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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Retrospectively registered

Titles & IDs
Public title
Neurochemical and physiological mechanisms of executive control in healthy males
Scientific title
The effect of methylphenidate, atomoxetine and citalopram versus placebo on behavioural and physiological indices of executive control in healthy individuals.
Secondary ID [1] 280722 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Attention deficit hyperactivity disorder (ADHD) 237306 0
Condition category
Condition code
Mental Health 239629 239629 0 0
Other mental health disorders
Mental Health 239663 239663 0 0
Studies of normal psychology, cognitive function and behaviour

Study type
Description of intervention(s) / exposure
Methylphenidate (30mg), atomoxetine (60mg), citalopram (30mg).

All administered as capsules. Participants will be tested over four sessions, administered one dose of one drug (or placebo) each session. Sessions are a minimum of one week apart to allow wash-out of drug.

This study implements a cross-over design, with each participant receiving each of the three drugs and placebo over four sessions (one drug or placebo per session).
Intervention code [1] 236982 0
Treatment: Drugs
Comparator / control treatment
Placebo (30mg sugar pill administered in a capsule identical to those used to administer drugs).
Control group

Primary outcome [1] 238415 0
Performance on standard cognitive tasks (flanker, visual oddball, continuous performance, stop-signal) and consequent neural activity as measured by electroencephalogram (EEG).
Timepoint [1] 238415 0
1.5 hours after drug administration.
Primary outcome [2] 238416 0
Performance on standard cognitive tasks (Stroop go/nogo) and consequent neural activation as measured by functional magnetic resonance imaging (fMRI).
Timepoint [2] 238416 0
1.5 hours after drug administration.
Secondary outcome [1] 244894 0
Computer-based behavioural task performance (response time, sustained attention to response task) with no imaging or recording.
Timepoint [1] 244894 0
Directly after functional magnetic resonance imaging session.

Key inclusion criteria
Male, right-handed, Caucasian, non-smoker, normal or corrected-to-normal vision
Minimum age
18 Years
Maximum age
45 Years
Can healthy volunteers participate?
Key exclusion criteria
Smoker, abnormal vision, history of drug abuse, current recreational drug use, head injury resulting in unconsciousness, history of depression, history of anxiety, history of ADHD, history of psychosis, currently on other medication.

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
This is a repeated-measures design study. Participants will receive each drug or placebo once over four sessions. The order in which the drugs/placebo will be administered to each participant is randomised and structured by a Latin square design, and this drug order is sent directly to an offsite pharmacy that will be organising the drugs. The pharmacy will put each drug dose or placebo into identical capsules which will then be put into sealed opaque numbered envelopes, with the participant number (1-36) and session number (1-4) specified on the front.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Simple randomisation using computerised sequence generation.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?

Intervention assignment
Other design features
Phase 4
Type of endpoint(s)
Statistical methods / analysis

Recruitment status
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)

Funding & Sponsors
Funding source category [1] 237366 0
Government body
Name [1] 237366 0
Address [1] 237366 0
National Health and Medical Research Council
GPO Box 1421
Canberra ACT 2601
Country [1] 237366 0
Primary sponsor type
Queensland Brain Institute, University of Queensland
QBI Building (79)
St Lucia, QLD 4072
Secondary sponsor category [1] 236861 0
Name [1] 236861 0
School of Psychology, University of Queensland
Address [1] 236861 0
McElwain Building
The University of Queensland
St Lucia, QLD 4072
Country [1] 236861 0

Ethics approval
Ethics application status

Brief summary
The purpose of this study is to determine how three different medications influence brain activity whilst healthy participants are performing cognitive tasks. The three medications are methylphenidate, atomoxetine and citalopram. The first two medications are commonly used to treat attention deficit hyperactivity disorder (ADHD) in both children and adults, whereas citalopram is used to treat depression in adults. Importantly, we know that these medications act on different chemical systems in the brain. What we do not know, however, is whether these medications can influence underlying brain activity when people are performing cognitive tasks. This project will help us to understand which chemicals in the brain modulate our ability as humans to inhibit and control our behaviour. Studying these effects in healthy people will provide important clues to the underlying biology of a range of mental disorders where problems of inhibition and control of behaviour are common.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 29934 0
Address 29934 0
Country 29934 0
Phone 29934 0
Fax 29934 0
Email 29934 0
Contact person for public queries
Name 13181 0
Associate Professor Mark Bellgrove
Address 13181 0
Queensland Brain Institute
QBI Building (79)
St Lucia, QLD 4072
Country 13181 0
Phone 13181 0
+61 7 33656516
Fax 13181 0
+61 7 33654466
Email 13181 0
Contact person for scientific queries
Name 4109 0
Associate Professor Mark Bellgrove
Address 4109 0
Queensland Brain Institute
QBI Building (79)
St Lucia, QLD 4072
Country 4109 0
Phone 4109 0
+61 7 33656516
Fax 4109 0
+61 7 33654466
Email 4109 0

No information has been provided regarding IPD availability
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary