Short and long term effects of left and bilateral repetitive transcranial magnetic stimulation in schizophrenia patients with auditory verbal hallucinations: a randomized controlled trial

Investigating the effect of rTMS over the temporoparietal cortex on the Right Ear Advantage for perceived and imagined voices

A Right Ear Advantage (REA) is well-established in perceptual tasks but it has been found also during imagery. It is ascribed to the left temporoparietal activity for language, and it can be absent/reversed in some clinical conditions including auditory hallucinations. We applied 1-Hz repetitive TMS over TP3/TP4 (left/right language areas) identified through neuronavigation in 18 healthy participants, before administering a modified white noise (WN) speech illusion paradigm: a voice was presented at one ear, at the same or lower intensities with respect to binaural WN. In some trials the voice was not presented, but participants were anyway instructed to report in which ear they believed perceiving it in all trials. Results confirmed the REA both when the voice was present (perceptual REA) and when it was absent (imaginative REA). Interestingly, results suggested that the correct localization of the voice when the stimulus was ambiguous (presented at low intensity and "masked" by WN) was better when TMS was applied over the right/left hemisphere, in male participants with a low/high proneness to unusual experiences (e.g., auditory hallucinations), respectively. This interaction must be further explored to shed light on the relationship between hemispheric asymmetries and auditory hallucinations, in healthy and clinical samples.

Transcranial Magnetic Stimulation and Transcranial Direct Current Stimulation Across Mental Disorders: A Systematic Review and Dose-Response Meta-Analysis

Importance

Noninvasive brain stimulation (NIBS) interventions have been shown to be efficacious in several mental disorders, but the optimal dose stimulation parameters for each disorder are unknown.

Objective

To define NIBS dose stimulation parameters associated with the greatest efficacy in symptom improvement across mental disorders.

Data Sources

Studies were drawn from an updated (to April 30, 2023) previous systematic review based on a search of PubMed, OVID, and Web of Knowledge.

Study Selection

Randomized clinical trials were selected that tested transcranial magnetic stimulation (TMS) or transcranial direct current stimulation (tDCS) for any mental disorder in adults aged 18 years or older.

Data Extraction and Synthesis

Two authors independently extracted the data. A 1-stage dose-response meta-analysis using a random-effects model was performed. Sensitivity analyses were conducted to test robustness of the findings. This study followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline.

Main Outcomes and Measures

The main outcome was the near-maximal effective doses of total pulses received for TMS and total current dose in coulombs for tDCS.

Results

A total of 110 studies with 4820 participants (2659 men [61.4%]; mean [SD] age, 42.3 [8.8] years) were included. The following significant dose-response associations emerged with bell-shaped curves: (1) in schizophrenia, high-frequency (HF) TMS on the left dorsolateral prefrontal cortex (LDLPFC) for negative symptoms (χ2 = 9.35; df = 2; P = .009) and TMS on the left temporoparietal junction for resistant hallucinations (χ2 = 36.52; df = 2; P < .001); (2) in depression, HF-DLPFC TMS (χ2 = 14.49; df = 2; P < .001); (3) in treatment-resistant depression, LDLPFC tDCS (χ2 = 14.56; df = 2; P < .001); and (4) in substance use disorder, LDLPFC tDCS (χ2 = 33.63; df = 2; P < .001). The following significant dose-response associations emerged with plateaued or ascending curves: (1) in depression, low-frequency (LF) TMS on the right DLPFC (RDLPFC) with ascending curve (χ2 = 25.67; df = 2; P = .001); (2) for treatment-resistant depression, LF TMS on the bilateral DLPFC with ascending curve (χ2 = 5.86; df = 2; P = .004); (3) in obsessive-compulsive disorder, LF-RDLPFC TMS with ascending curve (χ2 = 20.65; df = 2; P < .001) and LF TMS on the orbitofrontal cortex with a plateaued curve (χ2 = 15.19; df = 2; P < .001); and (4) in posttraumatic stress disorder, LF-RDLPFC TMS with ascending curve (χ2 = 54.15; df = 2; P < .001). Sensitivity analyses confirmed the main findings.

Conclusions and Relevance

The study findings suggest that NIBS yields specific outcomes based on dose parameters across various mental disorders and brain regions. Clinicians should consider these dose parameters when prescribing NIBS. Additional research is needed to prospectively validate the findings in randomized, sham-controlled trials and explore how other parameters contribute to the observed dose-response association.

Heterogeneous Brain Abnormalities in Schizophrenia Converge on a Common Network Associated With Symptom Remission

BACKGROUND AND HYPOTHESIS

There is a huge heterogeneity of magnetic resonance imaging findings in schizophrenia studies. Here, we hypothesized that brain regions identified by structural and functional imaging studies of schizophrenia could be reconciled in a common network.

STUDY DESIGN

We systematically reviewed the case-control studies that estimated the brain morphology or resting-state local function for schizophrenia patients in the literature. Using the healthy human connectome (n = 652) and a validated technique "coordinate network mapping" to identify a common brain network affected in schizophrenia. Then, the specificity of this schizophrenia network was examined by independent data collected from 13 meta-analyses. The clinical relevance of this schizophrenia network was tested on independent data of medication, neuromodulation, and brain lesions.

STUDY RESULTS

We identified 83 morphological and 60 functional studies comprising 7389 patients with schizophrenia and 7408 control subjects. The "coordinate network mapping" showed that the atrophy and dysfunction coordinates were functionally connected to a common network although they were spatially distant from each other. Taking all 143 studies together, we identified the schizophrenia network with hub regions in the bilateral anterior cingulate cortex, insula, temporal lobe, and subcortical structures. Based on independent data from 13 meta-analyses, we showed that these hub regions were specifically connected with regions of cortical thickness changes in schizophrenia. More importantly, this schizophrenia network was remarkably aligned with regions involving psychotic symptom remission.

CONCLUSIONS

Neuroimaging abnormalities in cross-sectional schizophrenia studies converged into a common brain network that provided testable targets for developing precise therapies.

Effectiveness of Prefrontal Transcranial Magnetic Stimulation for Depression in Older US Military Veterans

OBJECTIVE

While typical aging is associated with decreased cortical volume, major depressive disorder (MDD) and posttraumatic stress disorder (PTSD) likely exacerbates this process. Cerebral atrophy leads to increased coil-to-cortex distance and when using transcranial magnetic stimulation (TMS), potentially reducing effectiveness in older adults.

METHODS

Data from a large-scale quality improvement project was used. Included veterans eligible for TMS and completed TMS treatment. Age was assessed as a predictive factor of depression outcomes after TMS treatment among veterans. Secondary analyses examined the impact of age on 1) MDD response and remission and 2) MDD change within MDD-only verses comorbid MDD and PTSD groups.

