rTMS strategies for the study and treatment of schizophrenia: a review

Repetitive transcranial magnetic stimulation for psychiatric symptoms in long-term hospitalized veterans with schizophrenia: A randomized double-blind controlled trial

Multiple lines of evidence demonstrate that high-frequency (HF) repetitive transcranial magnetic stimulation (rTMS) may improve clinical outcomes in patients with schizophrenia (SCZ). However, the efficacy of HF-rTMS on psychiatric symptoms remains unknown in veterans with SCZ. This study aimed to investigate whether HF-rTMS was beneficial in alleviating the clinical symptoms in veterans with SCZ. Forty-seven long-term hospitalized veterans with SCZ were randomly allocated to receive neuronavigated 10 Hz rTMS or sham stimulation over the left dorsolateral prefrontal cortex once daily for four consecutive weeks. Symptoms were assessed by using the Positive and Negative Syndrome Scale at baseline and at the end of week 4. We also collected easily available routine biochemical markers including blood sugar, lipid profiles, hormone, and blood cell counts, considering that these markers may potentially be used to predict the outcomes of rTMS treatment. We found that there was a significant interaction effect of time and group on the positive symptoms. Compared with the sham group, the positive factor score of veterans with SCZ was significantly decreased after treatment in the real rTMS group. Interestingly, the improvement of positive symptoms from baseline to 4-week follow-up was significantly associated with the whole white blood cells (WBC) counts at baseline in the real rTMS group, and baseline WBC counts were predictive of the symptom improvement after rTMS treatment. Our findings indicate that add-on 10 Hz rTMS is beneficial for clinical symptoms in veterans with SCZ. In addition, the baseline WBC counts were predictive of the outcomes after treatment.

CLINICAL TRIAL REGISTRATION

clinicaltrials.gov, identifier NCT03774927.

The Effects of Repetitive Transcranial Magnetic Stimulation in Patients with Chronic Schizophrenia: Insights from EEG Microstates

The objective of this study was to investigate the effects of 10 Hz repetitive transcranial magnetic stimulation (rTMS) in patients with schizophrenia using EEG microstates. Thirty-eight patients with chronic schizophrenia were included in a double-blind, randomized and sham-controlled trial (19 participants in the active group and 19 participants in the sham group) and received 10 Hz active or sham rTMS stimulation to the left dorsolateral prefrontal cortex (left DLPFC) 5 days per week over for 4 weeks. Four classical microstate classes (i.e., classes A, B, C and D) were identified by clustering, and the parameters (i.e., duration, occurrence and contribution) of each class were computed. Our results showed that (1) after stimulation, the positive and negative syndrome scale (PANSS) positive scores decreased significantly in the active group; (2) the duration of the microstate of class C derived from EEG data decreased significantly in the active group; and (3) the change of the duration of class D in the active group was significantly higher than that in the sham group. Our findings demonstrated that 10 Hz active rTMS stimulation was beneficial to improving the positive symptoms of patients with chronic schizophrenia, and the EEG microstate could be an effective indicator of symptom improvements.

Effects of High-Frequency rTMS on Negative Symptoms and Cognitive Function in Hospitalized Patients With Chronic Schizophrenia: A Double-Blind, Sham-Controlled Pilot Trial

This study aimed to evaluate the efficacy of high-frequency repetitive transcranial magnetic stimulation (rTMS) over left dorsolateral pre-frontal cortex (DLPFC) in ameliorating negative symptoms and cognitive impairments in patients with chronic schizophrenia. Fifty-two patients with chronic schizophrenia were randomly assigned to two groups: active rTMS group and sham rTMS group, with existing antipsychotic drugs combined 20 sessions of 10 Hz active/sham rTMS over DLPFC (20 min/session, 5 times/week). The PANSS, RBANS, and SCWT were used to evaluate the clinical symptoms and cognitive functions of the patients. Our results indicated significant improvements in clinical symptoms (PANSS total and subscale scores) and cognitive functions (RBANS total and subscale scores, card 1 and card 3 of the SCWT test) (All p <0.05) after 4-week intervention both in active and sham rTMS group. Moreover, the active rTMS group showed more effective on ameliorating negative symptoms (p = 0.002), immediate memory (p = 0.016) and delayed memory (p = 0.047) compared to the sham group. Interestingly, PANSS negative symptom scores was negatively correlated with RBANS language scores in the real stimulation group (p = 0.046). The study found that the high frequency rTMS stimulation over left DLPFC as a supplement to antipsychotics may have potential benefits in improving clinical symptoms and cognitive functions in patients with chronic schizophrenia.

