Treatment Of Auditory Hallucinations Research Articles

The efficacy and safety of continuous theta burst stimulation for auditory hallucinations: a systematic review and meta-analysis of randomized controlled trials.

Auditory hallucinations are the most frequently occurring psychotic symptom in schizophrenia. Continuous theta burst stimulation (cTBS) has been used as an adjuvant treatment for auditory hallucinations. This meta-analysis focused on randomized controlled clinical trials (RCTs) to assess the efficacy of adjuvant cTBS on auditory hallucinations in schizophrenia. We performed a comprehensive search of four international databases from their inception to January 14, 2024, to identify relevant RCTs that assessed the effects of adjuvant cTBS on auditory hallucinations. The key words included "auditory hallucinations", "continuous theta burst stimulation" and "transcranial magnetic stimulation". Inclusion criteria included patients with auditory hallucinations in schizophrenia or schizoaffective disorder. The Revised Cochrane risk-of-bias tool for randomized trials (RoB1) were used to evaluate the risk of bias and the Review Manager Software Version 5.4 was employed to pool the data. A total of 4 RCTs involving 151 patients with auditory hallucinations were included in the analysis. The Cochrane risk of bias of these studies presented "low risk" in all items. Preliminary analysis showed no significant advantage of adjuvant cTBS over sham stimulation in reducing hallucinations [4 RCTs, n = 151; SMD:-0.45 (95%CI: -1.01, 0.12), P = 0.13; I2=61%]. Subgroup analysis revealed that patients treated with adjuvant cTBS for more than 10 stimulation sessions and total number of pulses more than 6000 [3 RCTs, n = 87; SMD: -4.43 (95%CI: -8.22, -0.63), P = 0.02; I2=47%] had a statistically significant improvement in hallucination symptoms. Moreover, the rates of adverse events and discontinuation did not show any significant difference between the cTBS and sham group. Although preliminary analysis did not revealed a significant advantage of adjuvant cTBS over sham stimulation, subgroup analysis showed that specific parameters of cTBS appear to be effective in the treatment of auditory hallucinations in schizophrenia. Further large-scale studies are needed to determine the standard protocol of cTBS for treating auditory hallucinations. https://www.crd.york.ac.uk/prospero/, identifier CRD42024534045.

Avatar Therapy Model and Ethical Principles in the Treatment of Auditory Hallucinations in Patients with Schizophrenia

Schizophrenia is one of the most debilitating mental disorders. Auditory hallucinations, which are known to be closely related to interpersonal relationships, are the most common type of hallucinations observed in the course of schizophrenia. Virtual reality has been developing in various fields with the development of computerized technologies and has started to appear in the field of clinical psychology in the form of virtual reality therapies. Avatar therapy is among the interpersonal-based virtual reality therapy models that focus on auditory hallucinations among the symptoms of schizophrenia. The aim of avatar therapy is to enable the person to have control over auditory hallucinations. Within the scope of this review study; the past, present and future of schizophrenia treatment, effective intervention methods in the treatment of schizophrenia, virtual reality therapy, the main outlines of the avatar therapy model, the effectiveness studies of avatar therapy and ethical issues were discussed. The results of the research on the effectiveness of avatar therapy reveal the need for further research in this field.

Enhanced Beta2-band Oscillations Denote Auditory Hallucination in Schizophrenia Patients and a Monkey Model of Psychosis.

An electroencephalographic (EEG) signature of auditory hallucinations (AHs) is important for facilitating the diagnosis and treatment of AHs in schizophrenia. We recorded EEG from 25 schizophrenia patients with recurrent AHs. During the period of AHs, EEG recordings exhibited significantly elevated beta2-band power in the temporal region, as compared to those recorded in the absence of AHs or during stimulation with verbal sounds. We further generated methamphetamine-treated rhesus monkeys exhibiting psychosis-like behaviors, including repetitive sudden searching actions in the absence of external intrusion, suggesting the occurrence of AHs. Epidural EEG beta2-band power in the temporal region of these monkeys was enhanced immediately after methamphetamine treatment and positively correlated with the frequency of sudden searching actions. Thus, the enhancement of temporal beta2-band oscillations represents a signature for AHs in both patients and a monkey model of psychosis, and this monkey model can be used for developing closed-loop neuromodulation approaches for the treatment of refractory AHs in schizophrenia.

