studies to elicit abnormal brain activation patterns in ADHD patients (Rubia et al., 2005; Smith et al., 2006).

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Twenty ADHD patients between 8 and 20 years of age will participate in the double-blind, randomised, active drug condition, within-group, placebo-controlled experimental fMRI study. Each participant will be assessed in baseline measures during a pre-assessment visit. Then the patient will be scanned 3 times under each of these 3 drug conditions: GXR, LISDEX, and placebo. Every patient will receive a single typical clinical weight-adjusted dose of GXR (0.05mg/kg rounded down to the closest dose of 1mg, 2mg, or a maximum of 3mg), LISDEX (for participants aged 8-9 years 20mg regardless of weight; for participants aged 10-20 years the dose will be calculated at 0.5mg/kg rounded to the closest 30, 40, or 50mg, middle doses, e.g. 35mg, will be rounded down) and placebo (10mg Vit C) in one of the scans, in a randomised order. Patients will perform a battery of cognitive tests 3.5 hours after drug administration, after which the will undergo an fMRI scan. The scan will start 4.5 hours after drug administration where drugs have shown to have maximum plasma concentration. Participants will be scanned 3 times, one week apart, under each drug condition.

Substantial amendment submitted on 11/09/2019 regarding dosage:

Lowering the dose of lisdexamfetamine

The investigators had two participants who experienced transient minor adverse events after the single dose of Lisdexamfetamine.Therefore, the investigators have decided to lower the doses of lisdexamfetamine given in this study. Our original doses of lisdexamfetamine (30mg for participants under 30kg of body weight, 50mg for participants over 30kg of body weight) were weight adjusted and based on consultations with child psychiatrists, as well as on published studies using single doses of lisdexamfetamine. IN view of the adverse events our expert in paediatric psychopharmacology, Prof Paramala Santosh, has recommended the following rules for determining dosages of lisdexamfetamine in order to avoid any more adverse events:

  • Ages 8-9 years - will receive 20mg (regardless of weight)
  • Ages 10-20 years - will receive a minimum dose of 30mg or if higher than 60kg, a weight-adjusted dose at 0.5mg/kg which will be rounded down to the closest 30, 40, or 50mg (middle doses, e.g. 35mg, will be rounded down). The maximum dose will always be 50mg.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
25

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United Kingdom
      • London, United Kingdom, SE5 8AF
        • Institute of Psychiatry, Psychology & Neuroscience; King's College London

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

8 years to 20 years (Child, Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Age range: 8-20 years
  • Medication-naïve or non-medicated for two weeks or on stimulant medication, and willing to take the medication off for 48 hours before scans.
  • Meeting DSM-5 diagnosis of ADHD
  • Score above clinical cut-off on the ADHD module of the Kiddie Schedule for Affective Disorders and Schizophrenia (K-SADS) (Kaufman et al., 1997)
  • Score above clinical cut-off for ADHD on the short forms of the Conners Parent Rating Scales, CPRS (Conners et al., 2008)
  • Score above cut-off on the ADHD Rating Scale, ADHD-RS (DuPaul, et al., 1998)
  • IQ > 70 as tested on the WASI-II (Wechsler et al., 1999)
  • Mood and depression symptoms will be allowed as long as they are not the primary diagnosis.

Exclusion Criteria:

  • IQ < 70 (Wechsler et al., 1999).
  • Comorbidity with schizophrenia, bipolar disorder, learning disability, OCD, severe depression with current suicidal behaviour (as assessed by a clinical interview)
  • Neurological problems, i.e. a history of severe neurological illness, e.g. brain tumour, epilepsy or a history of symptomatic seizures, polyneuropathy etc.
  • Substance abuse history
  • Other illness (cardiovascular, renal, hepatic, metabolic) that would impact the data integrity or safety of the subject (i.e. contraindicated to any of the treatments) as determined by the investigators
  • Contraindication to MRI. i.e., previous implantation of metallic material, pacemaker, implanted medication pumps, neural stimulators, claustrophobia
  • Unable to give informed assent or consent in the case of the parent
  • Contraindications for LISDEX and GXR use (i.e. advanced arteriosclerosis, agitated states, hyperexcitability, hyperthyroidism, moderate or severe hypertension, symptomatic cardiovascular disease)

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Active Comparator: Lisdexamfetamine - Placebo
Drug: Lisdexamfetamine dimesylate
Lisdexamfetamine dimesylate (30mg for smaller, 50mg for larger boys) tablet
Other Names:
  • Vyvanse (Shire Pharmaceuticals Ltd.)
Drug: Placebo
Vitamin C (10mg) tablet
Active Comparator: Guanfacine - Placebo
Drug: Placebo
Vitamin C (10mg) tablet
Drug: Guanfacine Extended Release Oral Tablet
Guanfacine Extended Release (0.05mg/kg) tablet
Other Names:
  • Intuniv (Shire Pharmaceuticals Ltd.)
Experimental: Lisdexamfetamine - Guanfacine
Drug: Lisdexamfetamine dimesylate
Lisdexamfetamine dimesylate (30mg for smaller, 50mg for larger boys) tablet
Other Names:
  • Vyvanse (Shire Pharmaceuticals Ltd.)
Drug: Guanfacine Extended Release Oral Tablet
Guanfacine Extended Release (0.05mg/kg) tablet
Other Names:
  • Intuniv (Shire Pharmaceuticals Ltd.)

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change in brain activation under the three drug conditions (LISDEX, GXR, placebo)
Time Frame: 2 weeks (3 hourly scans one week apart)

Brain activation as measured by blood-oxygen-level-dependent (BOLD) response obtained by fMRI for each of the 3 below listed tasks and functional connectivity measures for the resting state scan.

  1. A working memory task (N-back)
  2. A tracking stop task
  3. A parametric sustained attention task
2 weeks (3 hourly scans one week apart)

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Changes in dependent variables extracted from performance on the fMRI tasks used under the three drug conditions (LISDEX, GXR, placebo)
Time Frame: 2 weeks (3 hourly scans one week apart)
  1. A working memory task (N-back)
  2. A tracking stop task
  3. A parametric sustained attention task
2 weeks (3 hourly scans one week apart)
Changes in dependent variables extracted from performance on a task battery outside the MRI scanner
Time Frame: 2 weeks (3 sessions one week apart)
Gonogo task, Simon task, Continuous performance task, Vigilance task, Time Discrimination task
2 weeks (3 sessions one week apart)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
King's College London

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Takeda
Shire

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Katya Rubia, PhD, King's College London

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
October 1, 2018

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
September 6, 2024

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
September 7, 2024

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
October 31, 2017

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 3, 2017

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
November 7, 2017

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
August 12, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 10, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
August 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • PCCWUAR

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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