Different dorsolateral prefrontal activation during an emotionalautobiographical memory task between male and female depressed individuals: a fNIRS study

Depression in male and female are commonly associated with different prevalence, severity, and, in some cases, distinct syndromes or subtypes. However, only a small amount of research has been conducted to completely understand the underlying neuroanatomical mechanisms. The goal of the current study was to provide neural markers for specific depression therapies by demonstrating the differences in aberrant prefrontal activity between male and female depressed subjects during an emotional autobiographical memory test. The study included 127 young adults who were randomly assigned to one of two groups: male depression (62 participants) or female depression (65 participants). The average oxyhemoglobin levels in the dorsolateral prefrontal cortex throughout the emotional autobiographical memory task were assessed utilizing 53-channel functional near-infrared spectroscopy imaging equipment. The oxy-Hb activation in the left dorsolateral prefrontal cortex (lDLPFC) and right dorsolateral prefrontal cortex (rDLPFC) had no significant interaction between groups and emotional valences. A significant main effect was found between male and female, with female depression groups showing lower oxy-Hb activity in lDLPFC and rDLPFC than male depression groups. Male and female depression patients showed distinct brain activation in the DLPFC during an emotional autobiographical memory test, suggesting potential specific neurological indicators for varied somatic symptoms in male and female depression patients. These distinctions should be taken into account while creating preventive measures.

A multi-center, randomized, double-blind, sham-stimulation controlled study of transcranial magnetic stimulation with precision navigation for the treatment of multiple system atrophy

BACKGROUND

Multiple system atrophy (MSA) is recognized as an atypical Parkinsonian syndrome, distinguished by a more rapid progression than that observed in Parkinson's disease. Unfortunately, the prognosis for MSA remains poor, with a notable absence of globally recognized effective treatments. Although preliminary studies suggest that transcranial magnetic stimulation (TMS) could potentially alleviate clinical symptoms in MSA patients, there is a significant gap in the literature regarding the optimal stimulation parameters. Furthermore, the field lacks consensus due to the paucity of robust, large-scale, multicenter trials.

METHODS

This investigation is a multi-center, randomized, double-blind, sham-controlled trial. We aim to enroll 96 individuals diagnosed with MSA, categorized into Parkinsonian type (MSA-P) and cerebellar type (MSA-C) according to their predominant clinical features. Participants will be randomly allocated in a 1:1 ratio to either the TMS or sham stimulation group. Utilizing advanced navigation techniques, we will ensure precise targeting for the intervention, applying theta burst stimulation (TBS). To assess the efficacy of TBS on both motor and non-motor functions, a comprehensive evaluation will be conducted using internationally recognized clinical scales and gait analysis. To objectively assess changes in brain connectivity, functional magnetic resonance imaging (fMRI) and electroencephalography (EEG) will be employed as sensitive indicators before and after the intervention.

DISCUSSION

The primary aim of this study is to ascertain whether TBS can alleviate both motor and non-motor symptoms in patients with MSA. Additionally, a critical component of our research involves elucidating the underlying mechanisms through which TBS exerts its potential therapeutic effects.

ETHICS AND DISSEMINATION

All study protocols have been reviewed and approved by the First Affiliated Medical Ethics Committee of the Air Force Military Medical University (KY20232118-F-1).

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR2300072658. Registered on 20 June 2023.

Differential analgesic effects of high-frequency or accelerated intermittent theta burst stimulation of M1 on experimental tonic pain: Correlations with cortical activity changes assessed by TMS-EEG

