Examining brain changes in schizophrenia patients using tDCS

Does tDCS Change Synaptic Density in the Brains of Patients With Schizophrenia

Observational Centre for Addiction and Mental Health · NCT05435300

This study is testing if a brain stimulation treatment called tDCS can change brain connections in people with schizophrenia or schizoaffective disorder.

Quick facts

Study typeObservational
Enrollment20 (estimated)
Ages18 Years and up
SexAll
SponsorCentre for Addiction and Mental Health Academic / other
Drugs / interventionsradiation
Locations1 site (Toronto, Ontario)
Trial IDNCT05435300 on ClinicalTrials.gov

What this trial studies

This observational study aims to investigate the effects of transcranial direct current stimulation (tDCS) on synaptic density in patients diagnosed with schizophrenia or schizoaffective disorder. Utilizing a novel positron emission tomography (PET) radiotracer, [18F]SDM-8, the study will measure synaptic density levels before and after a two-week tDCS treatment period. Participants will be enrolled from a parent study focusing on treatment adherence, and clinical assessments will be conducted alongside PET scans to provide a comprehensive understanding of tDCS's impact on brain function.

Who should consider this trial

Good fit: Ideal candidates include adults aged 18 and older with a DSM-V diagnosis of schizophrenia or schizoaffective disorder who are stable on their medication.

Not a fit: Patients with unstable medical conditions, severe thought disorders, or those unable to consent may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could enhance our understanding of how tDCS affects brain structure and potentially improve treatment strategies for schizophrenia.

How similar studies have performed: While the use of tDCS in schizophrenia is being explored, this specific approach utilizing [18F]SDM-8 for measuring synaptic density is novel and has not been extensively tested in prior studies.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

Enrolment in the tDCS-adherence parent study (REB# 103-2018). The parent study inclusion criteria are:

1. Male or female participants of any race or ethnicity
2. Inpatients or outpatients ≥18 years of age
3. DSM-V diagnosis of schizophrenia or schizoaffective disorder
4. Capable of consenting to participate in the research study
5. 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.

Exclusion Criteria:

The exclusion criteria for this study will be the same as the parent study (REB 103-2018). The parent study exclusion criteria are:

1. Unwilling or incapable to consent to the study based on the MacArthur Test of Competence
2. Unstable medical or any concomitant major medical or neurological illness, including a history of seizures
3. Acute suicidal or homicidal ideation
4. Formal thought disorder rating ≥3 on the Positive and Negative Syndrome Scale (PANSS) P2 conceptual disorganization item
5. DSM-V substance dependence (except caffeine, nicotine, and cannabis/marijuana) within 1 month of entering the study
6. Positive urine drug screen except for cannabis/marijuana at the screening visit
7. Metal implants or pacemaker precluding an MRI scan or other contraindications to MRI (e.g., claustrophobia)
8. Pregnancy
9. Score \<32 on the Wide Range Achievement Test-III

Additional exclusion criteria for this companion study are:

1. Unwilling or incapable to consent to the study based on the MacArthur Test of Competence
2. Exposure to long-acting injectable antipsychotics in the last 6 months
3. Exceeding allowed annual radiation exposure levels (20 mSv), as outlined by our PET Centre guidelines
4. Receiving treatment with medications such as levetiracetam that blocks SV2a binding
5. Disorders of coagulation or taking anticoagulant medication
6. Having completed multiple PET scans in the past, such that participation in this study would cause participant to exceed lifetime limit (8 PET scans)

Where this trial is running

Toronto, Ontario

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions SchizophreniaSchizoaffectivePositron emission tomography
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.