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

Not Applicable
Completed
Conditions
Psychotic Disorders
Interventions
Device: DC Stimulator PLUS (NeuroConn)
Registration Number
NCT02769507
Lead Sponsor
University of Bergen
Brief Summary

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.

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.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
24
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 & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
sham tDCSDC Stimulator PLUS (NeuroConn)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.
real tDCSDC Stimulator PLUS (NeuroConn)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.
Primary Outcome Measures
NameTimeMethod
Questionnaire for Psychotic Experiences (QPE)Change from Baseline to immediately after treatment and 3 months after treatment

Measure for severity of hallucinations

Auditory Hallucination Rating Scale (AHRS)Change from Baseline to immediately after treatment and 3 months after treatment

Measure for severity of hallucinations

Hallucinations AppContinuously between baseline and 3 months after treatment

iPhone/iPod application for self-ratings of auditory hallucinations

Hallucination Change Scale (HCS)Change from Baseline to immediately after treatment and 3 months after treatment

Measure for changes in severity of auditory hallucinations

Positive and Negative Syndrome Scale (PANSS)Change from Baseline to immediately after treatment and 3 months after treatment

Measure for positive and negative symptoms in psychotic disorders

Secondary Outcome Measures
NameTimeMethod
The Clinical Global Impressions Scale - SeverityChange from Baseline to immediately after treatment and 3 months after treatment

Measure of global functioning

Adverse Effects QuestionnaireThe questionnaire is completed after each tDCS session. That is, twice on each day of the five day treatment program

The presence and severity of side-effects will be monitored using the tDCS adverse effects questionnaire

Stroop taskChange from Baseline to immediately after treatment and 3 months after treatment

Measure of executive functioning

Trailmaking test A and BChange from Baseline to immediately after treatment and 3 months after treatment

Measure of visuomotor speed

Expectations QuestionnaireChange from Baseline to immediately after treatment and 3 months after treatment

prior expectations participants have regarding the outcome of the treatment on a scale from 0 ("The treatment will have no effect") to 10 ("The treatment will make the voices go away entirely.")

BOLD (Blood Oxygenation Level Dependent signal) response during resting stateChange from Baseline to immediately after treatment and 3 months after treatment

Resting state functional MRI

Global Assessment of FunctioningChange from Baseline to immediately after treatment and 3 months after treatment

Measure of global functioning

Shape, size, and integrity of gray and white matter structures in the brainChange from Baseline to immediately after treatment and 3 months after treatment

Structural Magnetic Resonance Imaging (MRI)

GABA and glutamate levels in the dorsolateral prefrontal cortex and peri-Sylvian regionsChange from Baseline to immediately after treatment and 3 months after treatment

MR spectroscopy

Dichotic listening paradigmChange from Baseline to immediately after treatment and 3 months after treatment

Measure of language lateralization

BOLD response during dichotic listening paradigmChange from Baseline to immediately after treatment and 3 months after treatment

Changes in brain activity in the left dorsolateral prefrontal cortex and the peri-Sylvian language regions

White matter structure and connectivityChange from Baseline to immediately after treatment and 3 months after treatment

MR Diffusion Tensor Imaging

Trial Locations

Locations (1)

University of Bergen

🇳🇴

Bergen, Hordaland, Norway

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