Clinical efficacy and safety of repetitive transcranial magnetic stimulation in acute bipolar depression

Toward a neurocircuit-based sequential transcranial magnetic stimulation treatment of pediatric bipolar II disorder

BACKGROUND

Abnormalities in large-scale neuronal networks-the frontoparietal central executive network (CEN)-are consistent findings in bipolar disorder and potential therapeutic targets for transcranial magnetic stimulation (TMS).

OBJECTIVE

The present study aimed to assess the effects of CEN neurocircuit-based sequential TMS on the clinical symptoms and cognitive functions of adolescents with bipolar II disorder.

METHODS

The study was a single-blinded, randomized, placebo-control trial. Participants with DSM-5-defined bipolar disorder II were recruited and randomized to receive either a sham treatment (n = 20) or an active TMS treatment (n = 22). The active group patients were taking medication, with intermittent theta burst stimulation (iTBS) treatment provided as adjunctive treatment targeting the left DLPFC, the left ITG, and the left PPC nodes consecutively. Patients completed the measurements of HAMD and the Das-Naglieri Cognition Assessment System at baseline and 3 weeks after the intervention.

RESULTS

A significant group-by-time interaction was observed in the HAMD, total cognition, and planning. Post-hoc analysis revealed that patients in the active group significantly improved HAMD scores following neurostimulation. Moreover, within-subject analysis indicated that the active group significantly improved in scores of total cognition and planning, while the sham group did not. No significant differences were seen in the other cognitive measures.

CONCLUSION

The neurocircuit-based sequential TMS protocol targeting three CEN nodes, in conjunction with medication, safely and effectively improved depressive symptoms and cognitive function in adolescents with bipolar II disorder.

Continuous theta burst stimulation for bipolar depression: A multicenter, double-blind randomized controlled study exploring treatment efficacy and predictive potential of kynurenine metabolites

BACKGROUND

While theta burst stimulation (TBS) shows promise in Major Depressive Disorder (MDD), its effectiveness in bipolar depression (BD-D) remains uncertain. Optimizing treatment parameters is crucial in the pursuit of rapid symptom relief. Moreover, aligning with personalized treatment strategies and increased interest in immunopsychiatry, biomarker-based stratification of patients most likely to benefit from TBS might improve remission rates. We investigated treatment effectiveness of continuous TBS (cTBS) compared to sham in BD-D, and assessed the capacity of plasma kynurenine pathway metabolites to predict treatment outcome.

METHODS

Thirty-seven patients with BD-D underwent accelerated active or sham cTBS treatment in a multicenter, double-blind, randomized controlled trial. Depressive symptoms were measured with the 17-item Hamilton Depression Rating Scale (HDRS-17) before treatment (T0), 3-4 days posttreatment (T1) and 10-11 days posttreatment (T2). Plasma tryptophan, kynurenine, kynurenic acid and quinolinic acid concentrations were quantified with ELISA. Linear mixed models were used for statistical analyses.

RESULTS

Although the total sample showed depressive symptom improvement, active cTBS did not demonstrate greater symptom alleviation compared to sham. However, higher baseline quinolinic acid significantly predicted symptom improvement in the active treatment group, not in sham-stimulated patients.

LIMITATIONS

The modest sample size limited the power to detect significant differences with regard to treatment effect. Also, the follow-up period was 10-11 days, whereas similar studies usually follow up for at least one month.

CONCLUSION

More research is required to optimize cTBS for BD-D and explore the involvement of quinolinic acid in treatment outcome.

Female sex and age-based advantage of simulated electric field in TMS to the prefrontal cortex in schizophrenia and mood disorders

This study investigates computational models of electric field strength for transcranial magnetic stimulation (TMS) of the left dorsolateral prefrontal cortex (DLPFC) based on individual MRI data of patients with schizophrenia (SZ), major depressive disorder (MDD), bipolar disorder (BP), and healthy controls (HC). In addition, it explores the association of electric field intensities with age, gender and intracranial volume. The subjects were 23 SZ (12 male, mean age = 45.30), 24 MDD (16 male, mean age = 43.57), 23 BP (16 male, mean age = 39.29), 23 HC (13 male, mean age = 40.91). Based on individual MRI sequences, electric fields were computationally modeled by two independent investigators using SimNIBS ver. 2.1.1. There was no significant difference in electric field strength between the groups (HC vs SZ, HC vs MDD, HC vs BP, SZ vs MDD, SZ vs BP, MDD vs BP). Female subjects showed higher electric field intensities in widespread areas than males, and age was positively significantly associated with electric field strength in the left parahippocampal area as observed. Our results suggest differences in electric field strength of left DLPFC TMS for gender and age. It may open future avenues for individually modeling TMS based on structural MRI data.

Clinical efficacy of deep transcranial magnetic stimulation (dTMS) in psychiatric and cognitive disorders: A systematic review

Deep transcranial magnetic stimulation (dTMS) has gained attention as an enhanced form of traditional TMS, targeting broader and deeper regions of the brain. However, a fulsome synthesis of dTMS efficacy across psychiatric and cognitive disorders using sham-controlled trials is lacking. We systematically reviewed 28 clinical trials comparing active dTMS to a sham/controlled condition to characterize dTMS efficacy across diverse psychiatric and cognitive disorders. A comprehensive search of APA PsycINFO, Cochrane, Embase, Medline, and PubMed databases was conducted. Predominant evidence supports dTMS efficacy in patients with obsessive-compulsive disorder (OCD; n = 2), substance use disorders (SUDs; n = 8), and in those experiencing depressive episodes with major depressive disorder (MDD) or bipolar disorder (BD; n = 6). However, the clinical efficacy of dTMS in psychiatric disorders characterized by hyperactivity or hyperarousal (i.e., attention-deficit/hyperactivity disorder, posttraumatic stress disorder, and schizophrenia) was heterogeneous. Common side effects included headaches and pain/discomfort, with rare but serious adverse events such as seizures and suicidal ideation/attempts. Risk of bias ratings indicated a collectively low risk according to the Grading of Recommendations, Assessment, Development, and Evaluations checklist (Meader et al., 2014). Literature suggests promise for dTMS as a beneficial alternative or add-on treatment for patients who do not respond well to traditional treatment, particularly for depressive episodes, OCD, and SUDs. Mixed evidence and limited clinical trials for other psychiatric and cognitive disorders suggest more extensive research is warranted. Future research should examine the durability of dTMS interventions and identify moderators of clinical efficacy.

Cost-utility analysis of adjunct repetitive transcranial magnetic stimulation for treatment resistant bipolar depression

OBJECTIVE

To evaluate the cost-effectiveness of repetitive transcranial magnetic stimulation (rTMS) as an adjunct to standard care from an Australian health sector perspective, compared to standard care alone for adults with treatment-resistant bipolar depression (TRBD).

METHODS

An economic model was developed to estimate the cost per disability-adjusted life-year (DALY) averted and quality-adjusted life-year (QALY) gained for rTMS added to standard care compared to standard care alone, for adults with TRBD. The model simulated the time in three health states (mania, depression, residual) over one year. Response to rTMS was sourced from a meta-analysis, converted to a relative risk and used to modify the time in the depressed state. Uncertainty and sensitivity tested the robustness of results.

RESULTS

Base-case incremental cost-effectiveness ratios (ICERs) were $72,299 per DALY averted (95 % Uncertainty Interval (UI): $60,915 to $86,668) and $46,623 per QALY gained (95 % UI: $39,676 - $55,161). At a willingness to pay (WTP) threshold of $96,000 per DALY averted, the base-case had a 100 % probability of being marginally cost-effective. At a WTP threshold of $64,000 per QALY gained, the base-case had a 100 % probability of being cost-effective. Sensitivity analyses decreasing the number of sessions provided, increasing the disability weight or the time spent in the depression state for standard care improved the ICERs for rTMS.

CONCLUSIONS

Dependent on the outcome measure utilised and assumptions, rTMS would be considered a very cost-effective or marginally cost-effective adjunct to standard care for TRBD compared to standard care alone.

Right ventrolateral and left dorsolateral 10 Hz transcranial magnetic stimulation as an add-on treatment for bipolar I and II depression: a double-blind, randomised, three-arm, sham-controlled study

OBJECTIVES

Despite the clinical importance of bipolar depression (BDE), effective treatment options are still limited. Transcranial magnetic stimulation (rTMS) has proven of moderate efficacy in major depression, but the evidence remains inconclusive for BDE.

METHODS

A 4-week, double-blind, randomised, parallel-group, sham-controlled study (trial ID ISRCTN77188420) explored the benefits of 10 Hz MRI-guided right ventrolateral (RVL) rTMS and left dorsolateral (LDL) rTMS as add-on treatments for BDE. Outcome measures included changes in the Montgomery-Åsberg Depression Rating Scale (MADRS) score, self-assessment, response and remission rates, and side effects.

RESULTS

Sixty patients were randomly assigned to study groups, and forty-six completed the double-blind phase. The mean change from baseline to Week 4 in MADRS was greater in both active groups compared to the sham, yet differences did not achieve significance (RVL vs sham: -4.50, 95%CI -10.63 to 1.64, p = 0.3; LDL vs sham: -4.07, 95%CI -10.24 to 2.10, p = 0.4). None of the other outcome measures yielded significant results.