RESULTS

The entire sample included 471 veterans. Primary analysis revealed age as a negative predictor of depression outcomes (p = 0.019). Secondary analyses found age to be a significant predictor of remission (p = 0.004), but not clinical response. Age was not a predictive factor in depression outcomes between those with MDD-only compared to MDD+PTSD.

CONCLUSIONS

Increased age predicts greater MDD symptom reduction after TMS. Although age did not predict response rates, it did predict increased rates of remission in veterans. Age did not differentially predict depression outcomes between those with or without PTSD. The sample size was sufficient to discern a difference in efficaciousness, and limitations were those inherent to registry studies in veterans. This data indicates that TMS can be an important treatment option for older individuals.

From Molecule to Patient Rehabilitation: The Impact of Transcranial Direct Current Stimulation and Magnetic Stimulation on Stroke-A Narrative Review

Stroke is a major health problem worldwide, with numerous health, social, and economic implications for survivors and their families. One simple answer to this problem would be to ensure the best rehabilitation with full social reintegration. As such, a plethora of rehabilitation programs was developed and used by healthcare professionals. Among them, modern techniques such as transcranial magnetic stimulation and transcranial direct current stimulation are being used and seem to bring improvements to poststroke rehabilitation. This success is attributed to their capacity to enhance cellular neuromodulation. This modulation includes the reduction of the inflammatory response, autophagy suppression, antiapoptotic effects, angiogenesis enhancement, alterations in the blood-brain barrier permeability, attenuation of oxidative stress, influence on neurotransmitter metabolism, neurogenesis, and enhanced structural neuroplasticity. The favorable effects have been demonstrated at the cellular level in animal models and are supported by clinical studies. Thus, these methods proved to reduce infarct volumes and to improve motor performance, deglutition, functional independence, and high-order cerebral functions (i.e., aphasia and heminegligence). However, as with every therapeutic method, these techniques can also have limitations. Their regimen of administration, the phase of the stroke at which they are applied, and the patients' characteristics (i.e., genotype and corticospinal integrity) seem to influence the outcome. Thus, no response or even worsening effects were obtained under certain circumstances both in animal stroke model studies and in clinical trials. Overall, weighing up risks and benefits, the new transcranial electrical and magnetic stimulation techniques can represent effective tools with which to improve the patients' recovery after stroke, with minimal to no adverse effects. Here, we discuss their effects and the molecular and cellular events underlying their effects as well as their clinical implications.

[Augmentation therapy of resistant schizophrenia with rhythmic transcranial magnetic stimulation]

OBJECTIVE

To identify the clinical efficacy of rhythmic transcranial magnetic stimulation (rTMS) in resistant schizophrenia.

MATERIAL AND METHODS

The study included 44 male patients with resistant schizophrenia, divided into 4 groups: with depressive (group 1; n=11, 25.0%), with hallucinatory (group 2; n=12, 27.3%), with negative (group 3; n=11, 25.0%) and with delusional symptoms (group 4; n=10, 22.7%). Patients received rTMS, the parameters of which were determined depending on the typological variety, for 3 weeks (15 sessions). Psychometric assessment was carried with PANSS, CGI-S, CGI-I, SANS, CDSS, AHRS when included in the study (0 day), after stimulation (21 days) and by the end of the study (42 day) that allowed evaluation of both the severity of the therapeutic effect and its duration.

RESULTS

By the end of the course of stimulation, patients of the first three groups developed a distinct positive effect corresponding to a significant reduction in the total PANSS score: group 1 - 24.4% (p=0.002), group 2 - 8.3% (p=0.02), group 3 - 11.7% (p=0.001), which remained stable by day 42 in patients of the first (p=0.001) and second (p=0.005) groups. In patients with delusional symptoms (group 4), a subpsychotic state developed with a corresponding increase in the total PANSS score by 9.7% (p=0.007) requiring a course of relief therapy, which showed effectiveness by the end of the observation (day 42), indicating that resistance was overcome.

CONCLUSION

The study demonstrated the validity of rTMS as an adjuvant method of treatment in the resistant schizophrenia. To implement the potential of rTMS, it is necessary first of all to take into account the structural features of the condition, as well as to continue improving the stimulation technique itself (increasing the duration of the course, developing supportive courses).

Twice daily low frequency rTMS for treatment-resistant auditory hallucinations

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) has emerged as a therapeutic solution in patients with treatment-resistant auditory verbal hallucinations. However, the optimal stimulation parameters remain unclear, especially for patients with clozapine-resistant symptoms.

METHOD

In an open label retrospective study, we investigated whether parameters of stimulation that were useful in patients with major depressive disorder would help schizophrenia patients with treatment-resistant auditory verbal hallucinations. Fourteen participants, including 9 under clozapine, received 30 sessions of 1 Hz rTMS over 3 weeks (360 pulses per sessions delivered with 60 s 'on' and 30 s 'off' at 110% of the resting motor threshold, 2 sessions per day). Stimulations were applied over the left temporoparietal junction (T3-P3 according to 10/20 system).

RESULTS

After rTMS, a significant decrease of auditory verbal hallucinations was observed (-38.7% ± 31.8, p = 0.003) on the Auditory Hallucination Rating Scale. The beneficial effects were also significant in the 9 patients who were also receiving clozapine (-34.9% ± 28.4, p = 0.01).

CONCLUSIONS

Low frequency rTMS, 30 sessions over 3 weeks, appears to be a suitable approach to decrease treatment-resistant auditory verbal hallucinations, including in patients with clozapine-resistant symptoms. Results from the current retrospective study in the clinical settings need to be confirmed by large-scale randomized sham-controlled trials.

A transdiagnostic review of safety, efficacy, and parameter space in accelerated transcranial magnetic stimulation

BACKGROUND

Accelerated transcranial magnetic stimulation (aTMS) is an emerging delivery schedule of repetitive TMS (rTMS). TMS is "accelerated" by applying two or more stimulation sessions within a day. This three-part review comprehensively reports the safety/tolerability, efficacy, and stimulation parameters affecting response across disorders.

METHODS

We used the PubMed database to identify studies administering aTMS, which we defined as applying at least two rTMS sessions within one day.

RESULTS

Our targeted literature search identified 85 aTMS studies across 18 diagnostic and healthy control groups published from July 2001 to June 2022. Excluding overlapping populations, 63 studies delivered 43,873 aTMS sessions using low frequency, high frequency, and theta burst stimulation in 1543 participants. Regarding safety, aTMS studies had similar seizure and side effect incidence rates to those reported for once daily rTMS. One seizure was reported from aTMS (0.0023% of aTMS sessions, compared with 0.0075% in once daily rTMS). The most common side effects were acute headache (28.4%), fatigue (8.6%), and scalp discomfort (8.3%), with all others under 5%. We evaluated aTMS efficacy in 23 depression studies (the condition with the most studies), finding an average response rate of 42.4% and remission rate of 28.4% (range = 0-90.5% for both). Regarding parameters, aTMS studies ranged from 2 to 10 sessions per day over 2-30 treatment days, 10-640 min between sessions, and a total of 9-104 total accelerated TMS sessions per participant (including tapering sessions). Qualitatively, response rate tends to be higher with an increasing number of sessions per day, total sessions, and total pulses.

