Differences by Sex and Genotype in the Effects of Stress on Executive Functions

NCT ID: NCT04273880

Last Updated: 2024-05-08

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

RECRUITING

Clinical Phase

PHASE1

Total Enrollment

146 participants

Study Classification

INTERVENTIONAL

Study Start Date

2018-04-28

Study Completion Date

2024-12-31

Brief Summary

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The aim of this project is to test the effects of an environmental factor (mild stress) on prefrontal cortex (PFC) and the cognitive functions that depend on PFC (collectively called executive functions \[EFs\]), and to test our predictions concerning how those effects differ by biological factors (hormones and genotype). To test our hypotheses concerning mechanism, the investigators will model the effects of mild stress on EFs pharmacologically. The purpose is to pharmacologically model the effects of mild stress on the cognitive functions (collectively called "executive functions" \[EFs\]) dependent on the frontal lobe. The investigators would also like to investigate how gender differences and genotype mediate the effect of methylphenidate (MPH) on EFs.

Detailed Description

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The investigators propose to test each young adult twice; once on the lowest clinically relevant dose of MPH and once on a placebo (Vitamin C), with the order counterbalanced. The two testing sessions will be scheduled 4 weeks apart, once 90 minutes after taking 10mg MPH and once 90 minutes after taking a placebo (90 mg of Vitamin C). Peak plasma concentration of MPH is reached approximately 2 h after ingestion, thus to gain the maximum effect of MPH, the investigators will test subjects 90 minutes after ingestion. They will tell subjects that they are studying the effects of low-dose MPH on EFs, and that they expect it to help the EFs of some but hinder those of others, without telling them the study's predictions. Before each testing session, subjects will come to the lab 90 minutes in advance of the testing period. First, they will be given a pill they will take in front of a research assistant (MPH or placebo). The conditions will be counterbalanced across subjects within each subject group. This is a double-blind design, where neither subject nor tester will know which condition they will be in. The pills (10mg MPH, and 90mg Vitamin C) are made to be identical. They will be over-encapsulated with an opaque coloured capsule. The pills will be in kept in sealed containers that are labeled in such a way that neither the subjects, nor the testers, nor the PI, will not know which pill is which, until it is time for the data analysis. Only a pharmacist, at the compounding pharmacy, will know which container contains which pill.

At low doses the mode of action of MPH increases DA efflux specifically in PFC and preferentially enhances signal processing in PFC. Low dosages of MPH are often effective in improving EFs and specifically because of their effect on PFC. This slight increase of DA in the PFC is similar to the effects of mild stress on the brain, which is why the study uses a low dose of MPH as the pharmacological model of mild stress. Even mild stress markedly increases DA levels in PFC, impairing PFC function and EFs. The use of MPH is meant to mimic the effect of mild stress on the PFC and executive functions.

Purpose/objective: This double-blind study aims to compare performance on tasks of executive function between males, females when their estrogen levels are high, and females when their estrogen levels are low when they have undergone a pharmacological model of mild stress (low dosage of MPH) and when they have not undergone this stress. It also aims to compare the same across the three variants of the catechol-O-methyltransferase (COMT) genotype (methionine-methionine, methionine-valine, and valine-valine).

Hypotheses: MPH, like mild-stress, should raise PFC DA levels in COMT-Vals to optimal, but raise PFC DA levels in COMT-Mets past optimal (since low dose of MPH increases DA levels in PFC). While COMT-Mets generally show better EFs than COMT-Vals without MPH, on MPH that should be reversed with COMT-Vals performing better. An increase in PFC DA levels pharmacologically should mimic the sex difference in the effect of mild stress on EFs, harming females with high estrogen level's performance while enhancing males' performance on tasks of executive functions.

Conditions

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Stress

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

CROSSOVER

Primary Study Purpose

BASIC_SCIENCE

Blinding Strategy

TRIPLE

Participants Investigators Outcome Assessors
Double-blind.

Study Groups

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10 mg Psychostimulant

Drug: Methylphenidate (MPH) Participants will be tested twice, approximately one month apart. In one of the sessions, they will be given 10mg of MPH an hour and a half before the testing session is set to begin, to account for the time taken for the effects of the drug to start.

Group Type EXPERIMENTAL

Methylphenidate

Intervention Type DRUG

10mg of MPH taken an hour and a half before one of the testing sessions.

90 mg Vitamin C

Placebo: Vitamin C Participants will be tested twice, approximately one month apart. In one of the sessions, they will be given 90mg of Vitamin an hour and a half before the testing session is set to begin, to follow the exact protocol that is used for MPH.