P300 Analysis Using High-Density EEG to Decipher Neural Response to rTMS in Patients With Schizophrenia and Auditory Verbal Hallucinations

Schizophrenia is a complex disorder about which much is still unknown. Potential treatments, such as transcranial magnetic stimulation (TMS), have not been exploited, in part because of the variability in behavioral response. This can be overcome with the use of response biomarkers. It has been however shown that repetitive transcranial magnetic stimulation (rTMS) can the relieve positive and negative symptoms of schizophrenia, particularly auditory verbal hallucinations (AVH). This exploratory work aims to establish a quantitative methodological tool, based on high-density electroencephalogram (HD-EEG) data analysis, to assess the effect of rTMS on patients with schizophrenia and AVH. Ten schizophrenia patients with drug-resistant AVH were divided into two groups: the treatment group (TG) received 1 Hz rTMS treatment during 10 daily sessions (900 pulses/session) over the left T3-P3 International 10-20 location. The control group (CG) received rTMS treatment over the Cz (vertex) EEG location. We used the P300 oddball auditory paradigm, known for its reduced amplitude in schizophrenia with AVH, and recorded high-density electroencephalography (HD-EEG, 256 channels), twice for each patient: pre-rTMS and 1 week post-rTMS treatment. The use of HD-EEG enabled the analysis of the data in the time domain, but also in the frequency and source-space connectivity domains. The HD-EEG data were linked with the clinical outcome derived from the auditory hallucinations subscale (AHS) of the Psychotic Symptom Rating Scale (PSYRATS), the Quality of Life Scale (QoLS), and the Depression, Anxiety and Stress Scale (DASS). The general results show a variability between subjects, independent of the group they belong to. The time domain showed a higher N1-P3 amplitude post-rTMS, the frequency domain a higher power spectral density (PSD) in the alpha and beta bands, and the connectivity analysis revealed a higher brain network integration (quantified using the participation coefficient) in the beta band. Despite the small number of subjects and the high variability of the results, this work shows a robust data analysis and an interplay between morphology, spectral, and connectivity data. The identification of a trend post-rTMS for each domain in our results is a first step toward the definition of quantitative neurophysiological parameters to assess rTMS treatment.

Efficacy of Intensive Cerebellar Intermittent Theta Burst Stimulation (iCiTBS) in Treatment-Resistant Schizophrenia: a Randomized Placebo-Controlled Study

Trans-cranial magnetic stimulation (TMS) can noninvasively modulate specific brain regions to dissipate symptoms in treatment-resistant schizophrenia (TRS). Citing impaired resting state connectivity between cerebellum and prefrontal cortex in schizophrenia, we aimed to study the effect of intermittent theta burst stimulation (iTBS) targeting midline cerebellum in TRS subjects on a randomized rater blinded placebo control study design. In this study, 36 patients were randomly allocated (using block randomization method) to active and sham iTBS groups. They were scheduled to receive ten iTBS sessions, two per day (total of 1200 pulses) for 5 days in a week. The Positive and Negative Syndrome Scale (PANSS), Brief Psychiatric Rating Scale (BPRS), Schizophrenia Cognition Rating Scale (SCoRS), Simpson-Angus Extrapyramidal Side Effects Scale (SAS), and Clinical Global Impression (CGI) were assessed at baseline, after last session, and at 2 weeks post-rTMS. Thirty patients (16 and 14 in active and sham groups) completed the study. Intention to treat analysis (ITT) using mixed (growth curve) model analysis was conducted. No significant group (active vs sham) × time (pretreatment–end of 10th session–end of 2 weeks post iTBS) interaction was found for any of the variable. No major side effects were reported. Our study fails to show a significant effect of intensive cerebellar iTBS (iCiTBS) on schizophrenia psychopathology, cognitive functions, and global improvement, compared with sham stimulation, in treatment resistant cases. However, we conclude that it is safe and well tolerated. Trials using better localization technique with large sample, longer duration, and better dosing protocols are needed.

