Transcranial Brain Stimulation and Its Underlying Neural Mechanisms as a Novel Treatment for Auditory Hallucinations

May 18, 2026 updated by: Marco Hirnstein, University of Bergen
The present study aims to investigate whether transcranial direct current stimulation (tDCS) reduces auditory hallucinations in patients with psychosis. In addition, the neuronal changes of tDCS will be examined.

Study Overview

Status

Status

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

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 majority of patients with psychosis experience hallucinations, particularly auditory hallucinations are frequent. The hallucinations often leads to massive distress and impairments in social functioning and sometimes even order patients to commit acts of violence against themselves or others. The standard treatment for auditory hallucinations is antipsychotic medication. However, side-effects can be severe and about 25-30% of the patients do not respond to the medication. Transcranial direct current stimulation is a non-invasive brain stimulation technique, which modulates cortical excitability in a pain-free free with mild transient adverse effects, if any. Typically, cortical excitability underneath the anode is boosted while cathodal stimulation has inhibitory effects. Previous studies found that 2 daily sessions of 20 min tDCS for five subsequent days may reduce auditory hallucinations. Investigators want to further assess the efficacy of tDCS in sample that is large enough to detect medium to large effects. In addition, investigators want to investigate the neural mechanisms that underlie the tDCS treatment by examining various neuroimaging parameters before, immediately after treatment, and 3 months after treatment.

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 (Actual)

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.
24

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 Locations

  • Norway
    • Hordaland
      • Bergen, Hordaland, Norway, 5009
        • University of Bergen

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:

  • Diagnosed with schizophrenia spectrum disorder or other psychotic disorder
  • Frequent auditory hallucinations (at least 5 times a week).
  • Patients are on a stable dose of antipsychotic medication (which can also be zero) for at least 2 weeks.
  • Mentally competent for informed consent.
  • Provided informed consent.

Exclusion Criteria:

  • Metal objects in or around the head that cannot be removed (i.e. cochlear implant, surgical clips, piercing)
  • History of seizures, or a history of seizures in first-degree relatives.
  • History of eye trauma with a metal object or professional metal workers
  • History of brain surgery, brain infarction, head trauma, cerebrovascular accident, broken skull, brain tumour, heart disease, cardiac pacemaker.
  • Skin disease on the scalp on the position of the tDCS electrodes
  • Coercive treatment based on a judicial ruling
  • Pregnancy in female patients

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: Triple

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: real tDCS
DC Stimulator PLUS (NeuroConn) The real tDCS condition comprises two daily sessions of 20 min tDCS, separated by a minimum break of 3h, for five consecutive days. Anodal and cathodal tDCS will be applied with 2mA to the left dorsolateral prefrontal cortex (a point midway between F3 and FP1) and the left peri-Sylvian region (a point midway between T3 and P3), respectively. Electrode size is 7cm x 5cm.
Device: DC Stimulator PLUS (NeuroConn)
Sham Comparator: sham tDCS
DC Stimulator PLUS (NeuroConn) The sham condition is identical to the "real tDCS" condition except that after 40s of tDCS stimulation is going to be reduced to a small pulse every 550msec (110 μA over 15 msec) through the remainder of the 20 minute period.
Device: DC Stimulator PLUS (NeuroConn)

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
Auditory Hallucination Rating Scale (AHRS)
Time Frame: Change from Baseline to immediately after treatment and 3 months after treatment
Self-report measure for severity of hallucinations; consists of seven items; Sum can range from 2 to 41; higher values indicate more severe hallucinations
Change from Baseline to immediately after treatment and 3 months after treatment
Hallucination Change Scale (HCS)
Time Frame: Change from Baseline to immediately after treatment
Measure for changes in severity of auditory hallucinations; participants rated in percent how much their symptoms had improved (or worsened). The range is thus -100 (symptoms reduced by 100%) to +100 (symptoms worsened by 100%)
Change from Baseline to immediately after treatment

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
Positive and Negative Syndrome Scale (PANSS)
Time Frame: Change from Baseline to immediately after treatment and 3 months after treatment
Positive Sum Score; conducted by clinical rater; consists of 10 items, range 7-49; higher scores indicate more severe symptoms
Change from Baseline to immediately after treatment and 3 months after treatment
Stroop Task
Time Frame: Change from Baseline to immediately after treatment and 3 months after treatment
Measure of executive functioning, Stroop condition #3 in seconds; higher values indicate longer task duration and worse performance
Change from Baseline to immediately after treatment and 3 months after treatment
Trailmaking Test B
Time Frame: Change from Baseline to immediately after treatment and 3 months after treatment
Measure of visuomotor speed
Change from Baseline to immediately after treatment and 3 months after treatment
Apathy Evaluation Scale
Time Frame: Before, immediately after treatment, and at 3 month follow-up
Total sum of AES score; consists of 18 items; range 18-72, higher values indicate higher degree of apathy
Before, immediately after treatment, and at 3 month follow-up
The Clinical Global Impressions Scale - Severity
Time Frame: Change from Baseline to immediately after treatment and 3 months after treatment
Measure of global functioning; rated by clinician on a 7-point scale, with the severity of illness scale rated from 1 (normal) through to 7 (most severely ill)
Change from Baseline to immediately after treatment and 3 months after treatment
Global Assessment of Functioning - S
Time Frame: Change from Baseline to immediately after treatment and 3 months after treatment
Measure of global functioning - Symptoms, rated by clinician; measures how much a person's symptoms affect their day-to-day life on a scale of 0 to 100, where 0 is severely impacted in daily life by symptoms and 100 is not affected at all
Change from Baseline to immediately after treatment and 3 months after treatment
Dichotic Listening Paradigm
Time Frame: Change from Baseline to immediately after treatment and 3 months after treatment
Measure of executive functioning, forced left condition, percentage reported from left ear
Change from Baseline to immediately after treatment and 3 months after treatment
Dichotic Listening Laterality Index
Time Frame: Change from Baseline to immediately after treatment and 3 months after treatment
Measure of language lateralization, laterality index in non-forced condition, laterality index is computed according to formula: LI=[(R-L)/(R+L)]*100, where "L" and "R" are the number of correct left and right ear responses, respectively. values can range between -100 (only syllables from left ear correctly reported and +100 (only correct syllables from right ear reported)
Change from Baseline to immediately after treatment and 3 months after treatment

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.
University of Bergen

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Helse-Bergen HF

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: Marco Hirnstein, PhD, University of Bergen

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

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.
July 1, 2016

Primary Completion (Actual)

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 1, 2020

Study Completion (Actual)

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 1, 2020

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 6, 2016

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.
May 9, 2016

First Posted (Estimated)

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.
May 11, 2016

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.
May 19, 2026

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.
May 18, 2026

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.
May 1, 2026

More Information

Terms related to this study

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.
  • UiB-BFS-01/2016

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Data will be shared with the ERC Advanced Projects Advanced Grant #249516 "VOICE" and #693124 "ONOFF".

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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