Group Type PLACEBO_COMPARATOR

Vitamin C

Intervention Type DRUG

90 mg of Vitamin C taken an hour and a half before the other testing session

Interventions

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Methylphenidate

10mg of MPH taken an hour and a half before one of the testing sessions.

Intervention Type DRUG

Vitamin C

90 mg of Vitamin C taken an hour and a half before the other testing session

Intervention Type DRUG

Other Intervention Names

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02249324 Ascorbic Acid

Eligibility Criteria

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Inclusion Criteria

Between the ages of 20 and 35 years old

Exclusion Criteria

* a neurological impairment or disorder, learning disability, or psychological syndrome that might affect EF performance (such as ADHD)
* inability to understand the task instructions (which are in English), or difficulty hearing the instructions, seeing the stimuli, or executing a manual response.
* a serious adverse event during pregnancy or birth.
* an injury (such as a head injury with loss of consciousness) that might affect EF performance.
* a major trauma that might affect current EFs and stress responsivity
* undue current life stress level
* taking any medication that affects thinking, memory, mental clarity, or any other EF ability.
* taking any medication that influences circulating gonadal hormone levels (such as oral contraceptives \[birth control pill\]).
* having taken such medications within the preceding four months.
* smokers
* use of recreational drugs or consumption of alcohol 24 hours prior to the testing sessions
* women without a period that occurs roughly every month (predicting the onset of the next menses in women who don't have their period monthly is difficult)
* women who are pregnant or who are nursing.
* having the eye problem glaucoma
* having a heart condition
* being anxious, tense or agitated
* taking or have taken within the past 14 days an anti-depression medicine called a monoamine oxidase inhibitor or MAOI.
* taking pressor agents (for hypotension treatment)
* taking coumarin anticoagulants
* taking anticonvulsants (phenobarbital, diphenylhydantoin, primidone)
* taking phenylbutazone (nonsteroidal anti-inflammatory drug)
* taking tricyclic antidepressants (imipramine, desipramine)
* taking cold or allergy medicine that contain decongestants
* being allergic to anything in either the MPH or Vitamin C capsules (methylphenidate HCL, ascorbic acid, lactose, gelatin, Titanium dioxide, D\&C Red #28, FD\&C Blue #1, FD\&C Red #40)
Minimum Eligible Age

20 Years

Maximum Eligible Age

35 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

Yes

Sponsors

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National Institute on Drug Abuse (NIDA)

NIH

Sponsor Role collaborator

University of British Columbia

OTHER

Sponsor Role lead

Responsible Party

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Adele Diamond

Professor and Tier 1 Canada Research Chair

Responsibility Role PRINCIPAL_INVESTIGATOR

Principal Investigators

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Adele Diamond, PhD

Role: PRINCIPAL_INVESTIGATOR

University of British Columbia

Locations

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Developmental Cognitive Neuroscience Lab, Department of Psychiatry, University of British Columbia

Vancouver, British Columbia, Canada

Site Status RECRUITING

Countries

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Canada

Central Contacts

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Daphne Ling, BSc

Role: CONTACT

6048273074

David Abbott, BSc

Role: CONTACT

6048273074

Facility Contacts

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Daphne Ling, B.Sc. (Hon)

Role: primary

604-827-3074

David Abbott, B.Sc. (Hon)

Role: backup

604-827-3074

References

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Arnsten AF, Goldman-Rakic PS. Noise stress impairs prefrontal cortical cognitive function in monkeys: evidence for a hyperdopaminergic mechanism. Arch Gen Psychiatry. 1998 Apr;55(4):362-8. doi: 10.1001/archpsyc.55.4.362.

Reference Type BACKGROUND
PMID: 9554432 (View on PubMed)

Barkley, R. A. (2001). The inattentive type of ADHD as a distinct disorder: What remains to be done. Clinical Psychology: Science and Practice, 8, 489-493.

Reference Type BACKGROUND

Barkley RA, DuPaul GJ, McMurray MB. Attention deficit disorder with and without hyperactivity: clinical response to three dose levels of methylphenidate. Pediatrics. 1991 Apr;87(4):519-31.

Reference Type BACKGROUND
PMID: 2011430 (View on PubMed)

Berridge CW, Devilbiss DM, Andrzejewski ME, Arnsten AF, Kelley AE, Schmeichel B, Hamilton C, Spencer RC. Methylphenidate preferentially increases catecholamine neurotransmission within the prefrontal cortex at low doses that enhance cognitive function. Biol Psychiatry. 2006 Nov 15;60(10):1111-20. doi: 10.1016/j.biopsych.2006.04.022. Epub 2006 Jun 23.