DISCUSSION

The literature to date suggests that aTMS is safe and well-tolerated across conditions. Taken together, these early studies suggest potential effectiveness even in highly treatment refractory conditions with the added potential to reduce patient burden while also expediting response time. Future studies are warranted to systematically investigate how key aTMS parameters affect treatment outcome and durability.

Efficacy of neurostimulation across mental disorders: systematic review and meta-analysis of 208 randomized controlled trials

Non-invasive brain stimulation (NIBS), including transcranial magnetic stimulation (TMS), and transcranial direct current stimulation (tDCS), is a potentially effective treatment strategy for a number of mental conditions. However, no quantitative evidence synthesis of randomized controlled trials (RCTs) of TMS or tDCS using the same criteria including several mental conditions is available. Based on 208 RCTs identified in a systematic review, we conducted a series of random effects meta-analyses to assess the efficacy of NIBS, compared to sham, for core symptoms and cognitive functioning within a broad range of mental conditions. Outcomes included changes in core symptom severity and cognitive functioning from pre- to post-treatment. We found significant positive effects for several outcomes without significant heterogeneity including TMS for symptoms of generalized anxiety disorder (SMD = -1.8 (95% CI: -2.6 to -1), and tDCS for symptoms of substance use disorder (-0.73, -1.00 to -0.46). There was also significant effects for TMS in obsessive-compulsive disorder (-0.66, -0.91 to -0.41) and unipolar depression symptoms (-0.60, -0.78 to -0.42) but with significant heterogeneity. However, subgroup analyses based on stimulation site and number of treatment sessions revealed evidence of positive effects, without significant heterogeneity, for specific TMS stimulation protocols. For neurocognitive outcomes, there was only significant evidence, without significant heterogeneity, for tDCS for improving attention (-0.3, -0.55 to -0.05) and working memory (-0.38, -0.74 to -0.03) in individuals with schizophrenia. We concluded that TMS and tDCS can benefit individuals with a variety of mental conditions, significantly improving clinical dimensions, including cognitive deficits in schizophrenia which are poorly responsive to pharmacotherapy.

Assessment of treatment resistance criteria in non-invasive brain stimulation studies of schizophrenia

Novel treatment modalities, such as non-invasive brain stimulation (NIBS), typically focus on patient groups that have failed multiple treatment interventions. Despite its promise, the clinical translation of NIBS in schizophrenia has been limited. One important obstacle to implementation is the inconsistent reporting of treatment resistance in the clinical trial literature contributing to heterogeneity in reported effects. In response, we develop a numerical approach to synthesize quality of assessment of Treatment-Resistant Schizophrenia (TRS) and apply this to studies investigating therapeutic response to NIBS in patients with schizophrenia. Literature search conducted through PubMed database identified 119 studies investigating Transcranial Magnetic Stimulation and Transcranial Electrical Stimulation in treating resistant schizophrenia symptoms. A quality score out of 11 was assigned to each study based on adherence to the international consensus guidelines for TRS developed by the Treatment Response and Resistance in Psychosis (TRRIP) group. Results revealed an overall paucity of studies with thorough assessment and/or reporting of TRS phenomenon, as evidenced by a mean quality score of 3.38/11 (SD: 1.01) for trials and 5.16/11 (SD: 1.57) for case reports, though this improved minimally since the publication of consensus criteria. Most studies considered treatment-resistance as a single dimensional construct by reporting resistance of a single symptom, and failed to establish treatment adherence, resistance time course and functional impairment. We conclude that the current NIBS literature in schizophrenia do not reflect its true effects on treatment-resistance. There is an urgent need to improve assessment and reporting standards of clinical trials that target TRS.

The efficacy of transcranial magnetic stimulation (TMS) for negative symptoms in schizophrenia: a systematic review and meta-analysis

Several trials have shown preliminary evidence for the efficacy of transcranial magnetic stimulation (TMS) as a treatment for negative symptoms in schizophrenia. Here, we synthesize this literature in a systematic review and quantitative meta-analysis of double-blind randomized controlled trials of TMS in patients with schizophrenia. Specifically, MEDLINE, EMBASE, Web of Science, and PsycINFO were searched for sham-controlled, randomized trials of TMS among patients with schizophrenia. The effect of TMS vs. sham on negative symptoms in each study was quantified by the standardized mean difference (SMD, Cohen's d) with 95% confidence intervals (95%CI) and pooled across studies using an inverse variance random effects model. We identified 57 studies with a total of 2633 participants that were included in the meta-analysis. The pooled analysis showed statistically significant superiority of TMS (SMD = 0.41, 95%CI: 0.26; 0.56, p-value < 0.001), corresponding to a number needed to treat of 5. Furthermore, stratified analyses suggested that TMS targeting the left dorsolateral prefrontal cortex and using a stimulation frequency >1 Hz was most efficacious. There was, however, substantial heterogeneity and high risk of bias among the included studies. In conclusion, TMS appears to be an efficacious treatment option for patients with schizophrenia suffering from negative symptoms, but the optimal TMS parameters are yet to be established.

Cost-utility analysis of rTMS as add-on therapy to standard care for the treatment of hallucinations in schizophrenia

Background

This research evaluates the cost-effectiveness of repetitive transcranial magnetic stimulation (rTMS) as add-on therapy to standard care for adults with schizophrenia from an Australian health system perspective.

Methods

A Markov model estimated costs in 2021 Australian dollars and Disability-Adjusted Life-Years (DALYs) averted with rTMS added to standard care compared to standard care alone over 12-months for adults aged 25–65 years with hallucinations in schizophrenia refractory to other therapies. rTMS effect size was sourced from a meta-analysis and converted to a relative risk using the Cochrane conversion method. Probabilistic sensitivity analysis evaluated uncertainty in effect size and disability weights. One-way sensitivity analyses varied rTMS session cost and effectiveness, time horizon and inpatient costs.

Results

The base-case average incremental cost-effectiveness ratio (ICER) was $87,310/DALY averted (95% UI: $10,157–$97,877). Reducing rTMS session cost to $100 lowered the ICER to $9,127/DALY (95% UI: Dominant–$50,699). A 4-year time horizon resulted in rTMS being less costly and more effective (Dominant) than standard care. Decreasing the 3-month probability of relapse with rTMS to 4.6% resulted in a 71% probability of rTMS being cost-effective.