CONCLUSIONS

While not demonstrating the superiority of either 10 Hz rTMS over sham, with the limited sample size, we can not rule out a moderate yet clinically meaningful effect. Further well-powered studies are essential to elucidate the role of rTMS in managing BDE.

Real-world retrospective study of repetitive transcranial magnetic stimulation (TMS) treatment for bipolar and unipolar depression using TMS registry data in Tokyo

Despite the prevalence of empirical practice, evidence supporting the use of repetitive transcranial magnetic stimulation (rTMS) in treating bipolar depression (BD) is sparse compared to that for unipolar depression. Therefore, this study aimed to conduct a retrospective observational analysis using TMS registry data to compare the efficacy of rTMS treatment for BD and unipolar depression. Data from 20 patients diagnosed with unipolar and BD were retrospectively extracted from the TMS registry to ensure age and sex matching. The primary outcomes of this registry study were measured using the 21-item Hamilton Depression Rating Scale (HAM-D21) and Montgomery-Åsberg Depression Rating Scale (MADRS). Analysis did not reveal significant differences between the two groups in terms of depression severity, motor threshold, or stimulus intensity at baseline. Similarly, no significant differences were observed in absolute or relative changes in the total HAM-D21 and MADRS scores. Furthermore, the response and remission rates following rTMS treatment did not differ significantly between groups. The only adverse event reported in this study was scalp pain at the stimulation site; however, the incidence and severity were not significantly different between the groups. In conclusion, this retrospective study, using real-world TMS registry data, suggests that rTMS treatment for BD could be as effective as that for unipolar depression. These findings underscore the need for further validation in prospective randomized controlled trials with larger sample sizes.

The use of theta burst stimulation in patients with schizophrenia - A systematic review

Transcranial magnetic stimulation (TMS) can offer therapeutic benefits and provide value in neurophysiological research. One of the newer TMS paradigms is theta burst stimulation (TBS) which can be delivered in two patterns: continuous (cTBS - inducing LTD-like effects) and intermittent (iTBS - inducing LTP-like effects). This review paper aims to explore studies that have utilized TBS protocols over different areas of the cortex to study the neurophysiological functions and treatment of patients with schizophrenia. PubMed was searched using the following keywords "schizophrenia", "schizoaffective", or "psychosis", and "theta burst stimulation". Out of the 90 articles which were found, thirty met review inclusion criteria. The inclusion criteria included studying the reported effect (clinical, physiological, or both) of at least one session of TBS on human subjects, and abstracts (at minimum) must have been in English. The main target areas included prefrontal cortex (12 studies - 10 dorsolateral prefrontal cortex (DLPFC), 2 dorsomedial prefrontal cortex (DMPFC)) vermal cerebellum (5), and temporo-parietal cortex (8). Other target areas included inferior parietal lobe (2), and motor cortex (3). TBS neurophysiological effect was explored in 5 studies using functional magnetic resonance image (fMRI), magnetic resonance spectroscopy (MRS), electroencephalography (EEG), electromyography (EMG) and positron emission topography (PET) scan. Overall, TBS can offer great therapeutic potential as it is well-tolerated, feasible, and has few, if any, adverse effects. TBS may be targeted to treat specific symptomatology, as an augmenting intervention to pharmacotherapy, or even improving patient's insight into their diagnosis.

Neuroimaging Correlates of Treatment Response to Transcranial Magnetic Stimulation in Bipolar Depression: A Systematic Review

Transcranial magnetic stimulation (TMS) has become a promising strategy for bipolar disorder (BD). This study reviews neuroimaging findings, indicating functional, structural, and metabolic brain changes associated with TMS in BD. Web of Science, Embase, Medline, and Google Scholar were searched without any restrictions for studies investigating neuroimaging biomarkers, through structural magnetic resonance imaging (MRI), diffusion tensor imaging (DTI), functional MRI (fMRI), magnetic resonance spectroscopy (MRS), positron emission tomography (PET), and single photon emission computed tomography (SPECT), in association with response to TMS in patients with BD. Eleven studies were included (fMRI = 4, MRI = 1, PET = 3, SPECT = 2, and MRS = 1). Important fMRI predictors of response to repetitive TMS (rTMS) included higher connectivity of emotion regulation and executive control regions. Prominent MRI predictors included lower ventromedial prefrontal cortex connectivity and lower superior frontal and caudal middle frontal volumes. SPECT studies found hypoconnectivity of the uncus/parahippocampal cortex and right thalamus in non-responders. The post-rTMS changes using fMRI mostly showed increased connectivity among the areas neighboring the coil. Increased blood perfusion was reported post-rTMS in PET and SPECT studies. Treatment response comparison between unipolar depression and BD revealed almost equal responses. Neuroimaging evidence suggests various correlates of response to rTMS in BD, which needs to be further replicated in future studies.

Real world transcranial magnetic stimulation for major depression: A multisite, naturalistic, retrospective study

BACKGROUND

In 2008, the U.S. FDA approved rTMS as a treatment against medication-resistant depression. However, real-world rTMS outcomes remain understudied. This study investigates how rTMS for depression is delivered in routine clinical practice in France, and measures its effectiveness as well as its moderators.

METHODS

Five centers provided retrospective data on patients who were treated with rTMS for treatment-resistant depression from January 2015 to December 2020. Patients were assessed twice using a hetero-questionnaire, with baseline and immediate post-treatment assessments. We conducted univariate analyses to study which factors were significantly associated with rTMS effectiveness. We then included age, gender, and significant factors in a multivariate model.

RESULTS

We collected data from 435 patients with a mean age of 51.27 (14.91): 66 % were female, and 26 % suffered from bipolar depression. Stimulation was delivered using four different stimulation parameters: 1 Hz (7 % of the individuals), 10 Hz (43 %), 20 Hz (12 %), and 50 Hz (intermittent Theta Burst Stimulation, iTBS) (38 %). The mean improvement of depressive symptoms was 33 % (p < 0.001, effect-size: 0.79). Response and remission rates were of 31 % and 22.8 %, respectively. In the multivariate analysis, improvement in depressive symptoms was associated with higher baseline symptoms.

CONCLUSION

This is one of the largest studies that investigates, with careful clinician-rated scales by trained psychiatrists, the effect of rTMS in naturalistic settings. Repetitive TMS appears to be effective in routine clinical practice, although its efficacy could be improved by analyzing predictors of response, as well as personalized targeting of specific brain areas.

Safety and Efficacy of Continuous Theta Burst "Intensive" Stimulation in Acute-Phase Bipolar Depression: A Pilot, Exploratory Study

OBJECTIVES

Repetitive transcranial magnetic stimulation efficacy in unipolar depression is known, but its efficacy in acute-phase bipolar depression is at best modest. Citing differential right dorsolateral prefrontal cortex hyperconnectivity implicated in BD, we aimed to study the effect of novel continuous theta burst stimulation (cTBS) targeting right dorsolateral prefrontal cortex in a randomized rater blinded placebo control design.

MATERIAL AND METHODS

Nineteen patients aged 18 to 59 years (baseline Hamilton Depression Rating Scale [HAM-D] 17 severity score >18) were randomly allocated to active cTBS (n = 11) and sham cTBS (n = 9) groups using block randomization method. They received 15 cTBS sessions (burst of 3 pulses delivered at 50 Hz, repeated every 200 ms at 5 Hz, 600 pulses per session), 3 sessions per day (total of 1800 pulses) for 5 days in a week at 80% resting motor threshold. The HAM-D, Beck Depression Inventory, Hamilton Anxiety Rating Scale, World Health Organization's abbreviated quality of life assessment, and Changes in Sexual Functioning Questionnaire were assessed at baseline, after the last session, and at 2 weeks after repetitive transcranial magnetic stimulation. Intention-to-treat analysis was conducted and missing values (2 patients) were replaced using the last observation carried forward method.

RESULTS

On repeated measures analysis of variance, a significant within-group time effect (from pretreatment to 2 weeks after TBS) for HAM-D ( F = 15.091, P < 0.001), Beck Depression Inventory ( F = 22.376, P < 0.001), Hamilton Anxiety Rating Scale ( F = 18.290, P < 0.001), Changes in Sexual Functioning Questionnaire ( F = 9.281, P = 0.001), and World Health Organization's abbreviated quality of life assessment ( F = 24.008, P < 0.001). The integrity of the blind assessed by the guess matrix was good. When significant between group*time effect was compared, none of the variables retained statistical significance. No major adverse effects were reported, and none of the patients discontinued the trial because of adverse effects.

CONCLUSIONS

Our trial concludes that although safe and well tolerated, the therapeutic efficacy of intensive intermittent TBS in acute-phase bipolar depression is inconclusive. Choice of lower total number to sessions and smaller intersession interval along with small sample size limit the study findings.