Assessing the Effects of Continuous Theta Burst Stimulation Over the Dorsolateral Prefrontal Cortex on Human Cognition: A Systematic Review

Theta burst stimulation is increasingly growing in popularity as a non-invasive method of moderating corticospinal networks. Theta burst stimulation uses gamma frequency trains applied at the rhythm of theta, thus, mimicking theta–gamma coupling involved in cognitive processes. The dorsolateral prefrontal cortex has been found to play a crucial role in numerous cognitive processes. Here, we include 25 studies for review to determine the cognitive effects of continuous theta burst stimulation over the dorsolateral prefrontal cortex; 20 of these studies are healthy participant and five are patient (pharmacotherapy-resistant depression) studies. Due to the heterogeneous nature of the included studies, only a descriptive approach is used and meta-analytics ruled out. The cognitive effect is measured on various cognitive domains: attention, working memory, planning, language, decision making, executive function, and inhibitory and cognitive control. We conclude that continuous theta burst stimulation over the dorsolateral prefrontal cortex mainly inhibits cognitive performance. However, in some instances, it can lead to improved performance by inhibiting the effect of distractors or other competing irrelevant cognitive processes. To be precise, continuous theta burst stimulation over the right dorsolateral prefrontal cortex impaired attention, inhibitory control, planning, and goal-directed behavior in decision making but also improved decision making by reducing impulsivity. Conversely, continuous theta burst stimulation over the left dorsolateral prefrontal cortex impaired executive function, working, auditory feedback regulation, and cognitive control but accelerated the planning, decision-making process. These findings constitute a useful contribution to the literature on the cognitive effects of continuous theta burst stimulation over the dorsolateral prefrontal cortex.

[Positive changes in the severity of residual psychotic symptoms in schizophrenic patients switched to treatment with risperidone]

AIM

To evaluate the effect of changing therapy from typical antipsychotics to the atypical antipsychotic risperidone in the treatment of difficult-to-treat residual psychotic symptoms.

MATERIAL AND METHODS

The study included 15 patients, 8 men and 7 women, mean age 49.1±10.25 years, diagnosed with paranoid schizophrenia, partial remission (ICD-10 F20.04). At the beginning all participants received regular maintenance antipsychotic therapy with typical antipsychotics. The patient assessment with the PANSS, CGI scale and GAF scale was performed at the beginning (before the change of antipsychotics to risperidone) and in the end of the study. The primary efficacy endpoint was a reduction in scores on the PANSS items P1 'delusions' and P3 'hallucinatory behavior' to 1 (no such symptom) or 2 (minimal residual symptom). Secondary criteria were positive changes in the severity of other psychopathological symptoms and an increase in the social functioning level. The average dose of risperidone was 4.62±1.35 mg. The duration of treatment was 2 month.

RESULTS

After switching from typical antipsychotics to risperidone and two months monotherapy, there were significant positive changes in the total PANSS score as well as in positive subscale score and CGI-S score. The small, but statistically significant, changes were detected in the overall functioning of the patients (the increase in the GAF score). The dynamics of residual psychotic symptoms was unequal: the severity of hallucinatory symptoms decreased significantly while the delusional symptoms remained unchanged.