Conclusions

Using a threshold of $50,000/ DALY averted, rTMS as add-on therapy to standard care for the treatment of refractory hallucinations in schizophrenia would not be considered a cost-effective treatment option compared to standard care alone. However, given the refractory nature of this condition and the relatively small size of this population, it may be reasonable for decision-makers to adopt a higher ICER threshold.

The alternations of nucleus accumbent in schizophrenia patients with auditory verbal hallucinations during low-frequency rTMS treatment

Low-frequency repetitive transcranial magnetic stimulation (rTMS) has been shown to reduce the severity of auditory verbal hallucinations (AVH) and induce beneficial functional and structural alternations of the brain in schizophrenia patients with AVH. The nucleus accumbens (NAcc) as an important component of the ventral striatum is implicated with the pathology in AVH. However, the induced characteristic patterns of NAcc by low-frequency rTMS in schizophrenia with AVH are seldom explored. We investigated the functional and structural characteristic patterns of NAcc by using seed-based functional connectivity (FC) analysis and gray matter volume (GMV) measurement in schizophrenia patients with AVH during 1 Hz rTMS treatment. Although low-frequency rTMS treatment did not affect the volumetric changes of NAcc, the abnormal FC patterns of NAcc, including increased FC of NAcc with the temporal lobes and decreased FC of NAcc with the frontal cortices in the pretreatment patients compared to healthy controls, were normalized or reversed after treatment. These FC changes were associated with improvements in clinical symptoms and neurocognitive functions. Our findings may extend our understanding of the NAcc in the pathology of schizophrenia with AVH and might be a biomarker of clinical effect for low-frequency rTMS treatment in schizophrenia.

Repetitive transcranial magnetic stimulation and transcranial direct current stimulation for auditory hallucinations in schizophrenia: Systematic review and meta-analysis

Through imaging studies, a significant increase in cerebral activity has been detected in fronto-temporal areas in patients experiencing auditory verbal hallucinations. Therefore, non-invasive neuromodulation, in particular transcranial direct current stimulation (tDCS) and repetitive transcranial magnetic stimulation (rTMS), has been considered as a therapeutic intervention for medication-resistant auditory verbal hallucinations in schizophrenia. We aimed to synthesize results from randomized trials on either rTMS or tDCS versus placebo in patients with schizophrenia by including five recently published trials in the field. A systematic review and meta-analysis of relevant literature was conducted. Studies were included on the basis of pre-defined selection criteria. The quality of the studies was assessed by the Cochrane Risk of Bias Tool for Randomized Controlled Trials. RevMan 5.3 was used to conduct the statistical analysis. Including 465 and 960 patients, respectively, 12 tDCS and 27 rTMS studies were included. Regarding treatment of medication refractory auditory verbal hallucinations, no significant effect of tDCS (-0.23 [-0.49, 0.02], p = 0.08) or rTMS (-0.19 [-0.50, 0,11], p = 0.21) was found compared to sham in this meta-analysis. The current study found that it cannot be concluded that rTMS and tDCS are efficacious in treating medication-resistant auditory verbal hallucinations. Larger randomized controlled tDCS trials of a higher quality should be conducted in the future to establish substantial evidence of tDCS. The interventions appear safe and may have beneficial effects on other outcomes.

Transcranial Magnetic Stimulation for Positive Symptoms in Schizophrenia: A Systematic Review

Transcranial magnetic stimulation (TMS) has been proposed as a potential treatment add-on for positive symptoms in schizophrenia. To summarize the current evidence for its efficacy, we reviewed clinical trials from the last 20 years that investigated TMS for positive symptoms. We performed a search on the PubMed database for clinical trials that used TMS for the treatment of positive symptoms published in peer-reviewed journals. We excluded reviews, case reports, and opinion papers. Of the 30 studies included, the majority (n = 25) investigated auditory verbal hallucinations. Twelve studies found evidence for a positive treatment effect of TMS on positive symptoms, while 18 did not find enough evidence to conclude that TMS is effective for positive symptoms. However, the small sample size of the majority of studies is a limiting factor for the reliability of previous findings. In conclusion, evidence for an effect of TMS on positive symptoms was mixed. Since most of the studies were performed in patients with auditory verbal hallucinations, further research of TMS for other positive symptoms including thought disorder and delusions is warranted.

High frequency repetitive transcranial magnetic stimulation of dorsomedial prefrontal cortex for negative symptoms in patients with schizophrenia: A double-blind, randomized controlled trial

Negative symptoms are the major challenge in clinical management of schizophrenia. Dorsomedial prefrontal cortex (DMPFC) has been suggested to be highly involved in the mechanisms of negative symptoms of schizophrenia. However, the effect of repetitive Transcranial Magnetic Stimulation (rTMS) over DMPFC has not yet been well studied. In this double-blind, randomized controlled rTMS clinical trial, thirty-three participants (17 in active group and 16 in sham group) were enrolled. This study includes the rTMS treatment phase (lasts for 4 weeks) and a subsequently naturalistic follow-up phase (lasts for another 4 weeks). Schizophrenia patients with prominently negative symptoms were randomly assigned to receive 10 Hz or sham rTMS intervention. The score change in Scale of Negative Symptoms (SANS) was defined as the primary outcome measure. There was a significant decrease in negative symptoms, especially affective flattening and anhedonia in schizophrenia patients after DMPFC-rTMS intervention. Moreover, the negative symptoms improvement could maintain at least another 4 weeks. In addition, no memory impairment or serious adverse reaction of rTMS emerged. Our results suggest that high frequency rTMS over DMPF may represent a safe and effective treatment for negative symptoms in patients with schizophrenia.

Repetitive Transcranial Magnetic Stimulation as a Therapeutic and Probe in Schizophrenia: Examining the Role of Neuroimaging and Future Directions

Schizophrenia is a complex condition associated with perceptual disturbances, decreased motivation and affect, and disrupted cognition. Individuals living with schizophrenia may experience myriad poor outcomes, including impairment in independent living and function as well as decreased life expectancy. Though existing treatments may offer benefit, many individuals still experience treatment resistant and disabling symptoms. In light of the negative outcomes associated with schizophrenia and the limitations in currently available treatments, there is a significant need for novel therapeutic interventions. Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive brain stimulation technique that can modulate the activity of discrete cortical regions, allowing direct manipulation of local brain activation and indirect manipulation of the target's associated neural networks. rTMS has been studied in schizophrenia for the treatment of auditory hallucinations, negative symptoms, and cognitive deficits, with mixed results. The field's inability to arrive at a consensus on the use rTMS in schizophrenia has stemmed from a variety of issues, perhaps most notably the significant heterogeneity amongst existing trials. In addition, it is likely that factors specific to schizophrenia, rather than the rTMS itself, have presented barriers to the interpretation of existing results. However, advances in approaches to rTMS as a biologic probe and therapeutic, many of which include the integration of neuroimaging with rTMS, offer hope that this technology may still play a role in improving the understanding and treatment of schizophrenia.