Effect of high-definition transcranial direct current stimulation on improving depression and modulating functional activity in emotion-related cortical-subcortical regions in bipolar depression

Preliminary studies have suggested that transcranial direct current stimulation (tDCS) is effective for bipolar depression, However, brain correlates of the depression alleviating are unclear. To determine the efficacy and safety of tDCS as an add-on treatment for patients with bipolar depression and further to identify the effect of tDCS on the resting-state brain activities, we recruited fifty patients with bipolar depression to complete the double-blind, sham-controlled and randomized clinical trial. Fourteen sessions of tDCS were performed once a day for 14 days. The anode was placed over F3 with return electrodes placed at FP1, FZ, C3 and F7. Regional homogeneity (ReHo) was examined on 50 patients with bipolar depression before and after 14-day active or sham tDCS. Patients in the active group showed significantly superior alleviating the depression symptoms compared with those receiving sham. The active group after 14-day active tDCS showed increased ReHo values in the orbitofrontal cortex and middle frontal gyrus and decreased ReHo values in subcortical structures including hippocampus, parahippocampa gyrus, amygdala, putamen and lentiform nucleus. The reduction of depression severity showed positive correlation of increased ReHo values in the orbitofrontal cortex and middle frontal gyrus and negative correlation of altered ReHo values in the putamen and lentiform. TDCS was an effective and safe add-on intervention for this small bipolar depression sample. The reduction of depression induced by tDCS is associated with a modulation of neural synchronization in the cortical and subcortical structures (ReHo values) within an emotion-related brain network.

Brain stimulation treatment for bipolar disorder

AIMS

Bipolar disorders are clinically complex, chronic and recurrent disorders. Few treatment options are effective across hypomanic, manic, depressive and mixed states and as continuation or maintenance treatment after initial symptom remission. The aim of this review was to provide an up-to-date overview of research on the efficacy, tolerability and cognitive effects of electroconvulsive therapy (ECT), transcranial magnetic stimulation (TMS), transcranial direct current stimulation (tDCS), magnetic seizure therapy (MST), deep brain stimulation (DBS) and vagus nerve stimulation (VNS).

METHODS

References included in this review were identified through multiple searches of the Embase, PubMed/MEDLINE and APA PsycINFO electronic databases for articles published from inception until February 2022. Published reviews, meta-analyses, randomised controlled trials and recent studies were prioritised to provide a comprehensive and up-to-date overview of research on brain stimulation in patients with bipolar disorders.

RESULTS

The evidence base for brain stimulation as an add-on or alternative to pharmacological and psychological treatments in patients with bipolar disorders is limited but rapidly expanding. Brain stimulation treatments represent an opportunity to treat all bipolar disorder states, including cognitive dysfunction during euthymic periods.

CONCLUSION

Whilst findings to date have been encouraging, larger randomised controlled trials with long-term follow-up are needed to clarify important questions regarding treatment efficacy and tolerability, the frequency of treatment-emergent affective switches and effects on cognitive function.

Is Repetitive Transcranial Magnetic Stimulation (RTMS) a Promising Therapeutic Intervention for Eating Disorders and Obesity? Clinical Considerations Based on a Meta-Analytic Review

Objective

Repetitive Transcranial Magnetic Stimulation (rTMS) has been introduced to treat eating disorders (EDs), especially Anorexia, Bulimia Nervosa (AN and BN) and other EDs not otherwise specified (NOS). Provisional rTMS single-case studies and clinical trials have been carried out for the treatment of binge eating disorder (BED) and obesity. However, it is still unclear whether and to what extent rTMS might be considered an effective intervention for these conditions.

Method

This meta-analysis includes 15 independent studies examining the clinical effects of rTMS among different EDs and obesity (N = 402 patients). Several primary and secondary treatment outcomes have been considered. Cohen's d was used as an effect size measure. The analyses estimate heterogeneity across findings, sources of variability and publication bias together with an assessment of the quality of the studies.

Results

The analyses show that rTMS induced large improvements in body mass index (BMI) among obese individuals. Null clinical effects have been detected for primary outcomes (i.e., BMI, binge eating and compensatory behaviors; urge to binge and to eat; severity of EDs symptoms) among individuals with AN, BN and other EDs-NOS. rTMS shows moderate therapeutic effects on the affective functioning (i.e., negative affectivity, depressive and anxious symptoms) of individuals with EDs. rTMS should be considered a promising intervention for the treatment of obesity.

Conclusions

This evidence might provisionally support the hypothesis on the implementation of rTMS for BED. Furthermore, rTMS could be included as an ancillary intervention for the other EDs, especially considering secondary treatment outcomes. Future controlled trials are needed to clarify the clinical effects of rTMS for EDs.

A New Treatment Protocol of Combined High-Dose Levothyroxine and Repetitive Transcranial Magnetic Stimulation for the Treatment of Rapid-Cycling Bipolar Spectrum Disorders: A Cohort Evaluation of 55 Patients

Background: Bipolar spectrum disorders (BSD) are highly disabling, with rapid cycling being treatment resistant. High-dose levothyroxine (HDT) has been reported to be effective. Diagnosis is associated with mutations in thyroid-activating enzymes and cerebral transporter protein carrier. Repetitive transcranial magnetic stimulation (rTMS) has neuroplastic effects. Methods: We report data on 55 severely symptomatic patients with rapid-cycling BSD treated with a combination protocol of HDT and rTMS. Of the patients, 31 patients (56.4%) were female and 40 (72.7%) had at least one additional diagnosis. Results: Patients were evaluated at three monthly intervals after acute treatment. Remission was measured using the Sheehan Disability Scale (SDS). The average number of medications prescribed was 1.8, with 32 patients (58.2%) needing only levothyroxine. The average dose of levothyroxine was 303.7 mcg (50 mcg−1000 mcg). A total of 53 patients were in remission (96.4%), with an average duration of 2.0 years. The SDS scores decreased significantly (Cohen’s d = 2.61 (95% C.I. 1.81 to 2.83, p < 0.001). One patient had reversible side effects. A total of 52 (94.3%) patients had Deiodinase 1 and 2 (DiO1/DiO2) or SLCO1C1 protein carrier gene mutations. Conclusion: The data support the safety and acceptability of combined HDT/rTMS. Patients achieved long remissions with substantial improvements in quality of life.

A Different rTMS Protocol for a Different Type of Depression: 20.000 rTMS Pulses for the Treatment of Bipolar Depression Type II

In this open-label naturalistic study, we assess the feasibility, tolerability, and effectiveness of a repetitive transcranial magnetic stimulation protocol with a reduced total pulse number for treating patients suffering from bipolar disorder type II. All patients received one rTMS treatment session of 1000 pulses for 20 consecutive working days, accumulating to 20.000 rTMS pulses applied over 4 weeks. We measured the patients’ symptoms before the start, halfway through, directly after, and one month after treatment. We quantified the depression symptoms using both the Beck depression inventory scale and the symptom checklist-90 depression subscale. Patients showed a significant reduction in depression symptoms directly after treatment and an even further reduction one month after treatment. The remission rates were at 26% halfway through treatment (after the 10th session), 61% directly after treatment (after the 20th session), and increased to 78% at the 1-month follow-up. Importantly, the protocol proved to be feasible and highly tolerable in this patient population, with no adverse effects being reported. Considering these positive results, further research should focus on replicating these findings in larger clinical samples with control groups and longer follow-up periods, while potentially adding maintenance sessions to optimize the treatment effect and stability for bipolar disorder type II patients.

The Use of Repetitive Transcranial Magnetic Stimulations for the Treatment of Bipolar Disorder: A Scoping Review

Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive neuromodulation technique that involves the application of magnetic pulses on hyperactive or hypoactive cortical brain areas. rTMS is considered a high therapeutic tool in many neuropsychiatric conditions. Despite its wide and continuous usage for the treatment of psychiatric disorders, information about the use of rTMS in bipolar disorders is limited and not well-established in the literature. Objectives: This scoping review aims to explore the literature available regarding the application of rTMS for the management of bipolar disorders, to garner evidence in support of it uses in the management of bipolar disorders, and for recommendations on future clinical and research work. Method: We electronically conducted a data search in five research databases (MEDLINE, CINAHL, Psych INFO, SCOPUS, and EMBASE) using all identified keywords across all the databases to identify evidence-based studies. Articles were included if they were published randomized control designs aimed at the use of rTMS in the management of bipolar disorders. Overall, nine studies were eligible for this review. The search results are up to date as of the final date of data search-20 December 2020. Only full-text published articles written in English were reviewed. Review articles on treatment with rTMS for conditions either than bipolar disorders were excluded. Conclusion: The application of rTMS intervention for bipolar disorders looks promising despite the diversity of its outcomes and its clinical significance. However, to be able to draw a definite conclusion on the clinical effectiveness of the technique, more randomized controlled studies with well-defined stimulation parameters need to be conducted with large sample sizes in the future.

