InsomniaPhase 2LOCUSleepNCT07392177
Understanding the Role of the Locus Coeruleus in Insomnia
A Phase 2 study testing Dexmedetomidine in people with Insomnia, run by Woolcock Institute of Medical Research at 1 site in Australia.
Trial summary
This research project aims to better understand the neurobiological mechanistic underpinnings of insomnia disorder. The main question is whether cortical hyperarousal in individuals with insomnia disorder, measured by electroencephalograhic (EEG) infraslow oscillation coupling of sigma power during non-rapid eye… Read more about this study
- Who is it for?
- Ages 30 to 65 years
- Conditions the study is for
- Insomnia
- What is being tested?
- Dexmedetomidine
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 15 participants
- Where
- 1 siteAustralia
- Study dates
- 12 Aug 2026to Mar 2027
- Phase
- Phase 2
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 30 to 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Diagnosis of insomnia disorder (DSM-5-TR)
- Insomnia severity index (ISI) score ≥15
- Able to provide informed consent
- Fluent English literacy
Who cannot join
- Medically diagnosis of sleep disordered breathing (i.e. sleep apnea) or sleep or circadian disorder other than insomnia
- Uncontrolled psychiatric disorders
- High dependence on medical care
- History of, or current suicide ideation (Patient Health Questionnaire (PHQ-9) questionnaire)
- Pregnancy or actively trying to conceive, or lactating
- Shiftwork - defined as work outside of business hours (before 8am or after 6pm) conducted at least once per week
Show all 11Show fewer
- Travel across time zones of over 2 h time difference in the past week
- Contraindicate the patient's participation in the clinical trial due to safety concerns or compliance with clinical study procedures
- Concomitant use of medicines that are inhibitors, or moderate to strong inducers, of CYP3A4; regular use of hypnotics and other medications that can cause additive sedation or psychostimulants or non-amphetamine psychostimulants within 14 days of starting the clinical trial
- Ongoing use of THC- or CBD-containing products; dependence or any other drug or alcohol dependence
- Allergy to lactose
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Camilla Hoyos, PhD contact
Australia1 site, 1 recruiting
- Recruiting
Woolcock Institute of Medical Research
Macquarie Park, New South Wales, 2113
Greg Kaplan, PhD, +61 2 9805 3232, grigori.kaplan@woolcock.org.au
Christopher Gordon, PhD
About this study
Official title: An Alpha2-adrenoceptor Agonist to Reduce Locus Coeruleus Activity During Sleep in Adults With Insomnia Disorder: a Pilot Randomised Placebo-controlled Cross-over Study
This research project aims to better understand the neurobiological mechanistic underpinnings of insomnia disorder. The main question is whether cortical hyperarousal in individuals with insomnia disorder, measured by electroencephalograhic (EEG) infraslow oscillation coupling of sigma power during non-rapid eye movement (NREM) sleep and theta power during rapid eye movement (REM) sleep, is related to locus coeruleus activity.
Read the detailed description
This trial is a double-blinded, placebo-controlled, randomised controlled cross over trial of dexmedetomidine or placebo in adults with insomnia disorder. Participants will be recruited using social media, bulletin boards and patient referrals from the Woolcock Institute of Medical Research clinics. Participants will be asked to complete an online pre-screening webpage (RedCap) to check for eligibility, and provided with the Participant Information Sheet (PIS) and asked for contact details for an in-person screening visit. The participants will have the study explained in detail during the screening visit followed by written informed consent. The participant will then undergo a medical screening for diagnosis of insomnia disorder and the medical officer will sign the consent form. Thereafter, the participant will complete baseline questionnaires and be randomised to either dexmedetomidine or placebo for the 2 sleep laboratory visits. Participants will then be instructed to maintain their regular sleep-wake patterns for seven days before the first sleep laboratory visit (Visit 1). During Visit 1, participants will undergo a number of assessments (pre-sleep locus coeruleus activity measured using pupillometry, electroencephalography (EEG), functional near-infrared spectroscopy (fNIRS) before and during sleep and questionnaires about subjective hyperarousal. Participants will receive either dexmedetomidine or placebo. Following Visit 1, participants will have a 14-day washout, before Visit 2, which will repeat the procedures of Visit 1, but participants will receive the alternate condition (placebo or dexmedetomidine). The study will be coordinated from the Woolcock Institute of Medical Research, Sydney, Macquarie University, NSW, 2113, Australia.