Treatment effect variability in brain stimulation across psychiatric disorders: A meta-analysis of variance

Noninvasive brain stimulation methods such as transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) are promising add-on treatments for a number of psychiatric conditions. Yet, some of the initial excitement is wearing off. Randomized controlled trials (RCT) have found inconsistent results. This inconsistency is suspected to be the consequence of variation in treatment effects and solvable by identifying responders in RCTs and individualizing treatment. However, is there enough evidence from RCTs that patients respond differently to treatment? This question can be addressed by comparing the variability in the active stimulation group with the variability in the sham group. We searched MEDLINE/PubMed and included all double-blinded, sham-controlled RCTs and crossover trials that used TMS or tDCS in adults with a unipolar or bipolar depression, bipolar disorder, schizophrenia spectrum disorder, or obsessive compulsive disorder. In accordance with the PRISMA guidelines to ensure data quality and validity, we extracted a measure of variability of the primary outcome. A total of 130 studies with 5748 patients were considered in the analysis. We calculated variance-weighted variability ratios for each comparison of active stimulation vs sham and entered them into a random-effects model. We hypothesized that treatment effect variability in TMS or tDCS would be reflected by increased variability after active compared with sham stimulation, or in other words, a variability ratio greater than one. Across diagnoses, we found only a minimal increase in variability after active stimulation compared with sham that did not reach statistical significance (variability ratio = 1.03; 95% CI, 0.97, 1.08, P = 0.358). In conclusion, this study found little evidence for treatment effect variability in brain stimulation, suggesting that the need for personalized or stratified medicine is still an open question.

Repetitive transcranial magnetic stimulation (rTMS) for schizophrenia patients treated with clozapine

OBJECTIVES

Biological strategies to improve treatment efficacy in clozapine-treated patients are urgently needed. Repetitive transcranial magnetic stimulation (rTMS) merits consideration as intervention for patients with persistent auditory hallucinations (AH) or negative symptoms (NS) not responding sufficiently to clozapine treatment.

METHODS

Data from 10 international RCTs of rTMS for patients being treated with clozapine were pooled. Two levels of symptomatic response were defined: improvement of ≥20% and ≥50% on study-specific primary endpoint scales. Changes in the positive and negative syndrome scale (PANSS) from baseline to endpoint assessment were also analysed.

RESULTS

Analyses of 131 patients did not reveal a significant difference for ≥20% and ≥50% response thresholds for improvement of AH, negative or total symptoms between active and sham rTMS groups. The number needed to treat (NNT) for an improvement in persistent AH was nine following active rTMS. PANSS scores did not improve significantly from baseline to endpoint between active and sham groups in studies investigating NS and AH.

CONCLUSIONS

rTMS as a treatment for persistent symptoms in clozapine-treated patients did not show a beneficial effect of active compared to sham treatment. For AH, the size of the NNTs indicates a possible beneficial effect of rTMS.

Efficacy of repetitive transcranial magnetic stimulation on auditory hallucinations in schizophrenia: A meta-analysis

To evaluate the efficacy of repetitive transcranial magnetic stimulation (rTMS) on auditory hallucinations (AH) in schizophrenia, we conducted a meta-analysis of currently available randomized control studies (RCTs). Electronic databases were searched to identify relevant literatures. Only RCTs that met the inclusion criteria were enrolled for further analysis. Standard mean difference (SMD) and 95% confidence interval (CI) values were used to evaluate the effects of rTMS. The overall robustness of the results was assessed by analyzing the influence of single studies. Publication bias was analyzed using funnel plots. Eleven eligible studies were included in this meta-analysis. Auditory hallucinations improved more in the rTMS group than in the sham group (SMD = -0.27, 95%CI = -0.51 to -0.03). However, this result was not stable after sensitivity analysis. Despite a moderate effect for rTMS on AH, future definitive trials of rTMS with rigorous processes and high-quality reporting are needed.

Evidence-based guidelines on the therapeutic use of repetitive transcranial magnetic stimulation (rTMS): An update (2014-2018)

A group of European experts reappraised the guidelines on the therapeutic efficacy of repetitive transcranial magnetic stimulation (rTMS) previously published in 2014 [Lefaucheur et al., Clin Neurophysiol 2014;125:2150-206]. These updated recommendations take into account all rTMS publications, including data prior to 2014, as well as currently reviewed literature until the end of 2018. Level A evidence (definite efficacy) was reached for: high-frequency (HF) rTMS of the primary motor cortex (M1) contralateral to the painful side for neuropathic pain; HF-rTMS of the left dorsolateral prefrontal cortex (DLPFC) using a figure-of-8 or a H1-coil for depression; low-frequency (LF) rTMS of contralesional M1 for hand motor recovery in the post-acute stage of stroke. Level B evidence (probable efficacy) was reached for: HF-rTMS of the left M1 or DLPFC for improving quality of life or pain, respectively, in fibromyalgia; HF-rTMS of bilateral M1 regions or the left DLPFC for improving motor impairment or depression, respectively, in Parkinson's disease; HF-rTMS of ipsilesional M1 for promoting motor recovery at the post-acute stage of stroke; intermittent theta burst stimulation targeted to the leg motor cortex for lower limb spasticity in multiple sclerosis; HF-rTMS of the right DLPFC in posttraumatic stress disorder; LF-rTMS of the right inferior frontal gyrus in chronic post-stroke non-fluent aphasia; LF-rTMS of the right DLPFC in depression; and bihemispheric stimulation of the DLPFC combining right-sided LF-rTMS (or continuous theta burst stimulation) and left-sided HF-rTMS (or intermittent theta burst stimulation) in depression. Level A/B evidence is not reached concerning efficacy of rTMS in any other condition. The current recommendations are based on the differences reached in therapeutic efficacy of real vs. sham rTMS protocols, replicated in a sufficient number of independent studies. This does not mean that the benefit produced by rTMS inevitably reaches a level of clinical relevance.

[Procognitive effects of transcranial magnetic stimulation in the light of neurocognitive deficit in schizophrenia]

Transcranial magnetic stimulation (TMS) is a relatively new method of non-invasive therapy of mental and neurological diseases that has great potential of therapeutic and diagnostic application. In schizophrenia, TMS may exert a positive effect on cognitive deficit. However this issue remains open. The authors analyze recent studies focused on the dynamics of neurocognitive deficit in TMS therapy and consider clinical effects of TMS in schizophrenia. The analysis has shown that TMS is successfully implemented in treatment of auditory positive symptoms and studies on its effect on negative symptoms of schizophrenia are perspective. Procognitive effect was found in working memory domain, and partially in perception domain within the perception of faces and facial expressions. The data on regulative functions, attention, speech, and nondeclarative memory remains controversial. It has been concluded that further research is needed to clarify the place of TMS in schizophrenia therapy.

