SchizophreniaNCT05435300
Does tDCS Change Synaptic Density in the Brains of Patients With Schizophrenia
An observational study of Schizophrenia and Schizoaffective, run by Centre for Addiction and Mental Health at 1 site in Canada.
Trial summary
This study will examine changes in synaptic density with transcranial direct current stimulation (tDCS) in the brains of patients with schizophrenia. Synaptic density levels will be measured using a novel positron emission tomography (PET) radiotracer [18F]SDM-8, which is currently the best-in-class method to quantify… Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Schizophrenia, Schizoaffective
- What is being tested?
- PET Scan
- How many people
- 20 participants
- Where
- 1 siteCanada
- Study dates
- 17 Sep 2021to Sep 2026
- Phase
- Observational
- 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 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Participants will have Schizophrenia/Schizoaffective Disorder and currently enrolled in the tDCS-adherence parent study (REB# 103-2018).
Who may be able to join
- Enrolment in the tDCS-adherence parent study (REB# 103-2018). The parent study inclusion criteria are:
- Male or female participants of any race or ethnicity
- Inpatients or outpatients ≥18 years of age
- DSM-V diagnosis of schizophrenia or schizoaffective disorder
- Capable of consenting to participate in the research study
- On a stable dose of oral antipsychotic drug and other concomitant medications for at least 2 months, and unlikely to undergo changes in dose during the study.
Who cannot join
- The exclusion criteria for this study will be the same as the parent study (REB 103-2018). The parent study exclusion criteria are:
- Unwilling or incapable to consent to the study based on the MacArthur Test of Competence
- Unstable medical or any concomitant major medical or neurological illness, including a history of seizures
- Acute suicidal or homicidal ideation
- Formal thought disorder rating ≥3 on the Positive and Negative Syndrome Scale (PANSS) P2 conceptual disorganization item
- DSM-V substance dependence (except caffeine, nicotine, and cannabis/marijuana) within 1 month of entering the study
Show all 17Show fewer
- Positive urine drug screen except for cannabis/marijuana at the screening visit
- Metal implants or pacemaker precluding an MRI scan or other contraindications to MRI (e.g., claustrophobia)
- Pregnancy
- Score <32 on the Wide Range Achievement Test-III
- Additional exclusion criteria for this companion study are:
- Unwilling or incapable to consent to the study based on the MacArthur Test of Competence
- Exposure to long-acting injectable antipsychotics in the last 6 months
- Exceeding allowed annual radiation exposure levels (20 mSv), as outlined by our PET Centre guidelines
- Receiving treatment with medications such as levetiracetam that blocks SV2a binding
- Disorders of coagulation or taking anticoagulant medication
- Having completed multiple PET scans in the past, such that participation in this study would cause participant to exceed lifetime limit (8 PET scans)
Trial locations and contacts
1 site in 1 country.
About this study
This study will examine changes in synaptic density with transcranial direct current stimulation (tDCS) in the brains of patients with schizophrenia. Synaptic density levels will be measured using a novel positron emission tomography (PET) radiotracer [18F]SDM-8, which is currently the best-in-class method to quantify synaptic density in humans. This will be a companion study to a parent study by our group examining the effects of tDCS on treatment adherence in schizophrenia (REB #103-2018).
Read the detailed description
The aim of our study is to examine if tDCS induces synaptic density changes in patients with schizophrenia using [18F]SDM-8. Our study will help elucidate the mechanism through which tDCS affects the brain.
PET scans will be offered to participants that meet the inclusion and exclusion criteria at the initial screening visit. Participants will be scanned with the novel PET tracer [18F]SDM-8 to quantify synaptic density levels. PET scans will be timed to coincide to the two time-points, before and after 2-weeks of tDCS treatment that is completed under the parent study protocol (REB #103-2018). Clinical assessments will be done at the same time.
- Conditions
- Schizophrenia, Schizoaffective
- Being tested
- PET Scan
- Keywords
- Positron emission tomography
- Medical subject headings
- Schizophrenia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PET ScanOther
Participants will undergo two PET scans throughout the study.
| Study group | Role | What they receive |
|---|---|---|
| Schizophrenia/Schizoaffective Disorder | Participants with Schizophrenia/Schizoaffective Disorder and currently enrolled in the tDCS-adherence parent study (REB# 103-2018). Receives: Other: PET Scan |
What is being measured
The primary outcome is the main question the study is designed to answer.
Synaptic density changes
The primary outcome measure is the [18F]SDM-8 standard uptake value (SUV) and distribution volume ratio (DVR) in cortical and subcortical gray matter regions, measured by PET Scans
Measured: PET scans will be timed to coincide to the two time-points, before and after 2-weeks of tDCS treatment that is completed under the parent study protocol (REB #103-2018)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 Jun 2022
- Study start17 Sep 2021
- Primary completionSep 2026 (estimated)
- Study completionSep 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for SchizophreniaStudies of the same condition, open and under way.