CONCLUSION

The authors suggest that excessive dopaminergic blockade might play a significant role in the pathogenesis of residual symptoms. This fact may explain the positive effect of treatment in the cases with the less degree of dopaminergic blockade. If it is true, the treatment strategy in the maintenance phase should not be a direct continuation of acute phase therapy and switching to other drugs and changing of the dose are needed.

Using human brain imaging studies as a guide toward animal models of schizophrenia

Schizophrenia is a heterogeneous and poorly understood mental disorder that is presently defined solely by its behavioral symptoms. Advances in genetic, epidemiological and brain imaging techniques in the past half century, however, have significantly advanced our understanding of the underlying biology of the disorder. In spite of these advances clinical research remains limited in its power to establish the causal relationships that link etiology with pathophysiology and symptoms. In this context, animal models provide an important tool for causally testing hypotheses about biological processes postulated to be disrupted in the disorder. While animal models can exploit a variety of entry points toward the study of schizophrenia, here we describe an approach that seeks to closely approximate functional alterations observed with brain imaging techniques in patients. By modeling these intermediate pathophysiological alterations in animals, this approach offers an opportunity to (1) tightly link a single functional brain abnormality with its behavioral consequences, and (2) to determine whether a single pathophysiology can causally produce alterations in other brain areas that have been described in patients. In this review we first summarize a selection of well-replicated biological abnormalities described in the schizophrenia literature. We then provide examples of animal models that were studied in the context of patient imaging findings describing enhanced striatal dopamine D2 receptor function, alterations in thalamo-prefrontal circuit function, and metabolic hyperfunction of the hippocampus. Lastly, we discuss the implications of findings from these animal models for our present understanding of schizophrenia, and consider key unanswered questions for future research in animal models and human patients.

rTMS in the treatment of drug addiction: an update about human studies

Drug addiction can be a devastating and chronic relapsing disorder with social, psychological, and physical consequences, and more effective treatment options are needed. Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive brain stimulation technique that has been assessed in a growing number of studies for its therapeutic potential in treating addiction. This review paper offers an overview on the current state of clinical research in treating drug addiction with rTMS. Because of the limited research in this area, all studies (including case reports) that evaluated the therapeutic use of rTMS in nicotine, alcohol, or illicit drug addiction were included in this review. Papers published prior to December 2012 were found through an NCBI PubMed search. A total of eleven studies were identified that met review criteria. There is nascent evidence that rTMS could be effective in reducing cocaine craving and nicotine and alcohol craving and consumption and might represent a potential therapeutic tool for treating addiction. Further studies are needed to identify the optimal parameters of stimulation for the most effective treatment of drug addiction, to improve our comprehension of the treatment neurophysiological effects, and to conduct rigorous, controlled efficacy studies with adequate power.

Practitioner review: schizophrenia spectrum disorders and the at-risk mental state for psychosis in children and adolescents--evidence-based management approaches

BACKGROUND

Schizophrenia spectrum disorders are severe mental illnesses which often result in significant distress and disability. Attempts have been made to prospectively identify and treat young people viewed as at high risk of impending nonaffective psychosis. Once a schizophrenia spectrum disorder has developed, prompt identification and management is required.

METHODS

This article reviews the literature relating to the assessment and management of 'at-risk mental states' (ARMS) and the treatment of schizophrenia spectrum disorders in children and adolescents. A systematic search of the literature was undertaken using EMBASE, MEDLINE, PsycINFO databases for the period January 1970-December 2012.

RESULTS

Evidence suggests that young people fulfilling the ARMS criteria are at high risk of adverse mental health outcomes but that the majority do not develop nonaffective psychosis over the medium term. Although clinical trial findings have been inconsistent, psychosocial approaches, such as cognitive behaviour therapy, may reduce the risk of transition to psychosis and improve some symptoms, at least over the short term. The effectiveness of psychotropic medication for the ARMS is uncertain although there is accumulating evidence for potential adverse effects of antipsychotic medication, even at low dose, in this population. For the schizophrenias, clinical trial findings suggest that, as in adults, antipsychotics should be selected on the basis of side-effect profile although clozapine may be helpful in treatment refractory illness. There are almost no studies of psychosocial treatments for schizophrenia in young people under 18, and some caution must be exercised when extrapolating the findings of adult studies to younger individuals.