Efficacy and Safety of Intensive Transcranial Magnetic Stimulation

Repetitive transcranial magnetic stimulation (rTMS) is customarily applied on a daily basis for prolonged periods of time for the treatment of psychiatric diseases. The process is demanding in terms of staff and patient time, and the onset of the effect is slow. Recently, intensive rTMS protocols have been introduced in which stimulation is applied to the same area more than once a day with a higher than standard number of pulses. This article reviews 16 articles to determine the safety and efficacy of such protocols. Intensive rTMS seems to be effective in various mental disorders. It appears to have, in general, the same adverse events as classic, long-term, daily rTMS, and it is largely well tolerated by the patients. One episode of depersonalization, one of increased suicidal thoughts, and two of induced mania were observed in the 16 studies reviewed. The advantages of intensive rTMS are in the possible acute effect of the stimulation and in the possible reduction in the time required to achieve remission in depression (and potentially other disorders). It remains uncertain whether intensive rTMS is more effective than sham stimulation or once-daily, long-term rTMS.

Auditory verbal hallucinations in schizophrenia: current perspectives in brain stimulation treatments

PURPOSE

This review reports the current perspectives of brain stimulation techniques in the treatment of auditory verbal hallucinations (AVH) in schizophrenia.

METHODS

A systematic search of the literature in the PubMed database revealed that the most studied techniques are noninvasive techniques (NIBS), including electroconvulsive therapy (ECT), transcranial direct current stimulation (tDCS) and repetitive transcranial magnetic stimulation (rTMS).

RESULTS

The results showed that ECT could have great clinical efficacy but is currently underused in practice perhaps due to the costs associated with its limited implementation and potential associated risks. tDCS is still poorly studied and does not demonstrate sufficiently homogeneous or conclusive results yet to prove its efficacy in the treatment of AVH. However, its safe and simple implementation allows us to recommend it to patients who are refractory to other stimulation techniques. Finally, rTMS seems to be the most efficacious NIBS to offer patients with persistent AVH as an add-on therapeutic strategy. Its implementation has a non negligible cost but can be performed by a single practitioner. Great evolution in these techniques with technological progress, robotics and computer science are currently being tested and will undoubtedly improve the clinical efficacy of these procedures, particularly towards more personalized treatments such as individual rTMS targets and intensities. There are also new techniques for deep brain stimulation based on focused ultrasound that could provide much insight into the treatment of AVH in schizophrenia.

CONCLUSION

This review suggests that add-on brain stimulation treatments could play a key role among the therapeutic strategies for auditory hallucinations reduction in schizophrenia.

Treating auditory hallucinations with transcranial direct current stimulation in a double-blind, randomized trial

OBJECTIVE

Transcranial direct current stimulation (tDCS) could be a treatment option for medication-resistant auditory hallucinations (AH), but so far results have been inconclusive, and large sample trials have been missing. This study used tDCS as a treatment method for these hallucinations in a double-blind, placebo-controlled study with a relatively large sample size.

METHODS

Fifty-four patients of several diagnostic categories with medication-resistant AH were randomized and treated during 10 sessions of 20 min each, with either 2 mA tDCS or placebo, administered on five consecutive days (i.e., two sessions per day). Anodal stimulation was targeted at the left dorsolateral prefrontal cortex, cathodal stimulation at the left temporoparietal junction. AH severity was assessed using the Auditory Hallucination Rating Scale (AHRS). Other outcome measures were assessed with the Positive and Negative Syndrome Scale (PANSS), the Stroop, and the Trail Making Test.

RESULTS

AH frequency and severity decreased significantly over time, as did the scores on the total and general subscales of the PANSS. However, there was no significant interaction effect with the treatment group on any of the main outcome measures.

CONCLUSIONS

We found no evidence that tDCS is more effective for medication-resistant AH than placebo, even though AH frequency and severity decreased in both groups. An alternative strategy may be to offer tDCS at an earlier stage of illness. In the light of recent investigations into the neurophysiological mechanisms behind tDCS, we may also have to consider the possibility that tDCS is not able to induce any long-lasting brain changes.

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

Auditory verbal hallucinations (AH) are core symptoms of schizophrenia. They are often severely distressing and refractory to therapy. Their perception is associated with increased activity in temporoparietal areas of the brain. Repetitive transcranial magnetic stimulation (rTMS) can reduce focal brain hyperactivity and has been shown to ameliorate AH. However, controlled multicenter clinical trials are still missing, effect sizes are moderate, and the treatment with rTMS is time consuming. Continuous theta burst stimulation (cTBS) is a quicker and potentially more effective technique to reduce cortical hyperactivity. First case and pilot studies indicate effectiveness in the treatment of AH. In this randomized, sham-controlled, double-blind multicenter clinical trial, 86 patients with schizophrenia spectrum disorder will be randomized to either cTBS or sham to the left and right temporoparietal cortex during three consecutive weeks (15 sessions totally). In each session, both hemispheres will be stimulated sequentially. The order in the first session (left-right or right-left, respectively) will be determined by randomization and alternated in all following sessions. Primary outcome is the reduction of mean PSYRATS-AH score after cTBS as compared to sham treatment. Follow-up measurements will be performed 1, 3 and 6 months after the end of the treatment. Statistical analysis will be based on the intention-to-treat population including all randomized patients using an analysis of covariance. This multicenter-controlled clinical trial will be able to provide decisive evidence for the efficacy of cTBS in the treatment of AH. The results will be suitable to clarify the role of this innovative, pathophysiology-based therapeutic approach in treatment guidelines for AH.

TRIAL REGISTRY

ClinicalTrials.gov identifier: NCT02670291.

Non-invasive brain stimulation for negative symptoms in schizophrenia: An updated systematic review and meta-analysis

BACKGROUND

Schizophrenia is a mental disorder with significant socioeconomic burden. Although current pharmacological treatments are effective for treating positive symptoms, medications have little-to-no effect in the treatment of negative symptoms.

OBJECTIVE

To assess the efficacy of non-invasive brain stimulation (NIBS) for negative symptoms in schizophrenia in randomized clinical trials (RCTs).

METHODS

A systematic review in Medline and Cochrane Library databases was performed up to May 31, 2017. The primary outcome was Hedges' g for continuous scores in a random-effects model. Heterogeneity was evaluated with the I² and χ² tests. Publication bias was assessed using Begg's funnel plot.

RESULTS

31 RCTs (n = 1272) were included, most with small-to-modest sample sizes. Both repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) were superior to sham (Hedges' g = 0.19; 95% CI 0.07-0.32; and 0.5; 0.02-0.97, respectively). Only one study evaluated the use of transcutaneous auricular vagus nerve stimulation (taVNS). The funnel plot and Eggers test showed that the risk of publication bias was low. In relation to heterogeneity, we found an I² of 0% (p = 0.749) and 51.3% (0.055) for rTMS and tDCS, respectively.