- More trials run by Centre for Addiction and Mental HealthThe sponsor's other registered studies.
- 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
- Observational
- Observational model
- Case only
- Time perspective
- Prospective
- Enrolment
- 20 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Centre for Addiction and Mental Health
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Philip Gerretsen, MD, PhD, Principal investigator, Centre for Addiction and Mental Health
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05435300
- Sponsor's protocol ID
- 118/2020
- Status last verified
- Aug 2026
- First submitted
- 23 Jun 2022
- Last updated
- 27 Aug 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 27 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Does tDCS Change Synaptic Density in the Brains of Patients With Schizophrenia
- ClinicalTrials.gov ID
- NCT05435300
- Acronym / sponsor ID
- 118/2020
- Conditions
- Schizophrenia, Schizoaffective
- Keywords
- Positron emission tomography
- Study type
- Observational
- Recruitment status
- Active, not recruiting
- Enrolment
- 20 participants (estimated)
- Lead sponsor
- Centre for Addiction and Mental HealthUniversity, hospital or other
- Study start
- 17 Sep 2021 (actual)
- Primary completion
- Sep 2026 (estimated)
- Study completion
- Sep 2026 (estimated)
- First posted
- 28 Jun 2022 (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 study will examine changes in synaptic density with transcranial direct current stimulation (tDCS) in the brains of patients with schizophrenia. Synaptic density levels will be measured using a novel positron emission tomography (PET) radiotracer [18F]SDM-8, which is currently the best-in-class method to quantify synaptic density in humans. This will be a companion study to a parent study by our group examining the effects of tDCS on treatment adherence in schizophrenia (REB #103-2018).
Detailed description
The aim of our study is to examine if tDCS induces synaptic density changes in patients with schizophrenia using [18F]SDM-8. Our study will help elucidate the mechanism through which tDCS affects the brain.
PET scans will be offered to participants that meet the inclusion and exclusion criteria at the initial screening visit. Participants will be scanned with the novel PET tracer [18F]SDM-8 to quantify synaptic density levels. PET scans will be timed to coincide to the two time-points, before and after 2-weeks of tDCS treatment that is completed under the parent study protocol (REB #103-2018). Clinical assessments will be done at the same time.
Study design
- Observational model
- Case only
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Schizophrenia/Schizoaffective Disorder | – | Other: PET ScanParticipants with Schizophrenia/Schizoaffective Disorder and currently enrolled in the tDCS-adherence parent study (REB# 103-2018). |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Participants will have Schizophrenia/Schizoaffective Disorder and currently enrolled in the tDCS-adherence parent study (REB# 103-2018).
Key inclusion criteria (6 listed)
- Enrolment in the tDCS-adherence parent study (REB# 103-2018). The parent study inclusion criteria are:
- Male or female participants of any race or ethnicity
- Inpatients or outpatients ≥18 years of age
- DSM-V diagnosis of schizophrenia or schizoaffective disorder
- Capable of consenting to participate in the research study
Key exclusion criteria (17 listed)
- The exclusion criteria for this study will be the same as the parent study (REB 103-2018). The parent study exclusion criteria are:
- Unwilling or incapable to consent to the study based on the MacArthur Test of Competence
- Unstable medical or any concomitant major medical or neurological illness, including a history of seizures
- Acute suicidal or homicidal ideation
- Formal thought disorder rating ≥3 on the Positive and Negative Syndrome Scale (PANSS) P2 conceptual disorganization item
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 |
|---|---|---|
| PET ScanParticipants will undergo two PET scans throughout the study. | Other | Schizophrenia/Schizoaffective Disorder |
Primary outcome
Synaptic density changes
Time frame: PET scans will be timed to coincide to the two time-points, before and after 2-weeks of tDCS treatment that is completed under the parent study protocol (REB #103-2018)
The primary outcome measure is the [18F]SDM-8 standard uptake value (SUV) and distribution volume ratio (DVR) in cortical and subcortical gray matter regions, measured by PET Scans
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 27 Aug 2026.
- The Centre for Addiction and Mental Health (CAMH) is the leading mental health and addictions research facility in Canada, and one of the largest in the world.Link provided by the sponsor.
- Individual participant dataSharing planned: No
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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. This study is not recruiting at the moment.
Philip Gerretsen, MD, PhD principal investigator
Centre for Addiction and Mental Health
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Schizophrenia and Schizoaffective, run by Centre for Addiction and Mental Health at 1 site in Canada.
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 6 inclusion and 17 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: under way, not looking for participants, as of the sponsor's last update on 27 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 Canada. 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.
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?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Synaptic density changes (time frame: PET scans will be timed to coincide to the two time-points, before and after 2-weeks of tDCS treatment that is completed under the parent study protocol (REB #103-2018)). 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 27 Aug 2026.