Neural network of bipolar disorder: Toward integration of neuroimaging and neurocircuit-based treatment strategies

Bipolar disorder (BD) is a complex psychiatric disorder characterized by dysfunctions in three domains including emotional processing, cognitive processing, and psychomotor dimensions. However, the neural underpinnings underlying these clinical profiles are not well understood. Based on the reported data, we hypothesized that (i) the core neuropathology in BD is damage in fronto-limbic network, which is associated with emotional dysfunction; (ii) changes in intrinsic brain network, such as sensorimotor network, salience network, default-mode network, central executive network are associated with impaired cognition function; and (iii) beyond the dopaminergic-driven basal ganglia-thalamo-cortical motor circuit modulated by other neurotransmitter systems, such as serotonin (subcortical-cortical modulation), the sensorimotor network and related motor function modulated by other non-motor networks such as the default-mode network are involved in psychomotor function. In this review, we propose a neurocircuit-based clinical characteristics and taxonomy to guide the treatment of BD. We draw on findings from neuropsychological and neuroimaging studies in BD and link variations in these clinical profiles to underlying neurocircuit dysfunctions. We consider pharmacological, psychotherapy, and neuromodulatory treatments that could target those specific neurocircuit dysfunctions in BD. Finally, it is suggested that the methods of testing the neurocircuit-based taxonomy and important limitations to this approach should be considered in future.

Repetitive transcranial magnetic stimulation (rTMS) in bipolar disorder: A systematic review

OBJECTIVES

Repetitive transcranial magnetic stimulation (rTMS) is commonly used in unipolar depression; yet, its evidence in bipolar disorder (BD) is limited. We sought to review the evidence on the use of rTMS across the different stages of BD.

METHODS

MEDLINE database was systematically searched using the PubMed interface following the PRISMA guidelines. Inclusion criteria were as follows: (i) randomized clinical trials (RCTs), open-label studies, and case series; (ii) specific evaluation of the treatment outcomes using psychometric scales; (iii) clinical studies in adults; and (iv) articles in the English language. The systematic review has been registered on PROSPERO (CRD42020192788).

RESULTS

Thirty-one papers were included in the review. Most studies included participants diagnosed with a bipolar depressive episode (N = 24), have yielded mixed findings, and have yet to reach a consensus on the most effective rTMS protocol. Few studies examined the effect of rTMS during manic (N = 5) or mixed episode (N = 1), or as maintenance treatment (N = 1). The limited data thus far suggest rTMS to be relatively safe and well tolerated. Small sample sizes, heterogeneity among study designs, patients and control groups recruited, rTMS parameters, and outcome measures are among the most significant limitations to these studies.

CONCLUSION

The current data regarding the application of rTMS in BD patients remain limited. More adequately powered sham-controlled studies are required to verify its efficacy. Large-scale clinical trials are needed to also determine whether its effects extend to manic and mixed episodes, as well as its role in mood stabilization and amelioration of suicidal behavior.

A new approach for the treatment of subthreshold bipolar disorders: Targeted high dose levothyroxine and repetitive transcranial magnetic stimulation for mitochondrial treatment

Bipolar spectrum disorder includes Bipolar I, Bipolar II and subthreshold bipolar disorders (BD). The condition is highly prevalent, disabling and associated with high mortality. Failure of diagnosis is high. Subthreshold presentations present as 4 or more changes in polarity, are generally less responsive to standard treatment and as a result, drug combinations are often needed. High Dose Levothyroxine (HDT) has been reported to be safe and effective with this condition. Treatment response has been associated with mutations in thyroid activating enzymes and intra cerebral transporter protein carrier. Repetitive Transcranial Magnetic Stimulation (rTMS) has been shown to be effective in bipolar depression and has been proved to have neuroplastic effect. Present authors had reported clinical evidence of safe and effective use of a combination treatment protocol. Potential mechanisms of action of the combined treatment protocol and the role of mitochondria function are discussed.

Baseline Clinical and Neuroimaging Biomarkers of Treatment Response to High-Frequency rTMS Over the Left DLPFC for Resistant Depression

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) has proven to be an efficient treatment option for patients with treatment-resistant depression (TRD). However, the success rate of this method is still low, and the treatment outcome is unpredictable. The objective of this study was to explore clinical and structural neuroimaging factors as potential biomarkers of the efficacy of high-frequency (HF) rTMS (20 Hz) over the left dorso-lateral pre-frontal cortex (DLPFC).

METHODS

We analyzed the records of 131 patients with mood disorders who were treated with rTMS and were assessed at baseline at the end of the stimulation and at 1 month after the end of the treatment. The response is defined as a 50% decrease in the MADRS score between the first and the last assessment. Each of these patients underwent a T1 MRI scan of the brain, which was subsequently segmented with FreeSurfer. Whole-brain analyses [Query, Design, Estimate, Contrast (QDEC)] were conducted and corrected for multiple comparisons. Additionally, the responder status was also analyzed using binomial multivariate regression models. The explored variables were clinical and anatomical features of the rTMS target obtained from T1 MRI: target-scalp distance, DLPFC gray matter thickness, and various cortical measures of interest previously studied.

RESULTS

The results of a binomial multivariate regression model indicated that depression type (p = 0.025), gender (p = 0.010), and the severity of depression (p = 0.027) were found to be associated with response to rTMS. Additionally, the resistance stage showed a significant trend (p = 0.055). Whole-brain analyses on volume revealed that the average volume of the left part of the superior frontal and the caudal middle frontal regions is associated with the response status. Other MRI-based measures are not significantly associated with response to rTMS in our population.

CONCLUSION

In this study, we investigated the clinical and neuroimaging biomarkers associated with responsiveness to high-frequency rTMS over the left DLPFC in a large sample of patients with TRD. Women, patients with bipolar depressive disorder (BDD), and patients who are less resistant to HF rTMS respond better. Responders present a lower volume of the left part of the superior frontal gyrus and the caudal middle frontal gyrus. These findings support further investigation into the use of clinical variables and structural MRI as possible biomarkers of rTMS treatment response.

Treatment of mixed depression with theta-burst stimulation (TBS): results from a double-blind, randomized, sham-controlled clinical trial

Mixed depression is probably different in terms of clinical course and response to treatment. Repetitive transcranial magnetic stimulation (rTMS) is well established in non-mixed depression, and theta-burst stimulation (TBS) protocol is replacing conventional protocols because of noninferiority and reduced delivery time. However, TBS has not been adequately studied in mixed states. This study was a double-blind, six-week, sham-controlled, and randomized clinical trial of bilateral TBS targeting the right and left dorsolateral prefrontal cortex, respectively. Adults with bipolar and major depressive disorder experiencing an acute mixed depression were eligible if they had not benefited from a first- or second-line treatment for acute unipolar or bipolar depression recommended by the Canadian Network for Mood and Anxiety Treatments. Out of 100 patients included, 90 composed modified intention-to-treat sample, which was patients that completed at least one week of the intervention. There were no significant differences in Montgomery-Asberg depression rating scale score changes (least squares mean difference between groups at week 3, -0.06 [95% CI, - 3.39 to 3.51; P = 0.97] in favor of sham TBS). Response and remission rates per MADRS were also not statistically different among active and sham groups (35.7% vs. 43.7%, and 28.5% vs. 37.5% respectively at week 6, ps > 0.51). No other analyses from baseline to weeks 3 or 6 revealed significant time x group interaction or mean differences among groups in the mITT sample. Bilateral TBS targeting the DLPFC is not efficacious as an add-on treatment of acute bipolar and unipolar mixed depression. ClinicalTrials.govIdentifier: NCT04123301.

Repetitive transcranial magnetic stimulation for cognitive function in adults with bipolar disorder: A pilot study

BACKGROUND

Cognitive deficits are prevalent in bipolar disorder and are a significant contributor to negative patient-reported outcomes. Herein we conducted a pilot study of repetitive transcranial magnetic stimulation (rTMS) to improve cognitive function in adults with bipolar disorder.

METHODS

The study was a triple-blinded, randomized, placebo-control trial. Participants (aged 18 to 60) with a diagnosis of DSM-5-defined bipolar disorder (I or II) were recruited and randomized (N=36) to receive either a sham treatment (n=20) or an active rTMS treatment (n=16). Patients completed the Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) Consensus Cognitive Battery (MCCB) at baseline and 1-2 weeks after the rTMS intervention.

RESULTS

A significant group by time interaction was observed in the Hopkins Verbal Learning Test-Revised (HVLT-R), (F (1, 34) = 17.0, p < 0.001, partial η² = 0.33). Post-hoc analysis revealed that although both groups did not significantly differ at baseline (p = 0.58), patients in the active rTMS group significantly improved following neurostimulation (p = 0.02) for HVLT-R. Moreover, within-subject analysis indicated that the active rTMS group significantly improved in score from pre-treatment to post-treatment (p < 0.001), while the sham group did not improve (p = 0.94) for HVLT-R. No significant differences were seen in the other cognitive measures.

LIMITATIONS

The study was conducted in a small sample .

CONCLUSION

This pilot study, which was intended to establish feasibility, suggests that rTMS may offer benefit in select domains of cognitive functioning in bipolar disorder. None of the measures across subdomains revealed a dyscognitive effect.