CONCLUSIONS

A stepped care approach to the ARMS in young people represents a plausible potential management approach for those at high risk of serious mental health problems. However, predictive models currently lack precision and should focus on accurately identifying those at high risk for a variety of poor outcomes who may benefit most from intervention. There is also an urgent need for age-specific research in the area of psychosocial treatments for children and adolescents with schizophrenia.

Treatments in context: transcranial direct current brain stimulation as a potential treatment in pediatric psychosis

Childhood-onset schizophrenia is a chronic, severe form of schizophrenia, and is typically treatment resistant. Even after optimized pharmacotherapy, a majority (over 70%) of these pediatric patients present lasting psychotic symptoms and impaired cognition, necessitating the need for novel treatment modalities. Recent work in transcranial magnetic stimulation suggests moderate efficacy in symptom reduction in adult patients with schizophrenia; however, the transcranial magnetic stimulation treatment is cumbersome for this severely ill population. Transcranial direct current stimulation may provide a safe and effective adjuvant treatment for continued residual symptoms of schizophrenia.

Deep transcranial magnetic stimulation as a treatment for psychiatric disorders: a comprehensive review

Deep transcranial magnetic stimulation (TMS) is a technique of neuromodulation and neurostimulation based on the principle of electromagnetic induction of an electric field in the brain. The coil (H-coil) used in deep TMS is able to modulate cortical excitability up to a maximum depth of 6 cm and is therefore able not only to modulate the activity of the cerebral cortex but also the activity of deeper neural circuits. Deep TMS is largely used for the treatment of drug-resistant major depressive disorder (MDD) and is being tested to treat a very wide range of neurological, psychiatric and medical conditions. The aim of this review is to illustrate the biophysical principles of deep TMS, to explain the pathophysiological basis for its utilization in each psychiatric disorder (major depression, autism, bipolar depression, auditory hallucinations, negative symptoms of schizophrenia), to summarize the results presented thus far in the international scientific literature regarding the use of deep TMS in psychiatry, its side effects and its effects on cognitive functions.

Adjunctive treatment of bimodal repetitive transcranial magnetic stimulation (rTMS) in pharmacologically non-responsive patients with schizophrenia: a preliminary study

OBJECTIVES

We evaluated the efficacy of bimodal repetitive transcranial magnetic stimulation (rTMS) in treating pharmacologically non-responsive patients with schizophrenia.

METHODS

Ten patients with DSM-IV schizophrenia, unresponsive to pharmacological treatment, underwent treatment with 15 rTMS sessions, as an adjunctive therapy, for three weeks. Each session comprised 40 trains, beginning every 30s: 20 trains of 10 Hz rTMS to the left dorsolateral prefrontal cortex (DLPFC) with a 3-s duration and 20 trains of 1 Hz rTMS to the left temporoparietal cortex (TPC) with a 30-s duration. We assessed patients via the Positive and Negative Syndrome Scale (PANSS) and Korean Version of the Calgary Depression Scale for Schizophrenia (K-CDSS), at five time points: baseline, Days 8, 15, and 22, and 1 week after final treatment (Day 29). Patients who agreed to take neurocognitive tests underwent neurocognitive function evaluations at baseline and 1 week after final treatment.