- Conditions
- Insomnia
- Being tested
- Dexmedetomidine, Placebo
- Keywords
- Electroencephalography, Sleep, Locus coeruleus, Hyperarousal
- Medical subject headings
- Sleep Initiation and Maintenance Disorders
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
DexmedetomidineDrug
A buccal tablet containing 96 µg dexmedetomidine will be taken before habitual bedtime.
PlaceboDrug
Placebo tablets will contain identical excipient without the active ingredient (dexmedetomidine) and manufactured under the same condition as the active. Placebo tablets, packs and instructions will be identical in every respect to enable the double-blind study design.
| Study group | Role | What they receive |
|---|---|---|
| Dexmedetomidine | Experimental | A 96 µg dexmedetomidine tablet taken during the sleep laboratory visit only Receives: Drug: Dexmedetomidine |
| Placebo | Active comparator | Matching placebo tablet taken during the sleep laboratory visit only Receives: Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Electrographic (EEG) signatures
Electrographic (EEG) infraslow oscillations (~50 sec) of sigma power and sleep spindle coupling during non-rapid eye movement (NREM) sleep and theta power during rapid eye movement (REM) sleep.
Measured: Baseline and 14 days
Secondary outcomes (7)
Sleep Fragmentation
Polysomnography (PSG) measure conducted during the intervention and control (wake after sleep onset)
Measured: Baseline and 14 days
EEG power
Electroencephalographic (EEG) power during non-rapid eye movement (NREM) (stages 2 and 3) and rapid eye movement (REM) sleep. Unit of measurement is μV^2.
Measured: Baseline and 14 days
Neurovascular activity (fNIRS)
Measurement of global blood flow using functional near-infrared spectroscopy (fNIRS).
Measured: Baseline and 14 days
Cardiopulmonary Coupling (CPC)
Cardiopulmonary coupling provides a global measure of autonomic function
Measured: Baseline and 14 days
Pupillometry
Pupil sizes will be assessed as a surrogate of locus coeruleus activity
Measured: Baseline and 14 days
Subjective hyperarousal
Pre-Sleep Arousal Scale (PSAS) before sleep. Scored by summing 16 items (rated 1 (not at all) to 5 (extremely)) with a total score between 16 to 80
Measured: Baseline and 14 days
Subjective sleep quality
Self-reported rating of sleep quality (0-9) with higher scores indicating worse sleep. This will assessed in the morning after the overnight sleep study.
Measured: Baseline and 14 days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted6 Feb 2026
- Study start12 Aug 2026
- Primary completionMar 2027 (estimated)
- Study completionMar 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for InsomniaStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- Double-blind, randomised, placebo-controlled crossover study
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 15 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Woolcock Institute of Medical Research
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Christopher Gordon, Woolcock Institute of Medical Research
- Investigators
- Christopher Gordon, PhD, Principal investigator, Woolcock Institute of Medical ResearchBrendon Yee, MBChB, PhD, Principal investigator, Woolcock Institute of Medical Research
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07392177
- Sponsor's protocol ID
- 19522
- Acronym
- LOCUSleep
- Status last verified
- Aug 2026
- First submitted
- 8 Dec 2025
- Last updated
- 19 Aug 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: Non-identifiable IPD will be shared upon reasonable request to the Principal Investigators.
Study at a glance
From the registry record, last updated by the sponsor on 19 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- An Alpha2-adrenoceptor Agonist to Reduce Locus Coeruleus Activity During Sleep in Adults With Insomnia Disorder: a Pilot Randomised Placebo-controlled Cross-over Study
- ClinicalTrials.gov ID
- NCT07392177
- Acronym / sponsor ID
- LOCUSleep / 19522
- Conditions
- Insomnia
- Keywords
- Electroencephalography, Sleep, Locus coeruleus, Hyperarousal
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 15 participants (estimated)
- Lead sponsor
- Woolcock Institute of Medical ResearchUniversity, hospital or other
- Study start
- 12 Aug 2026 (actual)
- Primary completion
- Mar 2027 (estimated)
- Study completion
- Mar 2027 (estimated)
- First posted
- 6 Feb 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This research project aims to better understand the neurobiological mechanistic underpinnings of insomnia disorder. The main question is whether cortical hyperarousal in individuals with insomnia disorder, measured by electroencephalograhic (EEG) infraslow oscillation coupling of sigma power during non-rapid eye movement (NREM) sleep and theta power during rapid eye movement (REM) sleep, is related to locus coeruleus activity.
