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Trial registered on ANZCTR


Registration number
ACTRN12624000645550p
Ethics application status
Submitted, not yet approved
Date submitted
16/04/2024
Date registered
20/05/2024
Date last updated
20/05/2024
Date data sharing statement initially provided
20/05/2024
Type of registration
Prospectively registered

Titles & IDs
Public title
Recollection of Event Memory following Drugs, Alcohol, and Stress
Scientific title
Recollection of Event Memory following Drugs, Alcohol, and Stress in Adults Who Have Used Substances Previously
Secondary ID [1] 311972 0
nil
Universal Trial Number (UTN)
Trial acronym
REMDAS
Linked study record

Health condition
Health condition(s) or problem(s) studied:
memory impairment 333577 0
Condition category
Condition code
Mental Health 330261 330261 0 0
Studies of normal psychology, cognitive function and behaviour

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
This trial uses a crossover study design where each participant will attend 3 sessions with a washout period of 1 week in between each session. Comparison will be made between alcohol (positive control) and placebo (negative control) with the substance of interest dexamfetamine (2omg oral tablet) across three experimental sessions. Participants will attend these sessions in a randomly assigned order, for example:
Visit 1: Amphetamine pills + Placebo alcohol
Visit 2: Placebo pills + Alcohol
Visit 3: Placebo pills + Placebo alcohol

The study also uses double dummy blinding, where participants will consume two substances (drinks and pills) in each session but will not know which is placebo and which is active, and in one session both substances will be placebo. There is no condition where both alcohol and amphetamine will be consumed in the same session. Participants will be instructed to abstain from alcohol and drugs for 24 hours, and from cigarettes, caffeine or eating for two hours before the sessions. At the beginning of each session, participants will be cannulated (for the blood tests), complete the demographics and drug history questionnaire, and receive a baseline blood and saliva test. Dexamfetamine/placebo pills will be administered by the study research nurse. Bloods will be taken across 4 time points each session to quantify plasma levels of substance.

The stress and memory tests will occur at each study visit. The stress test is the Maastricht Acute Stress Test which involves arm submersion in ice water, alongside a social threat (maths task while evaluated and filmed). Memory will be tested via recall of the MAST event (to-be-remembered items to be counterbalanced across session), the DRM word list task, and a face recognition task (employing the Chicago Face database). Memory and stress tests will occur approximately 30 minutes post substance administration. Salivary cortisol will be collected to quantify stress levels. These tasks will be completed by trained researchers.

Participants will remain on site until it is safe for them to leave as per standard clinical protocols (e.g., > 4 hours since dose, clinician review).
Intervention code [1] 328432 0
Treatment: Other
Comparator / control treatment
Positive control: Alcohol; vodka mixed with 100mL tonic water to reach average blood alcohol concentration (BAC) 0.08%; The alcohol placebo will be 100mL tonic water with the rim of the glass rubbed with alcohol, etc.

Negative control: placebo tablets designed to look the same as the dexamphetamine tablets. Placebo formulation includes: Microcrystalline Cellulose, Colloidal Silicon Dioxide, Sodium Starch Glycolate, Sodium Stearyl Fumarate.


Consumption is monitored by the research nurse to ensure adherence.
Control group
Placebo

Outcomes
Primary outcome [1] 338006 0
Recall memory under stress
Timepoint [1] 338006 0
Approx 45 mins post substance ingestion
Primary outcome [2] 338081 0
Recall and recognition memory
Timepoint [2] 338081 0
Approx 45 mins post substance ingestion
Primary outcome [3] 338082 0
Face recognition memory (visual)
Timepoint [3] 338082 0
Approx 45 mins post substance ingestion
Secondary outcome [1] 434102 0
Salivary cortisol
Timepoint [1] 434102 0
Repeated measures design over 3 time points; within session cortisol will be assessed via saliva at 3 time points: baseline, 35 mins post stressor, and 50 mins post stressor
Secondary outcome [2] 434429 0
Stress ratings
Timepoint [2] 434429 0
Assessed 6 times across session; 1 baseline, 1 approx 45 mins post MAST, 15 mins later, 15 mins later again, approx 3 hours later, and at discharge
Secondary outcome [3] 434430 0
Positive and Negative Affect Schedule (PANAS)
Timepoint [3] 434430 0
collected at baseline and approx 45 mins post stressor (MAST)
Secondary outcome [4] 434431 0
Amphetamine intoxication
Timepoint [4] 434431 0
6 time points: 45 mins post drug administration, 15 mins after that, 15 mins after that, then at approx 4pm (4 hours post drug administration), 30 mins after that, and at discharge (approx 5pm)
Secondary outcome [5] 434432 0
Alcohol intoxication
Timepoint [5] 434432 0
6 timepoints across study session: approx 45 mins post substance administration, 15 mins after that, 15 mins after that, 4pm, 4.30, 5pm (discharge)
Secondary outcome [6] 434433 0
Stress and pain responses to MAST: composite
Timepoint [6] 434433 0
Approx 45 mins post stressor
Secondary outcome [7] 434434 0
Stress via salivary alpha amylase
Timepoint [7] 434434 0
Approx 2 mins post stressor