Hallucinations in Hearing Impairment: How Informed Are Clinicians?

Patients with hearing impairment (HI) may experience hearing sounds without external sources, ranging from random meaningless noises (tinnitus) to music and other auditory hallucinations (AHs) with meaningful qualities. To ensure appropriate assessment and management, clinicians need to be aware of these phenomena. However, sensory impairment studies have shown that such clinical awareness is low. An online survey was conducted investigating awareness of AHs among clinicians and their opinions about these hallucinations. In total, 125 clinicians (68.8% audiologists; 18.4% Ear-Nose-Throat [ENT] specialists) across 10 countries participated in the survey. The majority (96.8%) was at least slightly aware of AHs in HI. About 69.6% of participants reported encountering patients with AHs less than once every 6 months in their clinic. Awareness was significantly associated with clinicians' belief that patients feel anxious about their hallucinations (β = .018, t(118) = 2.47, P < .01), their belief that clinicians should be more aware of these hallucinations (β =.018, t(118) = 2.60, P < .01), and with confidence of clinicians in their skills to assess them (β = .017, t(118) = 2.63, P < .01). Clinicians felt underequipped to treat AHs (Median = 31; U = 1838; PFDRadj < .01). Awareness of AHs among the surveyed clinicians was high. Yet, the low frequency of encounters with hallucinating patients and their belief in music as the most commonly perceived sound suggest unreported cases. Clinicians in this study expressed a lack of confidence regarding the assessment and treatment of AHs and welcome more information.

Prof K C Dube Poster Award

Background:Auditory verbal hallucinations (AVH) are one of the core features of schizophrenia. In approximately 25% of patients with schizophrenia, AVH are refractory to psychotropic drug treatment and can chronically persist. Superior temporal cortex is implicated in AVH. Continuous Theta Burst Stimulation (cTBS) can be one of the add on treatment for auditory hallucination in refractory cases. Accelerated cTBS protocols have the advantage of shorter application time and lower stimulation intensity. In addition use of robotized neuronavigation will improve the accuracy of coil placement and thus localization of the stimulation site.Aim:We aimed to evaluate the efficacy of accelerated cTBS over left superior temporal cortex (STC) in improvement of AVH in schizophrenia, using neuronavigation and robotic arm.Methods:40 patients of schizophrenia with AVH, were enrolled for this randomized, sham controlled, double-blind trial. Each participant in the active group received cTBS comprising of 900 pulses (bursts of 3 stimuli at 50 Hz repeated at 5 Hz frequency), twice a day for 5 days per week for 3 consecutive weeks. AVH were assessed with PSYRATS(AHRS), PANSS & CGI. Assessments were carried out at baseline,1st,3rd & 6th weeks.Results:The improvement in AVH in active group at 1st 3rd & 6th week was not statistically significant at 0.05 (p-value) as compared to sham group. Stimulation was well tolerated.Conclusion:Results suggest that accelerated robotized neuronavigated cTBS does not appear to have substantial potential in the treatment of auditory hallucinations and further research should investigate individualised MRI guided neuronavigation with higher sample size.

M187. A MULTIMODAL, NEUROIMAGING STUDY OF TDCS MECHANISMS RELATED TO AUDITORY VERBAL HALLUCINATIONS IN HEALTHY INDIVIDUALS