Reference Type BACKGROUND
PMID: 16806100 (View on PubMed)

Cerqueira JJ, Mailliet F, Almeida OF, Jay TM, Sousa N. The prefrontal cortex as a key target of the maladaptive response to stress. J Neurosci. 2007 Mar 14;27(11):2781-7. doi: 10.1523/JNEUROSCI.4372-06.2007.

Reference Type BACKGROUND
PMID: 17360899 (View on PubMed)

Devilbiss DM, Berridge CW. Cognition-enhancing doses of methylphenidate preferentially increase prefrontal cortex neuronal responsiveness. Biol Psychiatry. 2008 Oct 1;64(7):626-35. doi: 10.1016/j.biopsych.2008.04.037. Epub 2008 Jun 30.

Reference Type BACKGROUND
PMID: 18585681 (View on PubMed)

Dickerson SS, Kemeny ME. Acute stressors and cortisol responses: a theoretical integration and synthesis of laboratory research. Psychol Bull. 2004 May;130(3):355-91. doi: 10.1037/0033-2909.130.3.355.

Reference Type BACKGROUND
PMID: 15122924 (View on PubMed)

Elliott R, Sahakian BJ, Matthews K, Bannerjea A, Rimmer J, Robbins TW. Effects of methylphenidate on spatial working memory and planning in healthy young adults. Psychopharmacology (Berl). 1997 May;131(2):196-206. doi: 10.1007/s002130050284.

Reference Type BACKGROUND
PMID: 9201809 (View on PubMed)

Lataster J, Collip D, Ceccarini J, Haas D, Booij L, van Os J, Pruessner J, Van Laere K, Myin-Germeys I. Psychosocial stress is associated with in vivo dopamine release in human ventromedial prefrontal cortex: a positron emission tomography study using [(1)(8)F]fallypride. Neuroimage. 2011 Oct 15;58(4):1081-9. doi: 10.1016/j.neuroimage.2011.07.030. Epub 2011 Jul 23.

Reference Type BACKGROUND
PMID: 21801840 (View on PubMed)

Milich, R., Balentine, A. C., & Lynam, D. R. (2001). ADHD combined type and ADHD predominantly inattentive type are distinct and unrelated disorders. Clinical Psychology: Science and Practice, 8, 463-488.

Reference Type BACKGROUND

Morrow BA, Roth RH, Elsworth JD. TMT, a predator odor, elevates mesoprefrontal dopamine metabolic activity and disrupts short-term working memory in the rat. Brain Res Bull. 2000 Aug;52(6):519-23. doi: 10.1016/s0361-9230(00)00290-2.

Reference Type BACKGROUND
PMID: 10974491 (View on PubMed)

Roth RH, Tam SY, Ida Y, Yang JX, Deutch AY. Stress and the mesocorticolimbic dopamine systems. Ann N Y Acad Sci. 1988;537:138-47. doi: 10.1111/j.1749-6632.1988.tb42102.x. No abstract available.

Reference Type BACKGROUND
PMID: 3059920 (View on PubMed)

Schmeichel BE, Zemlan FP, Berridge CW. A selective dopamine reuptake inhibitor improves prefrontal cortex-dependent cognitive function: potential relevance to attention deficit hyperactivity disorder. Neuropharmacology. 2013 Jan;64(1):321-8. doi: 10.1016/j.neuropharm.2012.07.005. Epub 2012 Jul 11.

Reference Type BACKGROUND
PMID: 22796428 (View on PubMed)

Spencer RC, Klein RM, Berridge CW. Psychostimulants act within the prefrontal cortex to improve cognitive function. Biol Psychiatry. 2012 Aug 1;72(3):221-7. doi: 10.1016/j.biopsych.2011.12.002. Epub 2011 Dec 29.

Reference Type BACKGROUND
PMID: 22209638 (View on PubMed)

Weiss M, Worling D, Wasdell M. A chart review study of the inattentive and combined types of ADHD. J Atten Disord. 2003 Sep;7(1):1-9. doi: 10.1177/108705470300700101.

Reference Type BACKGROUND
PMID: 14738177 (View on PubMed)

Other Identifiers

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5R01DA037285-05

Identifier Type: NIH

Identifier Source: secondary_id

View Link

H13-00286

Identifier Type: -

Identifier Source: org_study_id

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