RESULTS

At Day 29, all PANSS subscale scores in had decreased significantly compared to baseline (Z=-2.214, p=0.027, positive; Z=-2.132, p=0.033, negative; Z=-2.023, p=0.043, general pathology; Z=-2.371, p=0.018, total). Effect over time was significant for the PANSS positive and negative subscale scores and total score (χ(2)=13.35, p=0.010; χ(2)=10.27, p=0.036; and χ(2)=16.50, p=0.002, respectively) but not for the general pathology subscale. Among the neurocognitive tests, the fourth and fifth trials and total K-AVLT scores showed significant increases (Z=-2.041, p=0.041; Z=-2.251, p=0.024; and Z=-2.201, p=0.028, respectively), suggesting improvement in short-term auditory verbal memory.

CONCLUSIONS

Bimodal rTMS stimulation of left DLPFC and left TPC induced clinical improvement in pharmacologically non-responsive schizophrenia patients and may have improved their short-term verbal memories.

Deep transcranial magnetic stimulation add-on for treatment of negative symptoms and cognitive deficits of schizophrenia: a feasibility study

Treatment for negative symptoms and cognitive deficits, core elements of schizophrenia, remains inadequate. Stimulation of the prefrontal cortex via transcranial magnetic stimulation (TMS) yields only moderate results, possibly due to limited stimulation depth. Deep-TMS enables deeper and wider stimulation than before. This preliminary study is the first to examine deep-TMS as a possible add-on treatment for negative symptoms and cognitive deficits of schizophrenia. The effect of 20 daily deep-TMS sessions (20 Hz, 120% motor threshold) over the prefrontal cortex of 15 patients indicated improvement in cognition and negative symptoms that was maintained at 2-wk post-treatment follow-up.

Transcranial magnetic stimulation: a neuroscientific probe of cortical function in schizophrenia

Transcranial magnetic stimulation (TMS) is a neuropsychiatric tool that can serve as a useful method to better understand the neurobiology of cognitive function, behavior, and emotional processing. The purpose of this article is to examine the utility of TMS as a means to measure neocortical function in neuropsychiatric disorders in general, and schizophrenia in particular, for the Cognitive Neuroscience Treatment Research to Improve Cognition in Schizophrenia initiative. When incorporating TMS paradigms in research studies, methodologic considerations include technical aspects of TMS, cohort selection and confounding factors, and subject safety. Available evidence suggests benefits of TMS alone or in combination with neurophysiologic and neuroimaging methods, including positron emission tomography, single photon emission computed tomography, magnetic resonance imaging, functional magnetic resonance imaging, functional near infrared spectroscopy, magnetoencephalography, and electroencephalography, to explore neocortical function. With the multiple TMS techniques including single-pulse, paired-pulse, paired associative stimulation, and repetitive TMS and theta burst stimulation, combined with neurophysiologic and neuroimaging methods, there exists a plethora of TMS experimental paradigms to modulate neocortical physiologic processes. Specifically, TMS can measure cortical excitability, intracortical inhibitory and excitatory mechanisms, and local and network cortical plasticity. Coupled with functional and electrophysiologic modalities, TMS can provide insight into the mechanisms underlying healthy neurodevelopment and aging, as well as neuropsychiatric pathology. Thus, TMS could be a useful tool in the Cognitive Neuroscience Treatment Research to Improve Cognition in Schizophrenia armamentarium of biomarker methods. Future investigations are warranted to optimize TMS methodologies for this purpose.