BackgroundTranscranial direct current stimulation (tDCS) is a brain stimulation method which is growing in popularity in both research and clinical settings, especially as a treatment of auditory verbal hallucinations (AVH) in patients with schizophrenia. However, the underlying neural mechanisms of this tDCS treatment are poorly understood. Current AVH models propose that AVH arise from hyperactivation in the left temporo parietal (LTPC), causing AVH, and from hypoactivation in the left dorsolateral prefrontal cortex (LDLPFC), leading to diminished control over AVH. We aimed to “mimic” this hyper-/hypoactivation pattern in healthy individuals with tDCS by placing the excitatory anode above the LTPC and the inhibitory cathode over the LDLPFC and then to study the effects of tDCS on these brain areas. Previous studies examined either brain activation, neurochemistry, or behavior, with other electrode montages, but few looked at those aspects together. The present study therefore examined tDCS effects with fMRI (functional magnetic resonance imaging), MR spectroscopy, behavioral tasks and simulation of the electric field in a multimodal approach. We hypothesized that tDCS would (a) lead to similar behavioral deficits in healthy individuals as in schizophrenia patients and (b) induce changes in the stimulated areas on neurotransmitter and functional activation level.MethodsThirty-two healthy participants (18 males, mean age=26 yrs) were tested twice, ca. one week apart, with either real or sham (control) 2mA tDCS for 20 min while in a GE 750, 3T MRI scanner. The order of real/sham stimulation was counterbalanced in a double-blind design. During fMRI, participants completed a dichotic listening task in a block design, in order to measure behavior and brain activation changes. Before and after fMRI/tDCS, MR spectroscopy was carried out in two voxels placed under the electrodes. The data was analyzed with repeated measures ANOVAs. After data-collection, the structural T1 sequence was used to simulate the electric field of tDCS stimulation.ResultsGlx (Glutamate and glutamine combined) showed a trend (F(1,31)=3.35, p=.077, η2p=.098) to increase after tDCS stimulation compared to before, however this was not electrode specific. Neither fMRI, nor the dichotic listening task (all F≤1.64, p≥.203, η2p≤.052) showed any stimulation specific differences between real and sham stimulation. The tDCS simulation revealed large individual differences in the electric field induced.DiscussionIn the present study, tDCS seemed to have little effect on the measured brain parameters and little validation for the AVH model was found. The mechanisms of tDCS and how it affects the underlying brain tissue are poorly understood and seem to be affected by different stimulation parameters like stimulation duration, current strength and electrode montage. To use tDCS most effectively in schizophrenia research and treatment of auditory hallucinations, it should be validated with a multitude of methods, similar to the approach described here.

Real-time fMRI feedback impacts brain activation, results in auditory hallucinations reduction: Part 1: Superior temporal gyrus -Preliminary evidence-

Auditory hallucinations (AH) are one of the core symptoms of schizophrenia (SZ) and constitute a significant source of suffering and disability. One third of SZ patients experience pharmacology-resistant AH, so an alternative/complementary treatment strategy is needed to alleviate this debilitating condition. In this study, real-time functional Magnetic Resonance Imaging neurofeedback (rt-fMRI NFB), a non-invasive technique, was used to teach 10 SZ patients with pharmacology-resistant AH to modulate their brain activity in the superior temporal gyrus (STG), a key area in the neurophysiology of AH. A functional task was designed in order to provide patients with a specific strategy to help them modify their brain activity in the desired direction. Specifically, they received neurofeedback from their own STG and were trained to upregulate it while listening to their own voice recording and downregulate it while ignoring a stranger's voice recording. This guided performance neurofeedback training resulted in a) a significant reduction in STG activation while ignoring a stranger's voice, and b) reductions in AH scores after the neurofeedback session. A single, 21-minute session of rt-fMRI NFB was enough to produce these effects, suggesting that this approach may be an efficient and clinically viable alternative for the treatment of pharmacology-resistant AH.

Examining tDCS as a treatment for auditory hallucinations in adolescents with childhood-onset schizophrenia. A pilot, proof of principle open study

