None listed
Conditions
Brief summary
This research thus aims to address these gaps in knowledge and practice by characterising how acute doses of Methylphenidate (Ritalin) affect ocular parameters and the visual attentional system. Furthermore, we seek to examine how these changes might be indexed to predict impairment in performance during a neurocognitive and driving task.
Interventions
Over the two-week experimental period, participants will receive all of the experimental doses.
One dose will be taken at each session [i.e. active Methylphenidate (Ritalin) or placebo Methylphenidate (Ritalin)] and the order of dosing will be randomised.
The active treatment is:
1. Methylphenidate (Ritalin) 10mg
The placebo treatments are:
1. Placebo tablet (identical in taste, texture, weight and smell). Microcellulose tablet
A one-week washout period will occur between testing sessions.
Over the two-week experimental period, participants will receive all of the experimental doses. One dose will be taken at each session [i.e. active Methylphenidate (Ritalin) or placebo Methylphenidate (Ritalin)] and the order of dosing will be randomised. The active treatment is: 1. Methylphenidate (Ritalin) 10mg The placebo treatments are: 1. Placebo tablet (identical in taste, texture, weight and smell). Microcellulose tablet A one-week washout period will occur between testing sessions. Prior to dosing at each testing visit (each at V1 and V2), participants will provide one saliva sample to screen for evidence of recent use of drugs [amphetamine/d-methamphetamine, 3,4- methylenedioxymethamphetamine (MDMA), cocaine, cannabis (del ta-9-tetrahydrocannabinol) and opiates] using the Securetec DrugWipe 6s device. This screening assessment requires an absorbent pad to be placed over the tongue for approximately 20 seconds. 1ml of saliva will be taken per sample, therefore approximately 4ml in total over each of the four experimental sessions. A sample volume of less than 10 micro litres is sufficient for analysis. The device is wiped on the tongue, when the colour has changed from pink to yellow there is the required amount of saliva to obtain the results. A registered research nurse trained in venepuncture or a qualified venepuncture technician will collect one blood samples at each testing session (each at V1, V2): after the final cognitive assessment. The CogTrack™ System will be used to assess the cognitive effects of the intervention. Three tasks will be used in this study to assess visual processing, processing speed and reaction/decision speed, specifically: Digit vigilance, Spatial working memory, Numeric working memory, Simple Reaction Time and Choice Reaction Time. Participants will be assessed at approximately 30 minutes post-dosing and at 2.5 hours post dosing. Driving performance will be assessed using the Forum 8 driving simulator, and driving performance will be assessed once per study session, for a 40 minute duration. The simulator consists of a car unit with adjustable car seats and a dashboard and includes a steering wheel, turn sign indicators, gear lever, brake and accelerator pedals for vehicle control. The system generates realistic roadway scenery which is presented on three integrated TV screens 1.90 meters in front of the centre of the steering wheel. The speed and gear number are displayed on the dashboard and screen. Auditory feedback is provided by speakers and included the sound of the engine, braking, speeding in curves, and driving off-road. Driving assessment will take place at approximately 1.5 hours post dosing.
Sponsors
Swinburne University of Technology
Study design
Allocation
Randomised controlled trial
Intervention model
Crossover
Primary purpose
Treatment
Masking
Blinded (masking used) (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
All
Age
21 Years to 45 Years
Healthy volunteers
Yes
Inclusion criteria
• Male or female, aged 21 to 45 years; • Less than 100kg in weight [due to expected metabolism rate of Methylphenidate (Ritalin®), 10mg]; • Willing and able to provide written informed consent; • Understands and is willing and able to comply with all study procedures; • Fluent in written and spoken English; • Must have normal or corrected-to-normal vision; • Is a regular driver (> 4,000 km/year) with three years of driving with a full driver’s licence; • Willing to abstain from the following prior to their scheduled visit: o No food or drinks (except water) within 2 hours prior to testing; o No caffeine-containing products within 12 hours prior to testing; o No alcohol within 24 hours prior to testing; o No medication for at least 1 week prior to testing (except for prophylactic antibiotics, contraceptive pill or other routine medications to treat benign conditions, such as antibiotics to treat acne); o No illicit substance use for one week prior to, and for the duration of the trial. o No driving or riding a bicycle or motorbike from the testing site; o No driving, riding, operating heavy machinery for 24 hours after leaving the site o No alcohol, drugs, or medication (unless consulted with doctor) for 24 hours after leaving the site.
Exclusion criteria
• Unable to understand or comply with testing procedures; • Inability to speak or read English; • History of drug or substance abuse or current illicit drug abuse; • History of neurological conditions or previous or current history of psychiatric, cardiac, endocrine, gastrointestinal, or bleeding disorders; • Pregnant, potentially pregnant or lactating; • Taking any form of ongoing medication (except for prophylactic antibiotics, contraceptive pill or other routine medications to treat benign conditions, such as antibiotics to treat acne); • Unable to participate in scheduled visit, treatment plan, tests and other study procedures according to the protocol; • Current participation in any other studies involving investigational or marketed products within 30 days prior to the screening visit; • Have previously participated in this study • Currently under administrative or legal supervision.
Outcome results
None listed