Accelerated intermittent theta burst stimulation (AiTBS) has attracted much attention in the past few years as a new form of brain stimulation paradigm. However, it is unclear the relative efficacy of AiTBS on cortical excitability compared to conventional high-frequency rTMS. Using concurrent TMS and electroencephalogram (TMS-EEG), this study systematically compared the efficacy on cortical excitability and a typical clinical application (i.e. pain), between AiTBS with different intersession interval (ISIs) and 10-Hz rTMS. Participants received 10-Hz rTMS, AiTBS-15 (3 iTBS sessions with a 15-min ISI), AiTBS-50 (3 iTBS sessions with a 50-min ISI), or Sham stimulation over the primary motor cortex on four separate days. All four protocols included a total of 1800 pulses but with different session durations (10-Hz rTMS ​= ​18, AiTBS-15 ​= ​40, and AiTBS-50 ​= ​110 ​min). AiTBS-50 and 10-Hz rTMS were more effective in pain reduction compared to AiTBS-15. Using single-pulse TMS-induced oscillation, our data revealed low gamma oscillation as a shared cortical excitability change across all three active rTMS protocols but demonstrated completely opposite directions. Changes in low gamma oscillation were further associated with changes in pain perception across the three active conditions. In contrast, a distinct pattern of TMS-evoked potentials (TEPs) was revealed, with 10-Hz rTMS decreasing inhibitory N100 amplitude and AiTBS-15 reducing excitatory P60 amplitude. These changes in TEPs were also covarying with low gamma power changes. Sham stimulation indicated no significant effect on either cortical excitability or pain perception. These results are relevant only for provoked experimental pain, without being predictive for chronic pain, and revealed a change in low gamma oscillation, particularly around the very particular frequency of 40 ​Hz, shared between AiTBS and high-frequency rTMS. Conversely, cortical excitability (balance between excitation and inhibition) assessed by TEP recording was modulated differently by AiTBS and high-frequency rTMS paradigms.

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.

Intermittent theta-burst stimulation alleviates hypoxia-ischemia-caused myelin damage and neurologic disability

Neonatal hypoxia-ischemia (HI) results in behavioral deficits, characterized by neuronal injury and retarded myelin formation. To date, limited treatment methods are available to prevent or alleviate neurologic sequelae of HI. Intermittent theta-burst stimulation (iTBS), a non-invasive therapeutic procedure, is considered a promising therapeutic tool for treating some neurocognitive disorders and neuropsychiatric diseases. Hence, this study aims to investigate whether iTBS can prevent the negative behavioral manifestations of HI and explore the mechanisms for associations. We exposed postnatal day 10 Sprague-Dawley male and female rats to 2 h of hypoxia (6% O2) following right common carotid artery ligation, resulting in oligodendrocyte (OL) dysfunction, including reduced proliferation and differentiation of oligodendrocyte precursor cells (OPCs), decreased OL survival, and compromised myelin in the corpus callosum (CC) and hippocampal dentate gyrus (DG). These alterations were concomitant with cognitive dysfunction and depression-like behaviors. Crucially, early iTBS treatment (15 G, 190 s, seven days, initiated one day post-HI) significantly alleviated HI-caused myelin damage and mitigated the neurologic sequelae both in male and female rats. However, the late iTBS treatment (initiated 18 days after HI insult) could not significantly impact these behavioral deficits. In summary, our findings support that early iTBS treatment may be a promising strategy to improve HI-induced neurologic disability. The underlying mechanisms of iTBS treatment are associated with promoting the differentiation of OPCs and alleviating myelin damage.

Increased anti-correlation between the left dorsolateral prefrontal cortex and the default mode network following Stanford Neuromodulation Therapy (SNT): analysis of a double-blinded, randomized, sham-controlled trial

SNT is a high-dose accelerated intermittent theta-burst stimulation (iTBS) protocol coupled with functional-connectivity-guided targeting that is an efficacious and rapid-acting therapy for treatment-resistant depression (TRD). We used resting-state functional MRI (fMRI) data from a double-blinded sham-controlled randomized controlled trial1 to reveal the neural correlates of SNT-based symptom improvement. Neurobehavioral data were acquired at baseline, post-treatment, and 1-month follow-up. Our primary analytic objective was to investigate changes in seed-based functional connectivity (FC) following SNT and hypothesized that FC changes between the treatment target and the sgACC, DMN, and CEN would ensue following active SNT but not sham. We also investigated the durability of post-treatment observed FC changes at a 1-month follow-up. Study participants included transcranial magnetic stimulation (TMS)-naive adults with a primary diagnosis of moderate-to-severe TRD. Fifty-four participants were screened, 32 were randomized, and 29 received active or sham SNT. An additional 5 participants were excluded due to imaging artifacts, resulting in 12 participants per group (Sham: 5F; SNT: 5F). Although we did not observe any significant group × time effects on the FC between the individualized stimulation target (L-DLPFC) and the CEN or sgACC, we report an increased magnitude of negative FC between the target site and the DMN post-treatment in the active as compared to sham SNT group. This change in FC was sustained at the 1-month follow-up. Further, the degree of change in FC was correlated with improvements in depressive symptoms. Our results provide initial evidence for the putative changes in the functional organization of the brain post-SNT.

