The Effects of Non-invasive Brain Stimulation on Treatment Adherence in Schizophrenia

March 25, 2025 updated by: Philip Gerretsen, Centre for Addiction and Mental Health

The Effects of Adjunctive Transcranial Direct Current Stimulation on Treatment Adherence in Schizophrenia

This study seeks to explore the effects of transcranial direct current stimulation (tDCS), a non-invasive method of brain stimulation, as an adjunctive treatment to improve antipsychotic medication adherence in patients with schizophrenia (SCZ). The investigators hypothesize that 20 sessions of tDCS will improve medication nonadherence in patients with SCZ.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

The proposed study will investigate the effects of adjunctive tDCS on antipsychotic medication adherence by targeting brain regions implicated in impaired insight, a primary contributor to medication nonadherence in patients with SCZ. Participants will be randomized to receive either active or sham tDCS. tDCS will be administered twice-daily for 10 days (20 sessions) excluding weekends. Brain scans will be performed before and after 10 days of tDCS. Antipsychotic drug adherence will be assessed based primarily on pill-count, and secondarily, plasma level concentrations and clinician-judgement.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
106

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • Canada
    • Ontario
      • Toronto, Ontario, Canada, M5T 1R8
        • Recruiting
        • Centre for Addiction and Mental Health
        • Contact:
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Male or female participants of any race or ethnicity
  2. Inpatients or outpatients ≥18 years of age
  3. DSM-V diagnosis of SCZ or schizoaffective disorder
  4. Capable of consenting to participate in the research study
  5. On a stable dose of antipsychotic drug and other concomitant medications for at least 2 months, and unlikely to undergo changes in dose during the study

Exclusion Criteria:

  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 and nicotine) 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 (eg., claustrophobia)
  8. Pregnancy

  9. Score < 32 on the Wide Range Achievement Test-III

    • Substance misuse: In addition to impaired insight, substance misuse is one of the principle contributors to medication nonadherence. To minimize the possibility of its influence, participants with a DSM-V diagnosis of substance dependence within 1 month of entering the study or a positive urine drug test (except for cannabis/marijuana) at the screening visit will be excluded. Substance use and urine drug screens will be assessed at subsequent study visits.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Active TDCS
In the active condition, a constant current of 2 mA intensity will be applied for 20 min to the parietal regions, using P3 as the cathode and P4 as the anode.
Other: Active TDCS
Participants will receive active TDCS stimulation.
Sham Comparator: Sham TDCS
In the sham condition, stimulation will be administered using the same parameters at the site of active treatment, but the current will be turned off after 30 seconds.
Other: Sham TDCS
Participants will receive sham TDCS stimulation.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Medication adherence - Pill Count
Time Frame: During 3-month follow up phase
Pill count or percentage of weekly antipsychotic medication adherence will be assessed during the 3-month follow up phase after TDCS is completed.
During 3-month follow up phase
Medication adherence - Plasma Monitoring
Time Frame: Blood concentration of antipsychotic medication will be measured on day of the first TDCS session before TDCS starts, after 1 week of TDCS is completed, after 2 weeks of TDCS are completed, and during the 3-month follow up phase.
Blood concentrations of antipsychotic medication will be measured at different points in the study to assess medication adherence.
Blood concentration of antipsychotic medication will be measured on day of the first TDCS session before TDCS starts, after 1 week of TDCS is completed, after 2 weeks of TDCS are completed, and during the 3-month follow up phase.
Medication adherence - Clinician Rating
Time Frame: During 3-month follow up phase
The Clinician Adherence Rating Scale is a 7-point clinician rated measure which takes into account patients' self-report, medication adherence, and changes in plasma concentrations to provide a comprehensive assessment of antipsychotic medication adherence. A higher score represents greater adherence.
During 3-month follow up phase

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Insight into Psychosis
Time Frame: Illness awareness will be assessed before the TDCS phase begins, after 2 weeks of TDCS are completed, and during the 3-month follow up period
Level of illness awareness will be assessed by the VAGUS Insight into Psychosis scale. The VAGUS assesses the core domains of insight into psychosis. VAGUS has both self-report and clinician-rated versions with good inter-scale reliability and test-retest reliability. Higher scores indicate better insight into illness.
Illness awareness will be assessed before the TDCS phase begins, after 2 weeks of TDCS are completed, and during the 3-month follow up period

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Centre for Addiction and Mental Health

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Philip Gerretsen, MD, PhD, Centre for Addiction and Mental Health

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
August 15, 2019

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
March 31, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
March 31, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
May 23, 2019

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 24, 2019

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
July 26, 2019

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
March 28, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 25, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
March 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 103-2018

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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