Effects of Transcranial Direct Current Stimulation (tDCS) on Persistent Auditory Verbal Hallucinations in Schizophrenia

University of Ottawa

Status: Unknown

Conditions: Auditory Hallucination, Verbal

Treatments: Device: Transcranial direct current stimulation (tDCS)

Study type: Interventional

Funder types: Other

Identifiers

NCT04222582

2017020

Details and patient eligibility

About

Many individuals with schizophrenia struggle with auditory verbal hallucinations (AVHs). In some cases, these AVHs can be resistant to medication treatment. Previous research has found that transcranial direct current stimulation (tDCS) can be helpful in treating symptoms in individuals with other psychiatric disorders, such as depression. This study will assess if tDCS is effective in treating AVHs in individuals with schizophrenia. tDCS is a non-invasive form of brain stimulation which uses a weak current to temporarily excite or inhibit underlying cortical regions with small electrodes placed on the scalp. tDCS has been found to improve mental processes, including attention and memory function. In addition to examining the effect of tDCS on AVHs, this study will assess the effects of tDCS on mood as well as brain electrical activity with electroencephalogram (EEG) recordings. As an additional component, participants will be invited to participate in neuroimaging. Using magnetic resonance imaging (MRI), brain activity and structure will be examined before and after tDCS. tDCS will be administered twice daily for 5 consecutive days for a total of 10 sessions. These study findings will contribute to the understanding of the impact of tDCS on AVHs, and will also increase knowledge of sound and memory/cognitive processing in individuals with schizophrenia.

Enrollment: 84 estimated patients

Sex: All

Ages: 18 to 65 years old

Volunteers: Accepts Healthy Volunteers

Inclusion and exclusion criteria

Patients - Inclusion Criteria:

• Primary diagnosis of schizophrenia or schizoaffective disorder
• Clinically stable (discretion of psychiatrist)
• Consistent history of AVHs over the course of illness
• >3 AVHs per week
• Positive and Negative Syndrome Scale (PANSS) score of >3
• Primary medications limited to one of the atypical antipsychotics (medications stabilized for 4 weeks prior to enrollment)

Patients - Exclusion Criteria:

• Experiencing an acute psychotic episode
• Current drug/alcohol dependence
• Significant medical illness & mental retardation/learning disability
• Extra-pyramidal symptoms resulting in disordered movement
• Abnormal audiometric assessment (thresholds for pure tones >25 dB)
• History of significant neurological issues & head injuries/concussions resulting in loss of consciousness for >5 minutes

Healthy Controls - Inclusion Criteria:

• In good physical health
• No history of serious mental health issues

Healthy Controls - Exclusion Criteria:

• Personal history of psychiatric disorder
• Family history of schizophrenia in first degree relatives & history of mental health issues in first degree relatives that required extensive treatment or hospitalization
• Current/history of substance abuse
• Significant medical illness
• Extra-pyramidal symptoms resulting in movement disorder
• Abnormal audiometric assessment (thresholds for pure tones >25 dB)
• Significant neurological issues & head injuries/concussions resulting in loss of consciousness for >5 minutes

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

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84 participants in 4 patient groups

Active tDCS

Active Comparator group

Description:

Administration of a 2 milliamp (mA) current delivered via two scalp electrodes for 20 minutes (ramp-in + ramp-out periods, 30s total) 2 times per day for 5 consecutive days, \>3 hour interval between sessions, for a total of 10 tDCS sessions. tDCS will be administered with a constant current regulator (NeuroConn DC-Stimulator Plus®, Germany) using 2 saline-soaked sponge electrodes applied over the scalp. Using the 10-20 international EEG system for tDCS electrode placement, the anode will be positioned midway between F3 and Fp1 (left DLPFC) and the cathode midway between T3 and P3 (left TPJ).

Treatment:

Device: Transcranial direct current stimulation (tDCS)

Sham tDCS

Sham Comparator group

Description:

Administration of 2mA tDCS for 30 seconds followed by 19.5 minutes of no current via two scalp electrodes for 20 min (2X/day for 5 consecutive days) with \>3 hours interval between sessions, for a total of 10 tDCS sessions.

Treatment:

Device: Transcranial direct current stimulation (tDCS)

Open-label Active tDCS

Other group

Description:

Subjects who have received sham tDCS will be given the option to subsequently receive 10 sessions of open-label active tDCS (2X/day for 5 consecutive days) with \>3 hours interval between sessions, for a total of 10 tDCS sessions.

Treatment:

Device: Transcranial direct current stimulation (tDCS)

Healthy Control

No Intervention group

Description:

Healthy volunteers will complete the same questionnaires, EEG recording procedures, and neuroimaging scans as the schizophrenia patient group, but will not undergo tDCS.