Frontal Theta Asymmetry may be a new target for reducing the severity of depression and improving cognitive function in depressed patients

BACKGROUND

The prevalence of depressive disorder is increasing due to a variety of factors, which brings a huge strain on individuals, families and society. This study aims to investigate whether there is Frontal Theta Asymmetry (FTA) in depressed patients, and whether FTAs are related to depression severity and cognitive function changes in depressed patients.

METHODS

Participants who met the inclusion criteria were enrolled in this study. Socio-demographic data of each participant were recorded. Zung's self-rating Depression Scale was used to assess the depression status of participants. P300 was used to evaluate the cognitive function of participants. EEG data from participants were collected by the NeuroScan SynAmps RT EEG system. t-test, Wilcoxon rank-sum test and Chi-square test were used to detect the differences of different variables between the two groups. Multiple linear regression analysis and multiple logistic regression analysis were used to analyze relationships between FTAs in different regions and participants' depression status and cognitive function.

RESULTS

A total of 66 depressed participants and 47 healthy control participants were included in this study. The theta spectral power of the left frontal lobe was slightly stronger than that of the right frontal lobe in the depression group, while the opposite was true in the healthy control group. The FTA in F3/F4 had certain effects on the emergence of depression in participants, the emergence of depression in participants and Changes in cognitive function.

CONCLUSIONS

FTAs are helpful to assess the severity of depression and early identify cognitive impairment in patients with depression.

Comparisons of Accelerated Continuous and Intermittent Theta Burst Stimulation for Treatment-Resistant Depression and Suicidal Ideation

BACKGROUND

Suicidal ideation is a substantial clinical challenge in treatment-resistant depression (TRD). Recent work demonstrated promising antidepressant effects in TRD patients with no or mild suicidal ideation using a specific protocol termed intermittent theta burst stimulation (iTBS). Here, we examined the clinical effects of accelerated schedules of iTBS and continuous TBS (cTBS) in patients with moderate to severe suicidal ideation.

METHODS

Patients with TRD and moderate to severe suicidal ideation (n = 44) were randomly assigned to receive accelerated iTBS or cTBS treatment. Treatments were delivered in 10 daily TBS sessions (1800 pulses/session) for 5 consecutive days (total of 90,000 pulses). Neuronavigation was employed to target accelerated iTBS and cTBS to the left and right dorsolateral prefrontal cortex (DLPFC), respectively. Clinical outcomes were evaluated in a 4-week follow-up period.

RESULTS

Accelerated cTBS was superior to iTBS in the management of suicidal ideation (pweek 1 = .027) and anxiety symptoms (pweek 1 = .01). Accelerated iTBS and cTBS were comparable in antidepressant effects (p < .001; accelerated cTBS: mean change at weeks 1, 3, 5 = 49.55%, 54.99%, 53.11%; accelerated iTBS: mean change at weeks 1, 3, 5 = 44.52%, 48.04%, 51.74%). No serious adverse events occurred during the trial. One patient withdrew due to hypomania. The most common adverse event was discomfort at the treatment site (22.73% in both groups).

CONCLUSIONS

These findings provide the first evidence that accelerated schedules of left DLPFC iTBS and right DLPFC cTBS are comparably effective in managing antidepressant symptoms and indicate that right DLPFC cTBS is potentially superior in reducing suicidal ideation and anxiety symptoms.

Prolonged intermittent theta burst stimulation for post-stroke aphasia: protocol of a randomized, double-blinded, sham-controlled trial

Background

Post-stroke aphasia (PSA) is one of the most devastating symptoms after stroke, yet limited treatment options are available. Prolonged intermittent theta burst stimulation (piTBS) is a promising therapy for PSA. However, its efficacy remains unclear. Therefore, we aim to investigate the efficacy of piTBS over the left supplementary motor area (SMA) in improving language function for PSA patients and further explore the mechanism of language recovery.