Comparative efficacy and acceptability of neuromodulation procedures in the treatment of treatment-resistant depression: a network meta-analysis of randomized controlled trials

BACKGROUND

Nearly half of the patients with depression experience suboptimal benefits from antidepressants. Neuromodulation therapies, a kind of technology that can regulate neuronal firing activity by electrical or magnetic stimulation, were introduced to improve this situation. However, the results from clinical trials have been inconsistent.

METHODS

We followed the extension of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement to perform this network meta-analysis (NMA). The results were evaluated by relative risk (RR) for the response, remission, and discontinuation rates.

RESULTS

In total, 49 trials with 2,941 patients were included in this study. Bilateral theta burst stimulation (TBS, RR 5.00, 95% CI 1.11-22.44), priming transcranial magnetic stimulation (pTMS, RR 2.97, 95% CI 1.20-7.39), low-frequency right repetitive transcranial magnetic stimulation (TMS) (LFR-rTMS, RR 2.62, 95% CI 1.56-4.39), high-frequency left repetitive TMS (HFL-rTMS, RR 2.18, 95% CI 1.52-3.13), and bilateral repetitive TMS (BL-rTMS, RR 3.08, 95% CI 1.78-5.31) were demonstrated to have higher response rates than sham control. BL-rTMS (RR 3.12, 95% CI 1.06-9.09) was found to have a higher response rate than deep brain stimulation in this NMA. All measures had the non-inferiority acceptability than the sham-control. BL-rTMS was more acceptable than bitemporal ECT (BT-ECT, RR 0.18, 95% CI 0.03-0.89), while pTMS was more acceptable than BT-ECT (RR 0.08, 95% CI 0.01-0.55), HFL-rTMS (RR 0.34, 95% CI 0.12-0.93), and deep TMS (RR 0.15, 95% CI 0.02-0.96).

CONCLUSION

Besides electroconvulsive therapy (ECT), rTMS, priming TMS, and bilateral TBS proved effective for patients with treatment-resistant depression (TRD). BL-rTMS showed high efficacy and acceptability, and bilateral TBS had the potential to be the most efficacious neuromodulation measures.

Examining and Modulating Neural Circuits in Psychiatric Disorders With Transcranial Magnetic Stimulation and Electroencephalography: Present Practices and Future Developments

Transcranial magnetic stimulation (TMS) is a noninvasive brain stimulation technique uniquely equipped to both examine and modulate neural systems and related cognitive and behavioral functions in humans. As an examination tool, TMS can be used in combination with EEG (TMS-EEG) to elucidate directly, objectively, and noninvasively the intrinsic properties of a specific cortical region, including excitation, inhibition, reactivity, and oscillatory activity, irrespective of the individual's conscious effort. Additionally, when applied in repetitive patterns, TMS has been shown to modulate brain networks in healthy individuals, as well as ameliorate symptoms in individuals with psychiatric disorders. The key role of TMS in assessing and modulating neural dysfunctions and associated clinical and cognitive deficits in psychiatric populations is therefore becoming increasingly evident. In this article, the authors review TMS-EEG studies in schizophrenia and mood disorders, as most TMS-EEG studies to date have focused on individuals with these disorders. The authors present the evidence on the efficacy of repetitive TMS (rTMS) and theta burst stimulation (TBS), when targeting specific cortical areas, in modulating neural circuits and ameliorating symptoms and abnormal behaviors in individuals with psychiatric disorders, especially when informed by resting-state and task-related neuroimaging measures. Examples of how the combination of TMS-EEG assessments and rTMS and TBS paradigms can be utilized to both characterize and modulate neural circuit alterations in individuals with psychiatric disorders are also provided. This approach, along with the evaluation of the behavioral effects of TMS-related neuromodulation, has the potential to lead to the development of more effective and personalized interventions for individuals with psychiatric disorders.

Circadian depression: A mood disorder phenotype

Major mood syndromes are among the most common and disabling mental disorders. However, a lack of clear delineation of their underlying pathophysiological mechanisms is a major barrier to prevention and optimised treatments. Dysfunction of the 24-h circadian system is a candidate mechanism that has genetic, behavioural, and neurobiological links to mood syndromes. Here, we outline evidence for a new clinical phenotype, which we have called 'circadian depression'. We propose that key clinical characteristics of circadian depression include disrupted 24-h sleep-wake cycles, reduced motor activity, low subjective energy, and weight gain. The illness course includes early age-of-onset, phenomena suggestive of bipolarity (defined by bidirectional associations between objective motor and subjective energy/mood states), poor response to conventional antidepressant medications, and concurrent cardiometabolic and inflammatory disturbances. Identifying this phenotype could be clinically valuable, as circadian-targeted strategies show promise for reducing depressive symptoms and stabilising illness course. Further investigation of underlying circadian disturbances in mood syndromes is needed to evaluate the clinical utility of this phenotype and guide the optimal use of circadian-targeted interventions.

Efficacy of Active vs Sham Intermittent Theta Burst Transcranial Magnetic Stimulation for Patients With Bipolar Depression: A Randomized Clinical Trial

IMPORTANCE

Major depressive episodes in bipolar disorder are common and debilitating. Repetitive transcranial magnetic stimulation is well established in the treatment of major depressive disorder, and the intermittent theta burst stimulation (iTBS) protocol is replacing conventional protocols because of noninferiority and reduced delivery time. However, iTBS has not been adequately studied in bipolar disorder and, therefore, its efficacy is uncertain.

OBJECTIVE

To determine whether iTBS to the left dorsolateral prefrontal cortex (LDLPFC) is safe and efficacious in the treatment of acute bipolar depression.

DESIGN, SETTING, AND PARTICIPANTS

This study was a double-blind, 4-week, randomized clinical trial of iTBS targeting the LDLPFC. Two Canadian academic centers recruited patients between 2016 and 2020. Adults with bipolar disorder type I or type II experiencing an acute major depressive episode were eligible if they had not benefited from a first-line treatment for acute bipolar depression recommended by the Canadian Network for Mood and Anxiety Treatments and were currently treated with a mood stabilizer, an atypical antipsychotic, or their combination. Seventy-one participants were assessed for eligibility, and 37 were randomized to daily sham iTBS or active iTBS using a random number sequence, stratified according to current pharmacotherapy. Data analysis was performed from April to September 2020.

INTERVENTIONS

Four weeks of daily active iTBS (120% resting motor threshold) or sham iTBS to the LDLPFC. Nonresponders were eligible for 4 weeks of open-label iTBS.

MAIN OUTCOMES AND MEASURES

The primary outcome was the change in score on the Montgomery-Asberg Depression Rating Scale from baseline to study end. Secondary outcomes included clinical response, remission, and treatment-emergent mania or hypomania.

RESULTS

The trial was terminated for futility after 37 participants (23 women [62%]; mean [SD] age, 43.86 [13.87] years; age range, 20-68 years) were randomized, 19 to sham iTBS and 18 to active iTBS. There were no significant differences in Montgomery-Asberg Depression Rating Scale score changes (least squares mean difference between groups, -1.36 [95% CI, -8.92 to 6.19; P = .91] in favor of sham iTBS), and rates of clinical response were low in both the double-blind phase (3 of 19 participants [15.8%] in the sham iTBS group and 3 of 18 participants [16.7%] in the active iTBS group) and open-label phase (5 of 21 participants [23.8%]). One active iTBS participant had a treatment emergent hypomania, and a second episode occurred during open-label treatment.

CONCLUSIONS AND RELEVANCE

iTBS targeting the LDLPFC is not efficacious in the treatment of acute bipolar depression in patients receiving antimanic or mood stabilizing agents. Additional research is required to understand how transcranial magnetic stimulation treatment protocols differ in efficacy between unipolar and bipolar depression.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02749006.

Prevention of suicidal behavior in bipolar disorder

BACKGROUND

Excess mortality is a critical hallmark of bipolar disorder (BD) due to co-occurring general medical disorders and especially from suicide. It is timely to review of the status of suicide in BD and to consider the possibility of limiting suicidal risk.

METHODS

We carried out a semi-systematic review of recent research reports pertaining to suicide in BD.

FINDINGS

Suicide risk in BD is greater than with most other psychiatric disorders. Suicide rates (per 100,000/year) are approximately 11 and 4 in the adult and juvenile general populations, but over 200 in adults, and 100 among juveniles diagnosed with BD. Suicide attempt rates with BD are at least 20 times higher than in the adult general population, and over 50 times higher among juveniles. Notable suicidal risk factors in BD include: previous suicidal acts, depression, mixed-agitated-dysphoric moods, rapid mood-shifts, impulsivity, and co-occurring substance abuse. Suicide-preventing therapeutics for BD remain severely underdeveloped. Evidence favoring lithium treatment is stronger than for other measures, although encouraging findings are emerging for other treatments.

CONCLUSIONS

Suicide is a leading clinical challenge for those caring for BD patients. Improved understanding of risk and protective factors combined with knowledge and close follow-up of BD patients should limit suicidal risk. Ethically appropriate and scientifically sound studies of plausible medicinal, physical, and psychosocial treatments aimed at suicide prevention specifically for BD patients are urgently needed.

