Transcranial Direct Current Stimulation as Treatment for Auditory Hallucinations

Study Overview
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Brief Summary
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The present study aims to examine the efficacy of transcranial direct current stimulation on the severity of auditory hallucinations.

Detailed Description
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Rationale: Auditory hallucinations (AH) are a symptom of several psychiatric disorders, such as schizophrenia. In the majority of patients, these AH respond well to antipsychotic medication. Yet, a significant minority continues to experience frequent AH despite optimal pharmacotherapy and AH severely decrease quality of life in these patients. The number of alternative treatment options for this medication resistant group is currently low and most of them focus on coping with the hallucinations. Transcranial direct current stimulation (tDCS), in contrast, is a safe, non-invasive technique that is able to directly influence cortical excitability through the application of very low electric currents. This technique has only a few transient side-effects and is cheap and portable. To date, only one randomized controlled trial has been published, suggesting high efficacy of tDCS for the treatment of medication-resistant AH in a relatively small sample. We aim to replicate and extend these findings by investigating the efficacy of this technique in a larger sample.

Official Title
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Transcranial Direct Current Stimulation as Treatment for Auditory Hallucinations A Sham-controlled Trial

Conditions
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Psychotic Disorders, Mood Disorders, Personality Disorders, Stress Disorders, Post-Traumatic, Hearing Disorders

Intervention / Treatment
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* Device: Eldith DC Stimulator stimulation
* Device: Eldith DC Stimulator sham stimulation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age over 18. 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

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Treatment<br>transcranial direct current stimulation (2mA) | Device: Eldith DC Stimulator stimulation<br>* The anodal electrode will be placed with the middle of the electrode over a point midway between F3 and FP1 (left prefrontal cortex: dorsolateral prefrontal cortex and the cathodal electrode located over a point midway between T3 and P3 (left temporo-parietal junction). Stimulation will consist of 2 mA for 20 minutes per session.<br>|
| Sham Comparator: Sham<br>Sham stimulation | Device: Eldith DC Stimulator sham stimulation<br>* The anodal electrode will be placed with the middle of the electrode over a point midway between F3 and FP1 (left prefrontal cortex: dorsolateral prefrontal cortex and the cathodal electrode located over a point midway between T3 and P3 (left temporo-parietal junction). In the sham condition, after 40 seconds of real stimulation (2 mA), only a small current pulse will occur every 550 msec (110 mA over 15 msec) through the remainder of the 20-minute period.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Total score of the Auditory Hallucination Rating Scale (AHRS) questionnaire | The primary outcome is the change in the severity of the hallucinations before and after the treatment, as experienced by the participant, measured with the Auditory Hallucination Rating Scale (AHRS) | 4 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in severity of hallucinations as assessed by the hallucination change scale (HCS)questionnaire |  | 4 years | 
| Changes of positive, negative and disorganized symptomatology as assessed by the positive and negative syndrome scale (PANSS) |  | 4 years | 
| Severity of psychotic symptoms will be measured by the questionnaire for psychotic symptoms (QPS) |  | 4 years | 
| Prior expectations regarding the efficacy of the treatment of the participants |  | 4 years | 
| Strength of the motor threshold as assessed using TMS |  | 4 years | 
| The presence and severity of side-effects will be monitored using the tDCS adverse effects questionnaire |  | 4 years | 
| Interference score on the Stroop task |  | 4 years | 
| Score on the Trailmaking test A and B |  | 4 years |