Methods

This is a randomized, double-blinded, sham-controlled trial. A total of 30 PSA patients will be randomly allocated to receive either piTBS stimulation or sham stimulation for 15 sessions over a period of 3 weeks. The primary outcome is the Western Aphasia Battery Revised (WAB-R) changes after treatment. The secondary outcomes include The Stroke and Aphasia Quality of Life Scale (SAQOL-39 g), resting-state electroencephalogram (resting-state EEG), Event-related potentials (ERP), brain derived neurotrophic factor (BDNF). These outcome measures are assessed before treatment, after treatment, and at 4-weeks follow up. This study was registered in Chinese Clinical Trial Registry (No. ChiCTR23000203238).

Discussion

This study protocol is promising for improving language in PSA patients. Resting-state EEG, ERP, and blood examination can be used to explore the neural mechanisms of PSA treatment with piTBS.

Clinical trial registration

https://www.chictr.org.cn/index.html, ChiCTR2300074533.

Single session of intermittent theta burst stimulation alters brain activity of patients in vegetative state

BACKGROUND

Non-invasive brain stimulation is considered as a promising technology for treating patients with disorders of consciousness (DOC). Various approaches and protocols have been proposed; however, few of them have shown potential effects on patients with vegetative state (VS). This study aimed to explore the neuro-modulation effects of intermittent theta burst stimulation (iTBS) on the brains of patients with VS and to provide a pilot investigation into its possible role in treating such patients.

METHODS

We conducted a sham-controlled crossover study, a real and a sham session of iTBS were delivered over the left dorsolateral prefrontal cortex of such patients. A measurement of an electroencephalography (EEG) and a behavioral assessment of the Coma Recovery Scale-Revised (CRS-R) were applied to evaluate the modulation effects of iTBS before and after stimulation.

RESULTS

No meaningful changes of CRS-R were found. The iTBS altered the spectrum, complexity and functional connectivity of the patients. The real stimulation induced a trend of decreasing of delta power at T1 and T2 in the frontal region, significant increasing of permutation entropy at the T2 in the left frontal region. In addition, brain functional connectivity, particularly inter-hemispheric connectivity, was strengthened between the electrodes of the frontal region. The sham stimulation, however, did not induce any significant changes of the brain activity.

CONCLUSIONS

One session of iTBS significantly altered the oscillation power, complexity and functional connectivity of brain activity of VS patients. It may be a valuable tool on modulating the brain activities of patients with VS.

Theta-burst rTMS in schizophrenia to ameliorate negative and cognitive symptoms: study protocol for a double-blind, sham-controlled, randomized clinical trial

BACKGROUND

Treatment effects of conventional approaches with antipsychotics or psychosocial interventions are limited when it comes to reducing negative and cognitive symptoms in schizophrenia. While there is emerging clinical evidence that new, augmented protocols based on theta-burst stimulation can increase rTMS efficacy dramatically in depression, data on similar augmented therapies are limited in schizophrenia. The different patterns of network impairments in subjects may underlie that some but not all patients responded to given stimulation locations.

METHODS

Therefore, we propose an augmented theta-burst stimulation protocol in schizophrenia by stimulating both locations connected to negative symptoms: (1) the left dorsolateral prefrontal cortex (DLPFC), and (2) the vermis of the cerebellum. Ninety subjects with schizophrenia presenting negative symptoms and aging between 18 and 55 years will be randomized to active and sham stimulation in a 1:1 ratio. The TBS parameters we adopted follow the standard TBS protocols, with 3-pulse 50-Hz bursts given every 200 ms (at 5 Hz) and an intensity of 100% active motor threshold. We plan to deliver 1800 stimuli to the left DLPFC and 1800 stimuli to the vermis daily in two 9.5-min blocks for 4 weeks. The primary endpoint is the change in negative symptom severity measured by the Positive and Negative Syndrome Scale (PANSS). Secondary efficacy endpoints are changes in cognitive flexibility, executive functioning, short-term memory, social cognition, and facial emotion recognition. The difference between study groups will be analyzed by a linear mixed model analysis with the difference relative to baseline in efficacy variables as the dependent variable and treatment group, visit, and treatment-by-visit interaction as independent variables. The safety outcome is the number of serious adverse events.