Efficacy and neurophysiological predictors of treatment response of adjunct bifrontal transcranial direct current stimulation (tDCS) in treating unipolar and bipolar depression

BACKGROUND

Although add-on transcranial direct current stimulation (tDCS) is a promising intervention for treating unipolar (UD) and bipolar depression (BD), its moderate antidepressant efficacy urges research into biomarkers for predicting therapeutic response and achieving highly targeted applications.

METHODS

This open-label trial enrolled UD (N=58) and BD (N=22) patients who had failed 1 or more trials of adequate pharmacologic interventions (ClinicalTrials.gov ID: NCT03287037). Bifrontal tDCS (anode/cathode: F3/F4) was applied using a 2 mA current for 20 min, twice daily, for 5 consecutive weekdays. Depression was measured with Hamilton Depression Rating Scale-17 (HAMD) at baseline, after 10-session stimulation, 1- and 4-week follow-ups. Heart rate (HR) and heart rate variability (HRV) was measured at baseline, during the initial 5 min of the 1^st session, after 10-session stimulation, 1- and 4-week follow-ups. Cognitive performance and other outcomes were also assessed.

RESULTS

Bifrontal tDCS rapidly and equally improved depression in both groups. The effects persisted until the end of the trial. Both groups had similar improvements in cognitive performance, anxiety, and psychosocial functioning. Compared with baseline, increased vagally-mediated HRV was observed one month after tDCS for both groups. A positive correlation was found between HR deceleration within the 1^st session and treatment response after 10-session tDCS only among UD patients, explaining 20% of the variance.

CONCLUSION

tDCS as an adjunct therapy is effective for both UD and BD. Data suggest that the greater the increase in parasympathetic signaling during the 1^st session, the better the clinical response after 10-session tDCS for UD patients.

The efficacy of repetitive transcranial magnetic stimulation (rTMS) for bipolar depression: A systematic review and meta-analysis

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) has established efficacy in the treatment of unipolar depression and a growing evidence base in the treatment of bipolar depression. The objective of this study was to provide an estimate of the efficacy of rTMS in bipolar depression as an up to date synthesis of this literature is lacking.

METHODS

We conducted a systematic review of the sham-controlled randomized controlled trial (RCT) literature examining rTMS in bipolar depression. Studies were included if they included participants with bipolar depression in both sham- and active arms. The primary outcome parameter was rate of clinical response, defined as a 50% reduction as compared to baseline, on an established depression rating scale. Quantitative synthesis was performed using the Maentel-Haenszel random-effects model.

RESULTS

Data from a total of 274 patients from 14 studies were retained in the quantitative synthesis. The response rates were higher in rTMS compared to sham treatment (odds ratio (OR) = 2.72. 95%CI: 1.44-5.14). When stimulation protocols were analysed separately, statistically significant clinical response was only observed for high-frequency rTMS over the left dorsolateral prefrontal cortex (OR = 2.57, 95%CI: 1.17-5.66).

LIMITATIONS

Most data was extracted from trials including very few participants with bipolar depression (predominantly unipolar depression samples). Large confirmatory RCTs of rTMS specifically for bipolar depression are lacking.

CONCLUSION

rTMS seems effective in the treatment of bipolar depression, but dedicated and adequately powered RCTs are needed in order to firmly conclude that rTMS should be offered routinely for the treatment of bipolar depression.

Efficacy and Safety of Deep Transcranial Magnetic Stimulation in Office Workers with Treatment-Resistant Depression: A Randomized, Double-Blind, Sham-Controlled Trial

OBJECTIVES

Major depression is a highly prevalent disorder that causes economic burden in office workers. We conducted a randomized, double-blind, sham-controlled trial to evaluate the efficacy and safety of deep transcranial magnetic stimulation (dTMS) in office workers with treatment-resistant depression.

METHODS

In this study, we randomized office workers taking administrative leave for treatment-resistant major depressive disorder or bipolar disorder with current major depressive episode. dTMS treatment was applied at 120% resting motor threshold with 18 Hz over the left dorsolateral prefrontal cortex. The treatment sessions delivered a total of 1,980 pulses a day, 5 days a week, for 4-6 weeks. The primary outcome was change in the total score on the 21-item Hamilton Depression Rating Scale (HDRS-21) from baseline to the end of study in an intent-to-treat analysis. The secondary outcomes were the response and remission rates. We also assessed changes in cognitive function and adverse events.

RESULTS

Forty patients were randomized to active or sham dTMS groups (1:1). The change in the total score on the HDRS-21 was more significantly improved in the active group than in the sham group at 6 weeks (p = 0.045). There were no significant differences in the response and remission rates or cognitive measures between the active and sham groups. No serious adverse events were observed in either group.

CONCLUSIONS

These results suggest that dTMS might be effective and safe in office workers with treatment-resistant depression. Further well-designed studies are needed.

Intermittent Theta-Burst Stimulation Transcranial Magnetic Stimulation Increases GABA in the Medial Prefrontal Cortex: A Preliminary Sham-Controlled Magnetic Resonance Spectroscopy Study in Acute Bipolar Depression

Background: Magnetic resonance spectroscopy (MRS) has been used to identify gamma-aminobutyric acid (GABA) alterations in mood disorders, particularly in the medial prefrontal cortex (mPFC) where decreased concentrations have been associated with anhedonia. In major depressive disorder (MDD), prior work suggests that repetitive transcranial magnetic stimulation (rTMS) increases mPFC GABA concentrations proportional to antidepressant response. To our knowledge, this has not been examined in acute bipolar depression. Methods: As part of a multicentre 4-week randomized, double-blind, sham-controlled trial using intermittent theta-burst stimulation (iTBS) of the left dorsolateral prefrontal cortex (DLPFC) in individuals with acute bipolar depression, we quantified mPFC GABA and Glx (glutamate+glutamine) concentrations using a 3T MRS scan at baseline and after the intervention. Depressive symptoms were measured using the Montgomery-Asberg Depression Rating Scale (MADRS) and the Hamilton Depression Rating Scale-17 (HRDS-17), and anhedonia was measured using the Snaith-Hamilton Pleasure Scale (SHAPS). Results: The trial was terminated for futility and magnetic resonance spectroscopy data was acquired for 18 participants. At baseline, there were no associations between GABA or Glx concentrations and anhedonia, however GABA was negative correlated with depressive symptom severity on the HRDS-17. Compared to the sham-iTBS group, participants receiving active-iTBS had a significant increase in mPFC GABA concentrations. This was unrelated to antidepressant outcomes or improvements in anhedonia. Conclusion: Our data suggests that iTBS targeting the DLPFC is associated with physiological changes in the mPFC. In acute bipolar depression, our preliminary data suggests that mPFC GABA is dissociated from antidepressant iTBS treatment outcomes and anhedonia.

Current clinical practice of electroconvulsive therapy and repetitive transcranial magnetic stimulation in psychiatry, a German sample

The purpose of the study was to evaluate the current clinical practice of Electroconvulsive Therapy and Repetitive Transcranial Magnetic Stimulation in German psychiatry. Case-based data (> 1.000.000 cases) were collected according to §21 of the German hospital remuneration law from January 2015 to December 2017. The study cohort comprises approximately 35-40% of the annual psychiatric cases and hospitals in Germany. Frequency of ECT and rTMS cases were investigated considering main diagnoses according to ICD-10 and treatment settings (inpatient vs. day-care). ECT cases with short-term hospitalization (≤ 4 days) were supposed to be maintenance ECT cases. A linear regression analysis was conducted to estimate trends in the use of ECT and rTMS. Different groups were compared using Chi-square tests. ECT and rTMS cases appear to increase in total during the observation period possibly due to facilities newly introducing ECT and rTMS but also to increased frequency of treatments. Both treatments were rarely performed in day-care settings (0.89% and 11.25%). ECT was performed in 1.72% of all cases with affective disorders and in 1.48% with major depressions, respectively. Age ≥ 65 years, females, severe and psychotic depression were significantly associated with a higher rate of ECT cases. > 40% of all ECT cases were possibly maintenance ECT cases. Only 0.60% of these were performed in day- care settings. rTMS was primarily performed in major depression (86,7% of all rTMS cases). This study suggests a growing demand for ECT and rTMS. Nevertheless, the use of ECT is still low compared to the high prevalence of treatment resistant depression. The use of rTMS is even lower and seems to be restricted to specialized institutions. Maintenance ECT is frequently carried out in an inpatient setting. Limitations of this study are the case- and group-based analysis, missing data on outpatient services and treatment sessions per case. Therefore, the database is not necessarily representative for the entire German healthcare system. Further studies are needed to verify the presented findings and should address the feasibility of ambulatory and day-care ECT services.