Auditory hallucinations (AH) are very frequent and disabling symptoms of schizophrenia. In 25% to 30% of these patients, AH will stay refractory to conventional medication, resulting in persistent distress and functional disability. In such cases, evidences suggest that transcranial direct current stimulation (tDCS) could improve AH in adults with schizophrenia. tDCS is a safe noninvasive brain stimulation technique that might modulate brain activity and connectivity in the living Humans. AH are also frequently reported in patients with childhood-onset schizophrenia (COS). While pharmacological treatment of AH in adolescents with COS often leads to multiple side effects, little is known regarding the clinical interest of tDCS in adolescents with AH. The aim of this pilot study is to evaluate the safety and the clinical interest of a tDCS in the treatment of refractory AH in adolescents with COS. In an open-label prospective study, adolescents with COS and refractory AH will received 10 sessions (twice a day for 5 consecutive weekdays) of tDCS (30 minutes, 2 mA). The anode will be placed over the left dorsolateral prefrontal cortex and the cathode over the left temporo-parietal cortex. The severity of AH and the functioning of patients will be assessed 4 times using the Auditory Hallucinations Rating Scale (AHRS), and the Global Assessment of Functioning (GAF): at baseline (V1), after tDCS sessions (V2), one (V3) and 3 months later (V4). Preliminary results in 6 patients showed that tDCS may alleviate AH severity and that tDCS is a safe approach in adolescents with COS. AHRS scores exhibited a 66% decrease (from mean = 25.1 ± standard deviation 3.8 to 8.1 ± 12.8 one month later after tDCS). The Friedman Test for Repeated-Measures indicated a significant effect of tDCS on AH measured with the AHRS; chi square = 9; P = .01. We also observed a significant improvement of functioning measured with the GAF scores in adolescents with COS and refractory AH. Further randomized controlled studies are needed to confirm these preliminary results.

Repetitive transcranial magnetic stimulation treatment for auditory hallucinations: Personalized or standardized targets?

Introduction Most repetitive transcranial magnetic stimulation (rTMS) studies aiming to reduce auditory verbal hallucinations (AVH) in schizophrenia target the left temporo-parietal junction (TPJ), but the efficacy of this approach remains controversial. The observed differences in efficacy could be attributed to inaccurate target localization. The two possible approaches for rTMS target localization are the Standardized Target (ST) T3P3 method and the Personalized Target (PT) method including functional or anatomical brain imaging. Recent large, parallel, double-blinded and sham-controlled studies delivering rTMS with individualized neuronavigation over Wernicke's region showed consistent improvements in AVH. Methods The purpose of this study is to compare ST and PT locations within the left TPJ. An open-source tool (GeodesicSlicer) was developed to compare the geodesic distances between stimulation site determination methods. Results This study reports a differential of approximately 3 cm between personalized and standardized methods, with the potential to explain the dissonant results found in previous rTMS studies.

MRI and brain stimulation in common practice: Toward precision medicine

Background Repetitive transcranial magnetic stimulation (rTMS) is a validated treatment for patients with depression resistant to antidepressant medication. To a lesser extent, rTMS is considered as a second-line treatment for auditory hallucinations in patients with schizophrenia resistant to antipsychotic medication. However, roughly 50% of patients with resistant depression are not responding to TMS. Thus, finding predictive factors for rTMS response is key to offer personalized treatment to patients. Drysdale et al. [1] have proposed that combining clinical characteristics and functional MRI could lead to the prediction of TMS outcome in patients with depression. However, there is still a limited access to functional MRI in common practice. Structural MRI is an accessible and short duration exam used in common practice for neuronavigation purposes. Methods We conducted a neuroimaging retrospective study in our center and analyzed structural MRI of patients treated both in open label and randomized trials for resistant depression and hallucinations. We processed structural MRI with FreeSurfer software, which provide an automated segmentation of the brain. All MRI were acquired with the same neuroimaging protocol. We compared both skull and brain anatomical features in patients responding and not responding to rTMS. Results We here present preliminary results of our study and demonstrate the feasibility of analyzing structural MRI in the context of brain stimulation in common practice. We discuss MRI-based potential factors that could be taken into account to understand rTMS response.

A Computational Assessment of Target Engagement in the Treatment of Auditory Hallucinations with Transcranial Direct Current Stimulation.