CONCLUSION

Both rTMS and tDCS were superior to sham stimulation for ameliorating negative symptoms in schizophrenia. We found no considerable heterogeneity or publication bias in our analysis, corroborating the strength of our findings. Not enough studies on other NIBS techniques, such as taVNS, were found for an isolated analysis. Further RCTs with larger sample sizes are needed to clarify the specific impact of NIBS on negative symptoms in schizophrenia.

Effects of low frequency rTMS treatment on brain networks for inner speech in patients with schizophrenia and auditory verbal hallucinations

INTRODUCTION

Efficacy of repetitive Transcranial Magnetic Stimulation (rTMS) targeting the temporo-parietal junction (TPJ) for the treatment of auditory verbal hallucinations (AVH) remains under debate. We assessed the influence of a 1Hz rTMS treatment on neural networks involved in a cognitive mechanism proposed to subserve AVH.

METHODS

Patients with schizophrenia (N=24) experiencing medication-resistant AVH completed a 10-day 1Hz rTMS treatment. Participants were randomized to active stimulation of the left or bilateral TPJ, or sham stimulation. The effects of rTMS on neural networks were investigated with an inner speech task during fMRI. Changes within and between neural networks were analyzed using Independent Component Analysis.

RESULTS

rTMS of the left and bilateral TPJ areas resulted in a weaker network contribution of the left supramarginal gyrus to the bilateral fronto-temporal network. Left-sided rTMS resulted in stronger network contributions of the right superior temporal gyrus to the auditory-sensorimotor network, right inferior gyrus to the left fronto-parietal network, and left middle frontal gyrus to the default mode network. Bilateral rTMS was associated with a predominant inhibitory effect on network contribution. Sham stimulation showed different patterns of change compared to active rTMS.

CONCLUSION

rTMS of the left temporo-parietal region decreased the contribution of the left supramarginal gyrus to the bilateral fronto-temporal network, which may reduce the likelihood of speech intrusions. On the other hand, left rTMS appeared to increase the contribution of functionally connected regions involved in perception, cognitive control and self-referential processing. These findings hint to potential neural mechanisms underlying rTMS for hallucinations but need corroboration in larger samples.

Repetitive transcranial magnetic stimulation for treating the symptoms of schizophrenia: A PRISMA compliant meta-analysis

OBJECTIVE

To explore the efficacies of 1-Hz (low frequency) and 10-Hz (high frequency) repetitive transcranial magnetic stimulation (rTMS) in treating auditory hallucinations and negative symptoms of schizophrenia, respectively.

METHODS

Electronic databases were searched to identify relevant literature. Standard mean difference (SMD) and 95% confidence interval (CI) values were used to evaluate the effects of rTMS. The stability and sensitivity of the results, the source of heterogeneity, and the recommended grade of the evidence were also analyzed.

RESULTS

Thirteen studies of 1-Hz rTMS were included. The auditory hallucinations improved more in the rTMS group than in the sham group (SMD=-0.29, 95%CI=-0.57 to -0.01). However, this result was not stable after sensitivity analysis, and publication bias had a substantial impact on the results. Meta-analysis performed for seven studies of 10-Hz rTMS found that improvement of negative symptoms did not differ significantly between the real rTMS and sham groups. Finally, the grade of evidence for this meta-analysis was found to be low.

CONCLUSION

Although there may appear to be a therapeutic effect for 1-Hz rTMS on auditory hallucinations of schizophrenia, this needs to be confirmed by large-scale randomized controlled trials before this finding can be recommended in clinical practice.

SIGNIFICANCE

1-Hz rTMS might have an effect on auditory hallucinations of schizophrenia.

Exercise Intensity-Dependent Effects on Cognitive Control Function during and after Acute Treadmill Running in Young Healthy Adults

The idea that physical activity differentially impacts upon performance of various cognitive tasks has recently gained increased interest. However, our current knowledge about how cognition is altered by acute physical activity is incomplete. To measure how different intensity levels of physical activity affect cognition during and after 1 bout of physical activity, 30 healthy, young participants were randomized to perform a not-X continuous performance test (CPT) during low (LI)- and moderate intensity (MI) running. The same participants were subsequently randomized to perform the not-X CPT post LI, MI, and high intensity (HI) running. In addition, exercise related mood changes were assessed through a self-report measure pre and post running at LI, MI, and HI. Results showed worsening of performance accuracy on the not-X CPT during one bout of moderate compared to low intensity running. Post running, there was a linear decrease in reaction time with increasing running intensity and no change in accuracy or mood. The decreased reaction times post HI running recovered back to baseline within 20 min. We conclude that accuracy is acutely deteriorated during the most straining physical activity while a transient intensity-dependent enhancement of cognitive control function is present following physical activity.

Active and placebo transcranial magnetic stimulation effects on external and internal auditory hallucinations of schizophrenia

OBJECTIVE

Repetitive transcranial magnetic stimulation (rTMS) over the left temporo-parietal region has been proposed as a treatment for resistant auditory verbal hallucinations (AVH), but which patients are more likely to benefit from rTMS is still unclear. This study sought to assess the effects of rTMS on AVH, with a focus on hallucination phenomenology.

METHOD

Twenty-seven patients with schizophrenia and medication-resistant AVH participated to a randomized, double-blind, placebo-controlled, add-on rTMS study. The stimulation targeted a language-perception area individually determined using functional magnetic resonance imaging and a language recognition task. AVH were assessed using the hallucination subscale of the Scale for the Assessment of Positive Symptoms (SAPS). The spatial location of AVH was assessed using the Psychotic Symptom Rating Scales.

RESULTS

A significant improvement in SAPS hallucination subscale score was observed in both actively treated and placebo-treated groups with no difference between both modalities. Patients with external AVH were significantly more improved than patients with internal AVH, with both modalities.

CONCLUSIONS

A marked placebo effect of rTMS was observed in patients with resistant AVH. Patients with prominent external AVH may be more likely to benefit from both active and placebo interventions. Cortical effects related to non-magnetic stimulation of the auditory cortex are suggested.