DISCUSSION

This is a double-blind, sham-controlled, randomized medical device study to assess the efficacy and safety of an augmented theta-burst rTMS treatment in schizophrenia. We hypothesize that social cognition and negative symptoms of patients on active therapy will improve significantly compared to patients on sham treatment.

TRIAL REGISTRATION

The study protocol is registered at "ClinicalTrials.gov" with the following ID: NCT05100888. All items from the World Health Organization Trial Registration Data Set are registered. Initial release: 10/19/2021.

Accelerated sequential bilateral theta-burst stimulation in major depression: an open trial

Theta burst stimulation (TBS) is approved and widely used in the treatment of treatment resistant-major depression. More recently, accelerated protocols delivering multiple treatments per day have been shown to be efficacious and potentially enhance outcomes compared to once daily protocols. Meanwhile, bilateral treatment protocols have also been increasingly tested to enhance outcomes. Here, we examined the efficacy and safety of accelerated bilateral TBS in major depressive disorder (MDD). In this open label pilot study, 25 patients with MDD (60%: women; mean age (SD): 45.24 (12.22)) resistant to at least one antidepressant, received bilateral TBS, consisting of 5 sequential bilateral intermittent TBS (iTBS) (600 pulses) and continuous TBS (cTBS) (600 pulses) treatments delivered to the left and right dorsolateral prefrontal cortex (DLPFC), respectively, daily for 5 days at 120% resting motor threshold. Outcome measures were post-treat treatment changes at day 5 and 2-weeks in Hamilton Depression Rating Scale (HDRS-17) scores and response (≥ 50% reduction from the baseline scores) and remission (≤ 7) rates. There was a significant reduction in HDRS scores at day 5 (p < 0.001) and 2-weeks post treatment (p < 0.001). The response rates increased from 20% at day 5 to 32% at 2-weeks post treatment suggesting delayed clinical effects. However, reduction in symptom scores between two post treatment endpoints was non-significant. 60% of patients could not tolerate the high intensity stimulation. No major adverse events occurred. Open label uncontrolled study with small sample size. These preliminary findings suggest that accelerated bilateral TBS may be clinically effective and safe for treatment resistant depression. Randomized sham-controlled trials are needed to establish the therapeutic role of accelerated bilateral TBS in depression.Trial registration: ClinicalTrials.gov, NCT10001858.

Efficacy and safety of intermittent theta burst stimulation on adolescents and young adults with major depressive disorder: A randomized, double blinded, controlled trial

BACKGROUND

Intermittent theta burst stimulation (iTBS) is a newer form of Repetitive Transcranial Magnetic Stimulation (rTMS) for depression. However, its efficacy and safety in adolescents and young adults with major depressive disorder (AYA-MDD) have not been well studied, especially when applied with a strategy that combines neuronavigation targeting and accelerated iTBS.

METHODS

In this study, ninety patients were randomly assigned to twice-daily (two 600-pulse sessions spaced out by 10 min, n = 31), once-daily (one 600-pulse session, n = 29) or sham iTBS (no pulses, n = 30) groups for 10 treatment days. The primary outcome measure was the change in depression scores on the Hamilton Rating Scale for Depression (HAMD-17). Other clinical symptoms, such as anxiety, were also evaluated.

RESULTS

Linear mixed model analysis found that scores on the HAMD-17 and its factors improved in all three groups, but these improvements did not significantly differ among groups. Other clinical symptoms such as anxiety also improved. Response and remission rates were relatively low and did not differ among groups at any time point. The most common adverse event was headache, and the proportion of participants who reported headache in the twice-daily and once-daily groups was significantly higher than that in the sham group.

CONCLUSIONS

The current results indicated that twice-daily and once-daily iTBS under neuronavigation are safe and well tolerated in AYA-MDD, but the overall efficacy was not superior to that of sham treatment. We speculated several possible reasons such as the high placebo response of the young population, inadequate iTBS pulses and so on.

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.