We use auditory verbal hallucinations (AVH) to illustrate the challenges in defining and assessing target engagement in the context of transcranial direct current stimulation (tDCS) for psychiatric disorders. We defined the target network as the cluster of regions of interest (ROIs) that are consistently implicated in AVH based on the conjunction of multimodal meta-analytic neuroimaging data. These were prescribed in the New York Head (a population derived model) and head models of four single individuals. We appraised two potential measures of target engagement, tDCS-induced peak electric field strength and tDCS-modulated volume defined as the percentage of the volume of the AVH network exposed to electric field magnitude stronger than the postulated threshold for neuronal excitability. We examined a left unilateral (LUL) montage targeting the prefrontal cortex (PFC) and temporoparietal junction (TPJ), a bilateral (BL) prefrontal montage, and a 2 × 1 montage targeting the left PFC and the TPJ bilaterally. Using computational modeling, we estimated the peak electric field strength and modulated volume induced by each montage for current amplitudes ranging 1–4 mA. We found that the LUL montage was inferior to both other montages in terms of peak electric field strength in right-sided AVH-ROIs. The BL montage was inferior to both other montages in terms of modulated volume of the left-sided AVH-ROIs. As the modulated volume is non-linear, its variability between montages reduced for current amplitudes above 3 mA. These findings illustrate how computational target engagement for tDCS can be tailored to specific networks and provide a principled approach for future study design.

Treatment of auditory hallucinations with bilateral theta burst stimulation (cTBS): protocol of a randomized, double-blind, placebo-controlled, multicenter trial.

ClinicalTrials.gov identifier: NCT02670291.

P012 Unexpected improvement of motor function in a stroke patient following an rTMS treatment for auditory hallucinations: a case report

Introduction Auditory verbal hallucinations (AVHs) are perception-like experiences that occur without an external stimulus. AVHs can occur following a stroke. Repetitive Transcranial Magnetic Stimulation (rTMS) is a tool used to induce brain plasticity in local and remote areas of the brain that may be used for AVHs treatment. Here, we report the case of a patient experiencing AVHs following a stroke treated with rTMS applied to the left temporoparietal junction. Objective To treat AVHs in a post-stroke incomplete locked-in patient with rTMS. Patient and methods Following a stroke event, an MRI revealed bilateral lesions in a 55-year-old male brain (large lesion from the bulbo-pontine junction to the cerebral peduncles, and small lesions in the right cerebellar and the left capsulo-thalamic regions). The patient developed an incomplete locked-in syndrome and he experienced AVHs and delusional melancholia six years after the insult. An antipsychotic treatment was not tolerated well and, consequently, an experimental treatment by rTMS was applied to this patient to ameliorate these symptoms. To this purpose, an inhibitory 1-Hz rTMS protocol was delivered twice per day, with an interval of 1 h and an intensity of 100% of his resting Motor Threshold of the left hemisphere. Each session lasted 20 min and delivered 1200 pulses. In total, 56 rTMS sessions were administered. AVHs and mood were assessed using the Auditory Hallucinations Rating Scale (AHRS), the Beck Depression Inventory (BDI) and the Hospital Anxiety and Depression scale (HAD) before and during the treatment. Results After 26 sessions of the 1-Hz rTMS, the AHRS score was reduced from 29 to 0, indicating the absence of AVHs. A reduction of BDI and HAD scores showed an improvement in mood. In addition, there was an unexpected improvement of motor function in the contralateral hand to the stimulated region. Conclusion Repetitive TMS should be considered as a therapeutic option for AVHs following a stroke. Potential associated motor improvement that stimulation could unfold provides additional value to the use of rTMS such clinical scenario. Further investigations are underway to understand the brain plasticity mechanisms underlying such unexpected motor improvement.

Use of transcranial direct current stimulation for the treatment of auditory hallucinations of schizophrenia - a systematic review.