Harnessing neuroplasticity for clinical applications

Neuroplasticity can be defined as the ability of the nervous system to respond to intrinsic or extrinsic stimuli by reorganizing its structure, function and connections. Major advances in the understanding of neuroplasticity have to date yielded few established interventions. To advance the translation of neuroplasticity research towards clinical applications, the National Institutes of Health Blueprint for Neuroscience Research sponsored a workshop in 2009. Basic and clinical researchers in disciplines from central nervous system injury/stroke, mental/addictive disorders, paediatric/developmental disorders and neurodegeneration/ageing identified cardinal examples of neuroplasticity, underlying mechanisms, therapeutic implications and common denominators. Promising therapies that may enhance training-induced cognitive and motor learning, such as brain stimulation and neuropharmacological interventions, were identified, along with questions of how best to use this body of information to reduce human disability. Improved understanding of adaptive mechanisms at every level, from molecules to synapses, to networks, to behaviour, can be gained from iterative collaborations between basic and clinical researchers. Lessons can be gleaned from studying fields related to plasticity, such as development, critical periods, learning and response to disease. Improved means of assessing neuroplasticity in humans, including biomarkers for predicting and monitoring treatment response, are needed. Neuroplasticity occurs with many variations, in many forms, and in many contexts. However, common themes in plasticity that emerge across diverse central nervous system conditions include experience dependence, time sensitivity and the importance of motivation and attention. Integration of information across disciplines should enhance opportunities for the translation of neuroplasticity and circuit retraining research into effective clinical therapies.

Tolerability of transcranial direct current stimulation in childhood-onset schizophrenia

BACKGROUND

In recent years, transcranial direct current stimulation (tDCS) has been used to study and treat many neuropsychiatric conditions. However, information regarding its tolerability in the pediatric population is lacking.

OBJECTIVE

This study aims to investigate the tolerability aspects of tDCS in the childhood-onset schizophrenia (COS) population.

METHODS

Twelve participants with COS completed this inpatient study. Participants were assigned to one of two groups: bilateral anodal dorsolateral prefrontal cortex (DLPFC) stimulation (n = 8) or bilateral cathodal superior temporal gyrus (STG) stimulation (n = 5). Patients received either 2 mA of active treatment or sham treatment (with possibility of open active treatment) for 20 minutes, for a total of 10 sessions (2 weeks).

RESULTS

tDCS was well tolerated in the COS population with no serious adverse events occurring during the study.

CONCLUSIONS

This is the first study to demonstrate that a 20-minute duration of 2 mA of bilateral anodal and bilateral cathodal DC polarization to the DLPFC and STG was well tolerated in a pediatric population.

Treatment of early-onset schizophrenia

PURPOSE OF REVIEW

Treatment of children who develop schizophrenia in childhood and early adolescence presents unique considerations. There has been increasing attention to the importance of early intervention and whether treatment effects may be affected by brain development.

RECENT FINDINGS

Several recent trials support the use of antipsychotics for treatment of schizophrenia in children and adolescents. Clozapine shows greater efficacy in children and adolescents than it has in adults. A large-scale trial comparing a first-generation antipsychotic (molindone) with newer agents did not find significant differences in treatment response, although the newer antipsychotics were associated with more severe weight gain. Data regarding effects of antipsychotics on brain development in children and young adolescents with schizophrenia are sparse, although one report found no difference between effects of clozapine and olanzapine on cortical thickness.

SUMMARY

Although psychosocial interventions are an important adjunctive treatment, antipsychotic medications continue to be the mainstay of treatment. Careful monitoring of metabolic side effects and age-appropriate intervention is particularly important, as children and adolescents appear to be more likely to develop metabolic abnormalities such as pronounced weight gain, which may significantly impact adherence as well as lead to other health issues.

A sham-controlled trial of left and right temporal rTMS for the treatment of auditory hallucinations

BACKGROUND

Several studies have reported reduction of auditory hallucinations (AH) after repetitive transcranial magnetic stimulation (rTMS) to the left temporal cortex. This study explored the effects of rTMS to the left and right temporal cortex.

METHOD

Eighteen subjects with schizophrenia and frequent AH were enrolled in a double-blind, cross-over trial of 3 days of active rTMS to the left or right temporal cortex, or sham rTMS to the vertex (control condition), followed by an open treatment phase. The effects on AH were assessed by a blinded rater, using the Auditory Hallucination Rating Scale (AHRS).

RESULTS

During the double-blind phase, active temporal rTMS did not result in significantly greater improvement in hallucination scores than sham rTMS to the vertex, apart from a reduction in distress scores. Hallucination scores improved during the open continued treatment phase.

