Effect of dopamine on learning and cognition

Effects of Acute Levodopa Administration on Learning and Cognition in Healthy Adults: A Randomised, Double-Blind, Placebo-Controlled Study

Status

Not yet recruiting

Phases

Phase 1

Study type

Interventional

Source

ANZCTR

Registry ID

ACTRN12626000769381

Enrollment

300

Registered

2026-06-26

Start date

2026-07-06

Completion date

2030-12-31

Last updated

2026-07-13

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

None listed

Brief summary

This study has undergone initial ethics review by the Edith Cowan University Human Research Ethics Committee and is currently under revision. Once revised and approved, it will be approved under the following ethics protocol number REMS No. 2025-07121-LEOW. Participants are healthy adults recruited voluntarily via the ECU and Curtin University SONA participant pools, campus flyers, and community advertising. Informed consent is obtained after participants have had unlimited time to review the Participant Information Letter and ask questions. A pre-screening questionnaire is completed prior to scheduling to ensure participant safety; participants are not required to specify which exclusion criteria apply to them, protecting privacy. All data are de-identified upon collection, stored on secure password-protected university servers, and retained for a minimum of 15 years in accordance with ECU's Data Management Policy for clinical trials.

Interventions

Oral administration of a single dose of Madopar (100 mg levodopa / 25 mg benserazide) or placebo, administered in a randomised, double-blind design. Madopar is a dopamine precursor that increases dopamine availability in the brain. Placebo will be a vitamin C tablet. Dose: Madopar (100mg levodopa / 25 mg benserazide) Duration of treatment: single dose, one session. Adherence ensured by supervised in-person ingestion. Mode of delivery: Oral tablet (crushed tablet dispersed in orange juice)

Study design

Allocation

Randomised controlled trial

Intervention model

Parallel

Primary purpose

Treatment

Masking

Blinded (masking used)

Eligibility

Sex/Gender

All

Age

18 Years to No maximum

Healthy volunteers

Yes

Inclusion criteria

Aged 18 years or older Neurologically intact No current or past diagnosis of neurological or psychiatric conditions

Exclusion criteria

Current use of psychoactive medications or substances (including antidepressants, ADHD medications, anti-anxiety medications, sedatives, or recreational drugs) History of neurological conditions (e.g. Parkinson's disease, epilepsy, stroke, traumatic brain injury) History of psychiatric conditions (e.g. depression, anxiety, bipolar disorder, schizophrenia) History of heart problems or uncontrolled cardiovascular conditions Current use of medications that alter blood pressure or interact with MAO inhibitors Pregnant or breastfeeding Consumption of nicotine, energy drinks, or excessive caffeine (>250 mg) on the day of Madopar consumption Inability or unwillingness to complete study procedures

Outcome results