IntroductionAuditory hallucinations are defined as experiences of auditory perceptions in the absence of a provoking external stimulus. They are the most prevalent symptoms of schizophrenia with high capacity for chronicity and refractoriness during the course of disease. The transcranial direct current stimulation (tDCS) – a safe, portable, and inexpensive neuromodulation technique – has emerged as a promising treatment for the management of auditory hallucinations.ObjectiveThe aim of this study is to analyze the level of evidence in the literature available for the use of tDCS as a treatment for auditory hallucinations in schizophrenia.MethodsA systematic review was performed, searching in the main electronic databases including the Cochrane Library and MEDLINE/PubMed. The searches were performed by combining descriptors, applying terms of the Medical Subject Headings (MeSH) of Descriptors of Health Sciences and descriptors contractions. PRISMA protocol was used as a guide and the terms used were the clinical outcomes (“Schizophrenia” OR “Auditory Hallucinations” OR “Auditory Verbal Hallucinations” OR “Psychosis”) searched together (“AND”) with interventions (“transcranial Direct Current Stimulation” OR “tDCS” OR “Brain Polarization”).ResultsSix randomized controlled trials that evaluated the effects of tDCS on the severity of auditory hallucinations in schizophrenic patients were selected. Analysis of the clinical results of these studies pointed toward incongruence in the information with regard to the therapeutic use of tDCS with a view to reducing the severity of auditory hallucinations in schizophrenia. Only three studies revealed a therapeutic benefit, manifested by reductions in severity and frequency of auditory verbal hallucinations in schizophrenic patients.ConclusionAlthough tDCS has shown promising results in reducing the severity of auditory hallucinations in schizophrenic patients, this technique cannot yet be used as a therapeutic alternative due to lack of studies with large sample sizes that portray the positive effects that have been described.

Effects of Transcranial Direct Current Stimulation (tDCS) for Auditory Hallucinations: A Systematic Review.

BackgroundTranscranial direct current stimulation (tDCS) is a non-invasion brain stimulation, which has been suggested as a safe and promising treatment for auditory hallucinations, however, no systematic review has been conducted to evaluate the effects of tDCS on auditory hallucinations (AH).ObjectiveTo investigate the efficacy and safety of tDCS for auditory hallucinations among patients with schizophrenia.MethodsWe searched relevant randomized controlled trials (RCTs) from PubMed, EMBASE, the Cochrane Library, Chinese National Knowledge Infrastructure, Chongqing VIP database for Chinese Technical Periodicals, WANFANG DATA, Chinese Biological Medical Literature Database, and Taiwan Electronic Periodical Services (TEPS) before February 13, 2016. Studies were selected based on pre-defined inclusion and exclusion criteria. The quality of each included study was assessed by the risk of bias table. The levels of evidence of primary outcomes were evaluated using GRADE criteria. Data synthesis was conducted using RevMan 5.3.Results304 papers were screened. Finally, three studies with a combined sample size of 87 patients were included in the meta-analysis. Two studies were classified as having ‘low risk of bias’, one study was classified as having ‘unclear’. Inconsistent results and the overall level of evidence of primary outcome was graded as ‘low’.ConclusionsThe sample sizes of the published studies were small and the results were inconsistent. We could not draw any strong conclusions from these trials. Further high quality RCTs with large sample sizes are needed to assess the efficacy of tDCS for auditory hallucinations in patients with schizophrenia.

How increasing the effect of rTMS in the treatment of auditory hallucinations in schizophrenia?

Repetitive transcranial magnetic stimulation (rTMS) shows a high inter-subjects variability in the efficacy of treatment of auditory verbal hallucinations (AVH) in schizophrenia. The aim of this presentation is to demonstrate the involvement of several factors in the efficacy of rTMS such as the frequency of stimulation, the placebo effect and the brain morphology underlying the target of stimulation.MethodsA meta-analysis was conducted to determine the effect sizes of placebo effect in 21 controlled studies on rTMS in the treatment of AVH in schizophrenia. MRI was also acquired in patients treated by rTMS to evaluate the scalp to cortex distances (SDCs) and the gray matter densities (GMDs) at the target of stimulation. Finally, we evaluated the efficacy of high (20 Hz) frequency stimulation in a controlled placebo study.ResultsWeak or no placebo effect in the control groups led to reveal a superiority of active rTMS over sham rTMS in the treatment of AVH. Clinical efficacy of rTMS was also correlated with the SCD or the GMD at the region of the target stimulation. Finally, we also demonstrated that more responders were observed after 2 weeks in the active group treated by 20 Hz than in the placebo group.ConclusionWe clearly demonstrated that several factors such as high frequency, the placebo effect, anatomical cortical variations can impact on the efficacy of rTMS. These results fundamentally inform the design and the method of further controlled studies, particularly with respect to studies of rTMS in the treatment of AVH.Disclosure of interestThe authors have not supplied their declaration of competing interest.