CONCLUSIONS

This study did not demonstrate an advantage for left temporal rTMS compared to right temporal and sham stimulation, over a 3-day stimulation period, but found modest improvement in hallucinations during continued open label treatment.

Repetitive transcranial magnetic stimulation for refractory symptoms in schizophrenia

PURPOSE OF REVIEW

Schizophrenia is an illness associated with a substantial degree of treatment resistance and suboptimal therapeutic response. In recent years, novel brain stimulation technologies have been identified as potential treatments for schizophrenia and related disorders. Several published studies have assessed the use of repetitive transcranial magnetic stimulation (rTMS) in patients with schizophrenia.

RECENT FINDINGS

Most published studies have focused on the use of low-frequency rTMS to treat refractory auditory hallucinations. These studies support the efficacy of stimulation over the temporoparietal cortex. Several other studies have assessed high-frequency stimulation of the prefrontal cortex in the treatment of negative symptoms. Novel protocols to treat auditory hallucinations have been piloted and case reports are emerging on the use of maintenance rTMS to treat auditory hallucinations.

SUMMARY

Overall, rTMS studies have demonstrated some promise in the treatment of schizophrenia. However, more research is required to delineate the role of this technique in clinical practice and to explore novel stimulation techniques that may ultimately lead to improved therapeutic efficacy.

Brain stimulation in the study and treatment of addiction

Addiction is a devastating and chronically relapsing disorder. Repeated drug administration induces neuroadaptations associated with abnormal dopaminergic activity in the mesocorticolimbic circuitry, resulting in altered cortical neurotransmission and excitability. Electrical stimulation of specific brain regions can be used in animal models and humans to induce local activation or disruption of specific circuitries or alter neuronal excitability and cause neuroadaptations. Non-surgical stimulation of specific brain regions in human addicts can be achieved by transcranial magnetic stimulation (TMS). TMS is used for transient stimulation or disruption of neural activity in specific cortical regions, which can be used to assess cortical excitability, and to induce changes in cortical excitability. Moreover, it is suggested that repeated stimulation can cause long-lasting neuroadaptations. Therefore, TMS paradigms were used in some studies to assess the presence of altered cortical excitability associated with chronic drug consumption, while other studies have begun to assess the therapeutic potential of repetitive TMS. Similarly, transcranial direct current stimulation (tDCS) is used to modulate neuronal resting membrane potential in humans and alter cortical excitability. The current review describes how these brain stimulation techniques have recently been used for the study and treatment of addiction in animal models and humans.

Meta-analysis of the effects of repetitive transcranial magnetic stimulation (rTMS) on negative and positive symptoms in schizophrenia

BACKGROUND

A growing body of evidence suggests that repetitive transcranial magnetic stimulation (rTMS) can alleviate negative and positive symptoms of refractory schizophrenia. However, trials to date have been small and results are mixed.

METHODS

We performed meta-analyses of all prospective studies of the therapeutic application of rTMS in refractory schizophrenia assessing the effects of high-frequency rTMS to the left dorsolateral prefrontal cortex (DLPFC) to treat negative symptoms, and low-frequency rTMS to the left temporo-parietal cortex (TPC) to treat auditory hallucinations (AH) and overall positive symptoms.

RESULTS

When analyzing controlled (active arms) and uncontrolled studies together, the effect sizes showed significant and moderate effects of rTMS on negative and positive symptoms (based on PANSS-N or SANS, and PANSS-P or SAPS, respectively). However, the analysis for the sham-controlled studies revealed a small non-significant effect size for negative (0.27, p=0.417) and for positive symptoms (0.17, p=0.129). When specifically analyzing AH (based on AHRS, HCS or SAH), the effect size for the sham-controlled studies was large and significant (1.04; p=0.002).

CONCLUSIONS

These meta-analyses support the need for further controlled, larger trials to assess the clinical efficacy of rTMS on negative and positive symptoms of schizophrenia, while suggesting the need for exploration for alternative stimulation protocols.