Placebo Response in Repetitive Transcranial Magnetic Stimulation Trials of Treatment of Auditory Hallucinations in Schizophrenia: A Meta-Analysis

Several meta-analyses have assessed the response of patients with schizophrenia with auditory verbal hallucinations (AVH) to treatment with repetitive transcranial magnetic stimulation (rTMS); however, the placebo response has never been explored. Typically observed in a therapeutic trial, the placebo effect may have a major influence on the effectiveness of rTMS. The purpose of this meta-analysis is to evaluate the magnitude of the placebo effect observed in controlled studies of rTMS treatment of AVH, and to determine factors that can impact the magnitude of this placebo effect, such as study design considerations and the type of sham used.The study included twenty-one articles concerning 303 patients treated by sham rTMS. A meta-analytic method was applied to obtain a combined, weighted effect size, Hedges's g. The mean weighted effect size of the placebo effect across these 21 studies was 0.29 (P < .001). Comparison of the parallel and crossover studies revealed distinct results for each study design; placebo has a significant effect size in the 13 parallel studies (g = 0.44, P < 10(-4)), but not in the 8 crossover studies (g = 0.06, P = .52). In meta-analysis of the 13 parallel studies, the 45° position coil showed the highest effect size. Our results demonstrate that placebo effect should be considered a major source of bias in the assessment of rTMS efficacy. These results fundamentally inform the design of further controlled studies, particularly with respect to studies of rTMS treatment in psychiatry.

Theta Burst Transcranial Magnetic Stimulation for Auditory Verbal Hallucinations: Negative Findings From a Double-Blind-Randomized Trial

BACKGROUND

Auditory verbal hallucinations (AVH) in schizophrenia are resistant to antipsychotic medication in approximately 25% of patients. Treatment with repetitive transcranial magnetic stimulation (rTMS) for refractory AVH has shown varying results. A stimulation protocol using continuous theta burst rTMS (TB-rTMS) showed high efficacy in open label studies. We tested TB-rTMS as a treatment strategy for refractory AVH in a double-blind, placebo-controlled trial.

METHODS

Seventy-one patients with AVH were randomly allocated to TB-rTMS or placebo treatment. They received 10 TB-rTMS or sham treatments over the left temporoparietal cortex in consecutive days. AVH severity was assessed at baseline, end of treatment and follow-up using the Psychotic Symptom Rating Scale (PSYRATS) and the Auditory Hallucinations Rating Scale (AHRS). Other schizophrenia-related symptoms were assessed with the Positive and Negative Syndrome Scale (PANSS).

RESULTS

Seven patients dropped out before completing the study. In the remaining 64, AVH improved significantly after treatment in both groups as measured with both PSYRATS and AHRS. PANSS positive and general subscores also decreased, but the negative subscores did not. However, improvement did not differ significantly between the TB-rTMS and the placebo group on any outcome measure.

CONCLUSIONS

Symptom reduction could be achieved in patients with medication-resistant hallucinations, even within 1 week time. However, as both groups showed similar improvement, effects were general (ie, placebo-effects) rather than specific to treatment with continuous TB-rTMS. Our findings highlight the importance of double-blind trials including a sham-control condition to assess efficacy of new treatments such as TMS.

Noninvasive brain stimulation for the treatment of auditory verbal hallucinations in schizophrenia: methods, effects and challenges

This mini-review focuses on noninvasive brain stimulation techniques as an augmentation method for the treatment of persistent auditory verbal hallucinations (AVH) in patients with schizophrenia. Paradigmatically, we place emphasis on transcranial magnetic stimulation (TMS). We specifically discuss rationales of stimulation and consider methodological questions together with issues of phenotypic diversity in individuals with drug-refractory and persistent AVH. Eventually, we provide a brief outlook for future investigations and treatment directions. Taken together, current evidence suggests TMS as a promising method in the treatment of AVH. Low-frequency stimulation of the superior temporal cortex (STC) may reduce symptom severity and frequency. Yet clinical effects are of relatively short duration and effect sizes appear to decrease over time along with publication of larger trials. Apart from considering other innovative stimulation techniques, such as transcranial Direct Current Stimulation (tDCS), and optimizing stimulation protocols, treatment of AVH using noninvasive brain stimulation will essentially rely on accurate identification of potential responders and non-responders for these treatment modalities. In this regard, future studies will need to consider distinct phenotypic presentations of AVH in patients with schizophrenia, together with the putative functional neurocircuitry underlying these phenotypes.

Neuromodulation Treatments for Schizophrenia

Schizophrenia is a psychiatric disorder that causes great suffering and debilitation worldwide. We have a multitude of medications that are effective for psychosis. However, these have not been successful in treating the negative and cognitive symptom domains of schizophrenia. These symptoms are responsible for the larger part of functional impairments that result from schizophrenia. In addition, there are many patients for whom no significant improvement is achieved even in the positive symptom domain. Hence, other treatment modalities have been explored to help these patients. Electroconvulsive therapy and transcranial magnetic stimulation are two of the most promising adjunct treatment methods for medication resistant schizophrenia. Electroconvulsive therapy is the gold standard treatment for catatonias whether associated with schizophrenia, mood disorders or other non-psychiatric disorders. Although not effective for negative symptoms, electroconvulsive therapy provides substantial augmentation to antipsychotic medications in improving positive symptoms and overall severity. Electroconvulsive therapy should be considered more often in patients with inadequate response to antipsychotic medications even when they do not have prominent affective symptoms. Transcranial magnetic stimulation has emerged as a promising useful therapeutic tool in targeting medication resistant auditory hallucinations and negative symptoms. Transcranial magnetic stimulation has proven to be very safe and well-tolerated by the patients in spite of its labor intensiveness. The incorporation of transcranial magnetic stimulation to routine clinical use awaits further studies to substantiate its efficacy and to optimize and customize treatment parameters to individual patients and their symptom patterns. Moreover, combining transcranial magnetic stimulation with electroconvulsive therapy to synergize their likely different mechanisms of action is another exciting possibility.

Transcranial magnetic stimulation, transcranial direct current stimulation and electroconvulsive therapy for medication-resistant psychosis of schizophrenia

PURPOSE OF REVIEW

Despite adequate antipsychotic treatment, 20-30% of patients with schizophrenia fail to obtain remission from psychosis. Physical stimulation treatments may provide an alternative therapy. In this review, we summarize the most recent studies regarding repetitive transcranial magnetic stimulation (rTMS), transcranial direct current stimulation (tDCS) and electroconvulsive therapy (ECT) for medication-resistant psychosis in schizophrenia.

RECENT FINDINGS

Stimulation techniques in the treatment of medication-resistant psychosis have shown inconsistent results. Initial results of rTMS for auditory verbal hallucinations (AVH) were promising, but three recent large randomized controlled trials (RCTs) show similar results of rTMS as placebo. tDCS has shown initial promise as a treatment for AVH, but only in case studies and in two small RCTs. Larger studies are needed to define its efficacy. Although psychotic symptoms generally decrease after ECT, its efficacy has not been demonstrated in comparison with placebo.

SUMMARY

Although previous meta-analyses indicate significant mean effect sizes for rTMS for intractable AVH, three recent large RCTs indicate no effect compared with placebo. The use of tDCS for resistant AVH and ECT for intractable psychosis has shown some initial promise, but adequately sized placebo-controlled RCTs are now needed. Taken together, the evidence for physical stimulation techniques to relieve medication-resistant psychosis is currently weak.