Exploratory study of once-daily transcranial direct current stimulation (tDCS) as a treatment for auditory hallucinations in schizophrenia

BackgroundAuditory hallucinations are resistant to pharmacotherapy in about 25% of adults with schizophrenia. Treatment with noninvasive brain stimulation would provide a welcomed additional tool for the clinical management of auditory hallucinations. A recent study found a significant reduction in auditory hallucinations in people with schizophrenia after five days of twice-daily transcranial direct current stimulation (tDCS) that simultaneously targeted left dorsolateral prefrontal cortex and left temporo-parietal cortex. HypothesisWe hypothesized that once-daily tDCS with stimulation electrodes over left frontal and temporo-parietal areas reduces auditory hallucinations in patients with schizophrenia. MethodsWe performed a randomized, double-blind, sham-controlled study that evaluated five days of daily tDCS of the same cortical targets in 26 outpatients with schizophrenia and schizoaffective disorder with auditory hallucinations. ResultsWe found a significant reduction in auditory hallucinations measured by the Auditory Hallucination Rating Scale (F2,50=12.22, P<0.0001) that was not specific to the treatment group (F2,48=0.43, P=0.65). No significant change of overall schizophrenia symptom severity measured by the Positive and Negative Syndrome Scale was observed. ConclusionsThe lack of efficacy of tDCS for treatment of auditory hallucinations and the pronounced response in the sham-treated group in this study contrasts with the previous finding and demonstrates the need for further optimization and evaluation of noninvasive brain stimulation strategies. In particular, higher cumulative doses and higher treatment frequencies of tDCS together with strategies to reduce placebo responses should be investigated. Additionally, consideration of more targeted stimulation to engage specific deficits in temporal organization of brain activity in patients with auditory hallucinations may be warranted.

Use of Repetitive Transcranial Magnetic Stimulation for Treatment of Auditory Hallucinations: A Case Report and Brief Review

Use of Repetitive Transcranial Magnetic Stimulation for Treatment of Auditory Hallucinations: A Case Report and Brief Review

Transcranial direct current stimulation as a treatment for auditory hallucinations.

Auditory hallucinations (AH) are a symptom of several psychiatric disorders, such as schizophrenia. In a significant minority of patients, AH are resistant to antipsychotic medication. Alternative treatment options for this medication resistant group are scarce and most of them focus on coping with the hallucinations. Finding an alternative treatment that can diminish AH is of great importance. Transcranial direct current stimulation (tDCS) is a safe and non-invasive technique that is able to directly influence cortical excitability through the application of very low electric currents. A 1–2 mA direct current is applied between two surface electrodes, one serving as the anode and the other as the cathode. Cortical excitability is increased in the vicinity of the anode and reduced near the cathode. The technique, which has only a few transient side effects and is cheap and portable, is increasingly explored as a treatment for neurological and psychiatric symptoms. It has shown efficacy on symptoms of depression, bipolar disorder, schizophrenia, Alzheimer’s disease, Parkinson’s disease, epilepsy, and stroke. However, the application of tDCS as a treatment for AH is relatively new. This article provides an overview of the current knowledge in this field and guidelines for future research.

Factors influencing the efficacy of rTMS in the treatment of auditory hallucinations

Repetitive transcranial magnetic stimulation (rTMS) shows a high inter-subjects variability in the efficacy of the treatment of resistant auditory verbal hallucinations (AVH) in schizophrenia, but causal factors of this variability are not known. Focal anatomical alterations of the left temporal cortex that is targeted in the rTMS treatment are well demonstrated, and could be one cause of this variability, but they are not taken into account in the treatment procedure.