Magnetic brain stimulation using iron oxide nanoparticle-mediated selective treatment of the left prelimbic cortex as a novel strategy to rapidly improve depressive-like symptoms in mice

Magnetic brain stimulation has greatly contributed to the advancement of neuroscience. However, challenges remain in the power of penetration and precision of magnetic stimulation, especially in small animals. Here, a novel combined magnetic stimulation system (c-MSS) was established for brain stimulation in mice. The c-MSS uses a mild magnetic pulse sequence and injection of superparamagnetic iron oxide (SPIO) nanodrugs to elevate local cortical susceptibility. After imaging of the SPIO nanoparticles in the left prelimbic (PrL) cortex in mice, we determined their safety and physical characteristics. Depressive-like behavior was established in mice using a chronic unpredictable mild stress (CUMS) model. SPIO nanodrugs were then delivered precisely to the left PrL cortex using in situ injection. A 0.1 T magnetic field (adjustable frequency) was used for magnetic stimulation (5 min/session, two sessions daily). Biomarkers representing therapeutic effects were measured before and after c-MSS intervention. Results showed that c-MSS rapidly improved depressive-like symptoms in CUMS mice after stimulation with a 10 Hz field for 5 d, combined with increased brain-derived neurotrophic factor (BDNF) and inactivation of hypothalamic-pituitary-adrenal (HPA) axis function, which enhanced neuronal activity due to SPIO nanoparticle-mediated effects. The c-MSS was safe and effective, representing a novel approach in the selective stimulation of arbitrary cortical targets in small animals, playing a bioelectric role in neural circuit regulation, including antidepressant effects in CUMS mice. This expands the potential applications of magnetic stimulation and progresses brain research towards clinical application.

A retrospective analysis of bipolar depression treated with transcranial magnetic stimulation

INTRODUCTION

Treatment options are limited for patients with bipolar depression. Antidepressants added to mood stabilizers even carry risks of precipitating mixed/manic episodes. Transcranial magnetic stimulation (TMS) may provide a safe and effective option for these patients.

METHODS

Database analysis of the TMS Service at Sheppard Pratt Health System identified patients with bipolar disorder type I (BD1) or II (BD2) in a pure depressive phase at initiation of TMS. Records were reviewed for response and remission rates based on MADRS scores, time to effect, and adverse events, notably treatment-emergent affective switching. All had failed at least two prior treatments for depression, were currently on at least one mood stabilizer and off antidepressants. Stimulation parameters targeted left dorsolateral prefrontal cortex: 120% motor threshold, 10 pulses per second (pps) × 4s, intertrain interval (ITI) 26s, 75 trains (37.5 min/session) for 3,000 pps total, 5 sessions/week for 30 total treatments, or until remission criteria were met.

RESULTS

A total of 44 patients with BD were identified, representing 15% of the total TMS population. 77% of those who completed a course of TMS met response criteria, and 41% of subjects who completed at least 25 treatments met remission criteria. Subjects with BD1 were more likely to respond, remit, or suffer an adverse event than those with BD2. No patient met clinical criteria for a manic/mixed episode, but four (10%) discontinued due to concerns of activation.

CONCLUSIONS

TMS is effective in the bipolar depressed population where episode focused intervention can be specifically offered. Risk of psychomotor agitation must be closely monitored.

A Systematic Review and Meta-Analysis of Randomized Sham-Controlled Trials of Repetitive Transcranial Magnetic Stimulation for Bipolar Disorder

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) is effective in treating unipolar depression. However, the efficacy of rTMS in bipolar disorder (BD) is unclear. This meta-analysis aimed to examine the efficacy and tolerability of rTMS for both depressive and manic phases in BD.

METHODS

MEDLINE, EMBASE, PsycINFO, CENTRAL databases were searched for controlled trials on treatment of BD with rTMS. Primary outcomes included changes in depression or mania scores, response and remission rates. Secondary outcomes included quality of life and functioning assessment. We used random-effects model, Hedge's g, risk differences (RDs) and the number needed to treat (NNT).

RESULTS

Eleven randomized sham-controlled studies were included, with a total of 345 patients with BD (bipolar depression = 257, mania = 86, mixed affective = 2). Trials of rTMS in bipolar depression (N = 8) demonstrated small but significant improvement in depression scores [standardized mean difference = 0.302, p < 0.05], compared to control group. Furthermore, rTMS brought a higher remission rate than sham-controls [RD = 0.104 ± 0.044, p < 0.05, NNT = 10; and a trend of greater response rate [RD = 0.074 ± 0.039, p = 0.06]. Results were inconclusive for effect of rTMS in mania. In both depressive and manic groups, no serious adverse events were reported. Risk of treatment-emergent mania appeared low.

LIMITATIONS

There was limited number of eligible primary studies, with variable randomization procedures.

CONCLUSION

rTMS appears safe and effective in treating bipolar depression. More stringent RCTs are necessary for concrete conclusion about efficacy in mania.

Repetitive Transcranial Magnetic Stimulation in the Treatment of Bipolar Disorder

Bipolar disorder (BD) is a debilitating mood disorder marked by manic, hypomanic and/or mixed or depressive episodes. It affects approximately 1-2% of the population and is linked to high rates of suicide, functional impairment and poorer quality of life. Presently, treatment options for BD are limited. There is a strong evidence base for pharmacological (e.g., lithium) and psychological (e.g., psychoeducation) treatments; however, both of these pose challenges for treatment outcomes (e.g., non-response, side-effects, limited access). Repetitive transcranial magnetic stimulation (rTMS), a non-invasive brain stimulation technique, is a recommended treatment for unipolar depression, but it is unclear whether rTMS is an effective, safe and well tolerated treatment in people with BD. This article reviews the extant literature on the use of rTMS to treat BD across different mood states. We found 34 studies in total (N = 611 patients), with most assessing bipolar depression (n = 26), versus bipolar mania (n = 5), mixed state bipolar (n = 2) or those not in a current affective episode (n = 1). Across all studies, there appears to be a detectable signal of efficacy for rTMS treatment, as most studies report that rTMS treatment reduced bipolar symptoms. Importantly, within the randomised controlled trial (RCT) study designs, most reported that rTMS was not superior to sham in the treatment of bipolar depression. However, these RCTs are based on small samples (NBD ⩽ 52). Reported side effects of rTMS in BD include headache, dizziness and sleep problems. Ten studies (N = 14 patients) reported cases of affective switching; however, no clear pattern of potential risk factors for affective switching emerged. Future adequately powered, sham-controlled trials are needed to establish the ideal rTMS treatment parameters to help better determine the efficacy of rTMS for the treatment of BD.

An update on the clinical use of repetitive transcranial magnetic stimulation in the treatment of depression

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) is an increasingly used treatment for patients with depression. The use of rTMS in depression is supported by over 20 years of clinical trials. There has been a significant increase in knowledge around the use of rTMS in recent years.

OBJECTIVE

The aim of this paper was to review the use of rTMS in depression to provide an update for rTMS practitioners and clinicians interested in the clinical use of this treatment.

METHODS

A targeted review of the literature around the use of rTMS treatment of depression with a specific focus on studies published in the last 3 years.

RESULTS

High-frequency rTMS applied to the left dorsolateral prefrontal cortex is an effective treatment for acute episodes of major depressive disorder. There are several additional methods of rTMS delivery that are supported by clinical trials and meta-analyses but no substantive evidence that any one approach is any more effective than any other. rTMS is effective in unipolar depression and most likely bipolar depression. rTMS courses may be repeated in the management of depressive relapse but there is less evidence for the use of rTMS in the maintenance phase.

CONCLUSIONS

The science around the use of rTMS is rapidly evolving and there is a considerable need for practitioners to remain abreast of the current state of this literature and its implications for clinical practice. rTMS is an effective antidepressant treatment but its optimal use should be continually informed by knowledge of the state of the art.

The CINP Guidelines on the Definition and Evidence-Based Interventions for Treatment-Resistant Bipolar Disorder

BACKGROUND

Resistant bipolar disorder is a major mental health problem related to significant disability and overall cost. The aim of the current study was to perform a systematic review of the literature concerning (1) the definition of treatment resistance in bipolar disorder, (2) its clinical and (3) neurobiological correlates, and (4) the evidence-based treatment options for treatment-resistant bipolar disorder and for eventually developing guidelines for the treatment of this condition.

MATERIALS AND METHODS

The PRISMA method was used to identify all published papers relevant to the definition of treatment resistance in bipolar disorder and the associated evidence-based treatment options. The MEDLINE was searched to April 22, 2018.

RESULTS

Criteria were developed for the identification of resistance in bipolar disorder concerning all phases. The search of the literature identified all published studies concerning treatment options. The data were classified according to strength, and separate guidelines regarding resistant acute mania, acute bipolar depression, and the maintenance phase were developed.

DISCUSSION

The definition of resistance in bipolar disorder is by itself difficult due to the complexity of the clinical picture, course, and treatment options. The current guidelines are the first, to our knowledge, developed specifically for the treatment of resistant bipolar disorder patients, and they also include an operationalized definition of treatment resistance. They were based on a thorough and deep search of the literature and utilize as much as possible an evidence-based approach.

The Treatment of Bipolar Depression: Current Status and Future Perspectives

Purpose of Review

This paper aims to review current available treatment options and to consider future directions in the treatment of bipolar depression.