Detailed description
This trial is a double-blinded, placebo-controlled, randomised controlled cross over trial of dexmedetomidine or placebo in adults with insomnia disorder. Participants will be recruited using social media, bulletin boards and patient referrals from the Woolcock Institute of Medical Research clinics. Participants will be asked to complete an online pre-screening webpage (RedCap) to check for eligibility, and provided with the Participant Information Sheet (PIS) and asked for contact details for an in-person screening visit. The participants will have the study explained in detail during the screening visit followed by written informed consent. The participant will then undergo a medical screening for diagnosis of insomnia disorder and the medical officer will sign the consent form. Thereafter, the participant will complete baseline questionnaires and be randomised to either dexmedetomidine or placebo for the 2 sleep laboratory visits. Participants will then be instructed to maintain their regular sleep-wake patterns for seven days before the first sleep laboratory visit (Visit 1). During Visit 1, participants will undergo a number of assessments (pre-sleep locus coeruleus activity measured using pupillometry, electroencephalography (EEG), functional near-infrared spectroscopy (fNIRS) before and during sleep and questionnaires about subjective hyperarousal. Participants will receive either dexmedetomidine or placebo. Following Visit 1, participants will have a 14-day washout, before Visit 2, which will repeat the procedures of Visit 1, but participants will receive the alternate condition (placebo or dexmedetomidine). The study will be coordinated from the Woolcock Institute of Medical Research, Sydney, Macquarie University, NSW, 2113, Australia.
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
- Model description
- Double-blind, randomised, placebo-controlled crossover study
| Arm | Type | Receives |
|---|---|---|
| Dexmedetomidine | Experimental | Drug: DexmedetomidineA 96 µg dexmedetomidine tablet taken during the sleep laboratory visit only |
| Placebo | Active comparator | Drug: PlaceboMatching placebo tablet taken during the sleep laboratory visit only |
Who may qualify
- Ages
- 30 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Diagnosis of insomnia disorder (DSM-5-TR)
- Insomnia severity index (ISI) score ≥15
- Able to provide informed consent
- Fluent English literacy
Key exclusion criteria (11 listed)
- Medically diagnosis of sleep disordered breathing (i.e. sleep apnea) or sleep or circadian disorder other than insomnia
- Uncontrolled psychiatric disorders
- High dependence on medical care
- History of, or current suicide ideation (Patient Health Questionnaire (PHQ-9) questionnaire)
- Pregnancy or actively trying to conceive, or lactating
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| DexmedetomidineA buccal tablet containing 96 µg dexmedetomidine will be taken before habitual bedtime. | Drug | Dexmedetomidine |
| PlaceboPlacebo tablets will contain identical excipient without the active ingredient (dexmedetomidine) and manufactured under the same condition as the active. Placebo tablets, packs and instructions will be identical in every respect to enable the double-blind study design. | Drug | Placebo |
Primary outcome
Electrographic (EEG) signatures
Time frame: Baseline and 14 days
Electrographic (EEG) infraslow oscillations (~50 sec) of sigma power and sleep spindle coupling during non-rapid eye movement (NREM) sleep and theta power during rapid eye movement (REM) sleep.
7 secondary outcomes
Sleep Fragmentation
Time frame: Baseline and 14 days
EEG power
Time frame: Baseline and 14 days
Neurovascular activity (fNIRS)
Time frame: Baseline and 14 days
Cardiopulmonary Coupling (CPC)
Time frame: Baseline and 14 days
Pupillometry
Time frame: Baseline and 14 days
Subjective hyperarousal
Time frame: Baseline and 14 days
Subjective sleep quality
Time frame: Baseline and 14 days
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 19 Aug 2026.
- Individual participant dataSharing planned: Yes. Non-identifiable IPD will be shared upon reasonable request to the Principal Investigators.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Camilla Hoyos, PhD contact
Christopher Gordon, PhD principal investigator
Woolcock Institute of Medical Research
Brendon Yee, MBChB, PhD principal investigator
Woolcock Institute of Medical Research
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing Dexmedetomidine in people with Insomnia, run by Woolcock Institute of Medical Research at 1 site in Australia.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 11 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 19 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Australia. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Christopher Gordon, PhD (+61 2 9805 3096, c.gordon@mq.edu.au), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Electrographic (EEG) signatures (time frame: Baseline and 14 days). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 19 Aug 2026.