Eligibility
Key inclusion criteria
1) Self-reported previous experience with the substance of interest but not current regular use. Regular use is defined as taking amphetamines for non-medical purposes more than once a week.
2) Adequate cognition and English to consent and complete the study. This will be determined by the researcher who administers the phone screening.
Minimum age
18 Years
Maximum age
65 Years
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
1) Current, clinically significant physical disease (e.g., cardiac, liver). The nurse or doctor associated with the study will make this determination based on an examination of the potential participant.
2) Severe psychiatric illness (i.e., schizophrenia, suicide risk). The nurse or doctor associated with the study will make this determination based on an examination of the potential participant.
3) Current substance use disorder other than nicotine. The nurse or doctor associated with the study will make this determination based on an examination of the potential participant and the diagnostic tools.
4) Previous hypersensitivity/adverse reaction to the studied drugs. We will evaluate this based on the potential participant’s self-report.
5) Current medication use that is a contraindication for the study drug or interferes with drug absorption. The nurse or doctor associated with the study will make this determination based on an examination of the potential participant. Stable antidepressant use for > one month will be permitted.
6) Oral-contraceptive use in females. We will evaluate this based on the potential participant’s self-report.
7) Current pregnancy/lactation. We will evaluate this based on the potential participant’s self-report in the first instance (phone screen) but also via pregnancy testing prior to study session commencement.
8) Women of child-bearing capacity who are not prepared to use (non-pharmacological) contraception during the study. We will evaluate this based on the potential participant’s self-report.

Study design
Purpose of the study
Educational / counselling / training
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Central randomisation by computer
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Permuted block randomisation
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s
The people administering the treatment/s
The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Crossover
Other design features
Phase
Not Applicable
Type of endpoint/s
Pharmacokinetics / pharmacodynamics
Statistical methods / analysis
Data analysis will primarily be conducted using SPSS and R. We plan to employ mixed repeated measures ANOVAs to assess main effects (alcohol vs amphetamine vs placebo) and interaction terms related to substance administration, memory performance, and response to stress status. This approach allows for a comprehensive examination of the effects of these factors on our variables of interest.

Recruitment
Recruitment status
Not yet recruiting
Date of first participant enrolment
Anticipated
17/06/2024
Actual
Date of last participant enrolment
Anticipated
17/06/2025
Actual
Date of last data collection
Anticipated
10/07/2025
Actual
Sample size
Target
90
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
NSW
Recruitment hospital [1] 26415 0
Royal North Shore Hospital - St Leonards
Recruitment postcode(s) [1] 42393 0
2065 - St Leonards

Funding & Sponsors
Funding source category [1] 316317 0
Government body
Name [1] 316317 0
Australian Research Council (ARC)
Country [1] 316317 0
Australia
Funding source category [2] 316318 0
Other
Name [2] 316318 0
Ramsay Health Care
Country [2] 316318 0
Australia
Primary sponsor type
University
Name
University of Sydney
Address
Country
Australia
Secondary sponsor category [1] 318501 0
None
Name [1] 318501 0
Address [1] 318501 0
Country [1] 318501 0

Ethics approval
Ethics application status
Submitted, not yet approved
Ethics committee name [1] 315131 0
Northern Sydney Local Health District Human Research Ethics Committee
Ethics committee address [1] 315131 0
https://www.nslhd.health.nsw.gov.au/Research/ResearchOffice/Pages/HREC.aspx
Ethics committee country [1] 315131 0
Australia
Date submitted for ethics approval [1] 315131 0
14/07/2023
Approval date [1] 315131 0
Ethics approval number [1] 315131 0

Summary
Brief summary
Understanding the effect of intoxication on witnesses is important to the legal system, but there are key gaps in our knowledge in this area. While the research on alcohol and memory is advancing (e.g., see Jores et al., 2019), there is still little known on other substance effects in an eyewitness context. Specifically, there is minimal research on amphetamines and event memory, and no known research on any type of amphetamines and their impact on face recognition in a line-up context. This leaves many remaining questions and gaps which this study aims to fill as itpertains to dosage, timing, expectancy effects (i.e., anticipating potential substance effects that influence performance). Furthermore, many crimes are distressing in nature, however minimal research has explored intoxication and memory in the context of a distressing event. The role of stress must also be addressed because stress hormones are released during amphetamine use. This requires research about whether stress and amphetamine intoxication combine to impact memory. Additionally, it is unclear whether alcohol use will reduce the stress response, or whether stress will lead to a pause in alcohol metabolism, and how either of these may interact with memory.

Study hypotheses: it is anticipated that alcohol may impair memory completeness but not accuracy, whereas it is possible that dexamfetamine may improve memory. An exploratory aim is to investigate whether stress impacts drug response (e.g., makes drug effects more or less pronounced and subsequently impacts memory accordingly).
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 133766 0
Dr Lauren Monds
Address 133766 0
Central Clinical School, Faculty of Medicine and Health, USYD; 92 Parramatta Rd, Camperdown, NSW, 2050
Country 133766 0
Australia
Phone 133766 0
+61 2 9036 3136
Fax 133766 0
Email 133766 0
[email protected]
Contact person for public queries
Name 133767 0
Lauren Monds
Address 133767 0
Central Clinical School, Faculty of Medicine and Health, USYD; 92 Parramatta Rd, Camperdown, NSW, 2050
Country 133767 0
Australia
Phone 133767 0
+61 2 9036 3136
Fax 133767 0
Email 133767 0
[email protected]
Contact person for scientific queries
Name 133768 0
Lauren Monds
Address 133768 0
Central Clinical School, Faculty of Medicine and Health, USYD; 92 Parramatta Rd, Camperdown, NSW, 2050
Country 133768 0
Australia
Phone 133768 0
+61 2 9036 3136
Fax 133768 0
Email 133768 0
[email protected]

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment


What supporting documents are/will be available?

Doc. No.TypeCitationLinkEmailOther DetailsAttachment
22209Study protocol https://osf.io/r2unh 
22211Statistical analysis plan https://osf.io/r2unh 



Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
No additional documents have been identified.