Recent Findings

There are a limited number of established treatments that have demonstrated varied efficacy in acute bipolar depression including modern antipsychotics (quetiapine, lurasidone, olanzapine ± fluoxetine and recently cariprazine) and mood stabilisers (lamotrigine and valproate). Lithium has a role in protecting against depressive relapses and suicide. Alternative and experimental treatments including pramipexole, modafinil/armodafinil, omega-3 fatty acids and thyroxine may be used to augment the treatment of bipolar depression. Ketamine represents a major breakthrough, producing rapid reductions in depressive symptoms even in cases of treatment-resistance, but challenges remain in how best to maintain response and reduce unwanted side effects.

Summary

There remains uncertainty with regard to the relative efficacy and safety of established and experimental treatments for bipolar depression. Further work using consistent, optimal trial designs as well as further investigation into novel compounds and treatment interventions is warranted.

Repetitive Transcranial Magnetic Stimulation in the Treatment of Bipolar Depression: Experience From a Clinical Setting

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive Food and Drug Administration (FDA)-approved treatment for unipolar treatment-resistant depression (TRD). rTMS has been utilized clinically to treat bipolar TRD; however, there remains a lack of evidence and support for effectively utilizing this intervention for bipolar TRD. We retrospectively analyzed data from a group of patients who were treated with rTMS for unipolar or bipolar TRD and describe a case example to further delineate management techniques for employing rTMS in the treatment of bipolar TRD.

METHODS

Records of 71 patients treated with rTMS for unipolar (n=54) or bipolar (n=17) TRD between 2008 and 2017 were reviewed. The primary outcome of depression severity, the Quick Inventory of Depressive Symptomatology, was completed at baseline and after every 5 sessions throughout the course of 30 treatments. Secondary outcomes involved a comparison of outcomes and clinical characteristics within and between the bipolar and unipolar TRD groups.

RESULTS

In the total sample, patients' depression improved significantly over the course of treatment. Patients with bipolar TRD showed greater response and remission rates over the course of treatment compared with patients with unipolar TRD, but this difference was not statistically significant. Both groups showed a similar pattern of depression response over treatment time. No manic or hypomanic episodes occurred during any patient's course of rTMS treatment. A case example is provided discussing the timing of rTMS in a patient with bipolar depression to decrease the likelihood of treatment-induced hypomania.

LIMITATIONS

Limitations included the small overall sample size, the smaller size of the patient group with bipolar TRD compared with the group with unipolar TRD, and the naturalistic setting of this study.

CONCLUSIONS

Our data suggest that rTMS may be equally effective and safe for patients with both unipolar and bipolar depression. Patients with bipolar TRD showed a similar response profile over treatment time compared with patients with unipolar TRD.

Twice-daily neuronavigated intermittent theta burst stimulation for bipolar depression: A Randomized Sham-Controlled Pilot Study

The safety and efficacy of neuronavigated intermittent theta burst stimulation (iTBS) in patients with bipolar depression has not yet been investigated. We hypothesized the superiority of active iTBS over sham. Twenty-six patients were randomly allocated to receive either active (n=12) or sham (n=14) iTBS. Response and remission rates according to changes in depression MADRS score were high following active iTBS (72% and 42% for response and remission rates, respectively), but no significant difference was found after sham stimulation (42%and 25%). No adverse events were observed. This study revealed the safety and tolerability of twice daily iTBS in patients with bipolar depression. Larger controlled studies are warranted to prove iTBS superiority in treatment-resistant bipolar depression.

Beyond evidence-based treatment of bipolar disorder: Rational pragmatic approaches to management

The evidence for efficacy of many currently available treatments for bipolar disorder is based on studies of nonrefractory patients with bipolar disorder. Therefore, not surprisingly, most treatment recommendations and guidelines for the treatment of bipolar disorder and its many comorbidities depend heavily on data from placebo controlled randomized clinical trials (RCTs), but these RCTs provide little direction for the clinician as to what next steps might be optimal in non- or partial-responders and in those with ongoing medical and psychiatric comorbidities. Given this and the paucity of RCTs at later treatment junctures, we thought it appropriate to begin a discussion of the quality of the data that some experts in the field might consider using in choosing and sequencing drugs and their combination. We acknowledge that many other clinical investigators may prefer very different sequences, but thought the suggestions offered here might be useful to some clinicians in the field, might start discussions of other options in the literature, and, at the same time, provide a preliminary outline for a new round of much-needed clinical trials to better inform clinical practice. Given the very wide range of the quality of the data and clinical principles on which the current suggestions are based, only minimal references are included and a comprehensive review of the literature supporting each option would be outside the scope of this manuscript.

Noninvasive brain stimulation in psychiatric disorders: a primer

OBJECTIVE

Noninvasive brain stimulation (NIBS) techniques, such as transcranial direct current stimulation (tDCS) and repetitive transcranial magnetic stimulation (rTMS), are increasingly being used to treat mental disorders, particularly major depression. The aim of this comprehensive review is to summarize the main advances, limitations, and perspectives of the field.

METHODS

We searched PubMed and other databases from inception to July 2017 for articles, particularly systematic reviews and meta-analyses, evaluating the use of NIBS in psychiatric disorders.

RESULTS

We reviewed the mechanisms of action, safety, tolerability, efficacy, and relevant clinical parameters of NIBS. Repetitive TMS is already an established technique for the treatment of depression, and there is theoretically room for further methodological development towards a high-end therapeutic intervention. In contrast, tDCS is a technically easier method and therefore potentially suitable for wider clinical use. However the evidence of its antidepressant efficacy is less sound, and a recent study found tDCS to be inferior to antidepressant pharmacotherapy. Clinical trials using rTMS for other mental disorders produced mixed findings, whereas tDCS use has not been sufficiently appraised.

CONCLUSION

The most promising results of NIBS have been obtained for depression. These techniques excel in safety and tolerability, although their efficacy still warrants improvement.

Bilateral Transcranial Magnetic Stimulation on DLPFC Changes Resting State Networks and Cognitive Function in Patients With Bipolar Depression

Introduction: Bipolar patients have abnormalities in cognitive functions and emotional processing. Two resting state networks (RSNs), the default mode network (DMN) and the sensorimotor network (SMN), play a decisive role in these two functions. Dorsolateral prefrontal cortex (DLPFC) is one of the main areas in the central executive network (CEN), which is linked to the activities of each of the two networks. Studies have found DLPFC abnormalities in both hemispheres of patients with bipolar depression. We hypothesized that the bilateral repetitive transcranial magnetic stimulation (rTMS) of DLPFC would produce changes in the activity of both the SMN and DMN as well as relevant cognitive function in patients with bipolar depression that responded to treatment.

Methods: 20 patients with bipolar depression underwent 10 sessions of 1 Hz rTMS on right DLPFC with subsequent 10 Hz rTMS on left DLPFC. Changes in electroencephalography resting networks between pre and post rTMS were evaluated utilizing low-resolution electromagnetic tomography (eLORETA). Depression symptom was assessed using the Beck Depression Inventory (BDI-II) and cognitive function was assessed by Verbal Fluency Test (VFT), Rey Auditory Verbal Learning Test (RAVLT), Stroop Test, and Wisconsin Card Sorting Test (WCST).

Results: Responders to rTMS showed significantly lower DMN activity at baseline and a significant decrease in SMN connectivity after treatment. Non-responders did not significantly differ from the control group at the baseline and they showed higher activity in the SMN, visual network, and visual perception network compared to control group following treatment. Bilateral rTMS resulted in significant changes in the executive functions, verbal memory, and depression symptoms. No significant changes were observed in selective attention and verbal fluency.

Conclusion: Bilateral stimulation of DLPFC, as the main node of CEN, results in changes in the activity of the SMN and consequently improves verbal memory and executive functions in patients with bipolar depression.

Clinical Usefulness of Therapeutic Neuromodulation for Major Depression: A Systematic Meta-Review of Recent Meta-Analyses

The authors conducted a meta-review of meta-analyses published in the past decade on therapeutic neuromodulation (ie, repetitive transcranial magnetic stimulation, transcranial direct current stimulation, vagus nerve stimulation and deep brain stimulation) for major depression. Active repetitive transcranial magnetic stimulation and transcranial direct current stimulation have been generally associated with small to moderate effect sizes vis-à-vis their efficacy and with similar acceptability compared with sham. Vagus nerve stimulation and deep brain stimulation (although more challenging to investigate) have demonstrated preliminary effectiveness, particularly during longer-term follow-up.

Clinical Repetitive Transcranial Magnetic Stimulation for Posttraumatic Stress Disorder, Generalized Anxiety Disorder, and Bipolar Disorder

Repetitive transcranial magnetic stimulation (rTMS) is being investigated for psychiatric disorders such as posttraumatic stress disorder (PTSD), generalized anxiety disorder (GAD), and both phases of bipolar disorder. Case series, open trials, and randomized controlled studies have demonstrated preliminary support for treating PTSD with rTMS alone as well as with rTMS combined with psychotherapy. Similarly, there is some evidence that GAD can be treated with rTMS. The results for treating either phase of bipolar disorder are mixed with most of the current studies showing lack of benefit over sham. Further study is required before rTMS can be recommended for these disorders.