Cognitive Effects Following Offline High-Frequency Repetitive Transcranial Magnetic Stimulation (HF-rTMS) in Healthy Populations: A Systematic Review and Meta-Analysis

High-frequency repetitive transcranial magnetic stimulation (HF-rTMS) is a commonly used form of rTMS to treat neuropsychiatric disorders. Emerging evidence suggests that 'offline' HF-rTMS may have cognitive enhancing effects, although the magnitude and moderators of these effects remain unclear. We conducted a systematic review and meta-analysis to clarify the cognitive effects of offline HF-rTMS in healthy individuals. A literature search for randomised controlled trials with cognitive outcomes for pre and post offline HF-rTMS was performed across five databases up until March 2022. This study was registered on the PROSPERO international prospective protocol for systematic reviews (PROSPERO 2020 CRD 42,020,191,269). The Risk of Bias 2 tool was used to assess the risk of bias in randomised trials. Separate analyses examined the cognitive effects of excitatory and inhibitory forms of offline HF-rTMS on accuracy and reaction times across six cognitive domains. Fifty-three studies (N = 1507) met inclusion criteria. Excitatory offline HF-rTMS showed significant small sized effects for improving accuracy (k = 46, g = 0.12) and reaction time (k = 44, g = -0.13) across all cognitive domains collapsed. Excitatory offline HF-rTMS demonstrated a relatively greater effect for executive functioning in accuracy (k = 24, g = 0.14). Reaction times were also improved for the executive function (k = 21, g = -0.11) and motor (k = 3, g = -0.22) domains following excitatory offline HF-rTMS. The current review was restricted to healthy individuals and future research is required to examine cognitive enhancement from offline HF-rTMS in clinical cohorts.

Adjunctive continuous theta burst stimulation for major depressive disorder or bipolar depression: A meta-analysis of randomized controlled studies

OBJECTIVES

As a novel type of theta burst stimulation (TBS), continuous TBS (cTBS) has been shown to have mixed therapeutic effects for major depressive disorder (MDD) or bipolar depression (BD). Thus, we performed a meta-analysis of randomized controlled trials (RCTs) of cTBS for treating major depressive episodes in patients with MDD or BD.

METHODS

A systematic search of four major bibliographic databases (PubMed, EMBASE, Cochrane Library, and PsycINFO) was conducted from inception dates to February 3, 2023 to identify eligible studies. The data were analyzed using a random-effects model.

RESULTS

Three RCTs (n = 78, active cTBS = 37 and sham cTBS = 41) were included the meta-analysis. No significant differences were found in terms of change in Hamilton Depression Rating Scale (HAMD) scores (3 RCTs, n = 78, SMD = -0.09, 95 % CI: -0.53 to 0.36; I2 = 0 %; P = 0.71) and study-defined response (2 RCTs, n = 58, 26.7 % versus 21.4 %, RR = 1.20, 95 % CI: 0.48 to 2.96; I2 = 0 %; P = 0.70) between active and sham cTBS groups. Similarly, no group differences were found in the rates of adverse events and discontinuation due to any reason (P > 0.05).

LIMITATIONS

Meta-analysis had small sample sizes and low number of included studies.

CONCLUSIONS

Although cTBS appeared to be a safe and well-tolerated option for treating major depressive episodes in MDD or BD patients, no advantage in treatment effects was found in this meta-analysis. Future large-scale studies are warranted to assess the efficacy of cTBS for MDD or BD patients with a major depressive episode.

Increasing striatal dopamine release through repeated bouts of theta burst transcranial magnetic stimulation of the left dorsolateral prefrontal cortex. A 18F-desmethoxyfallypride positron emission tomography study

Introduction

Transcranial Magnetic Stimulation (TMS) can modulate fronto-striatal connectivity in the human brain. Here Positron Emission Tomography (PET) and neuro-navigated TMS were combined to investigate the dynamics of the fronto-striatal connectivity in the human brain. Employing 18F-DesmethoxyFallypride (DMFP) - a Dopamine receptor-antagonist - the release of endogenous dopamine in the striatum in response to time-spaced repeated bouts of excitatory, intermittent theta burst stimulation (iTBS) of the Left-Dorsolateral Prefrontal Cortex (L-DLPFC) was measured.

Methods

23 healthy participants underwent two PET sessions, each one with four blocks of iTBS separated by 30 minutes: sham (control) and verum (90% of individual resting motor threshold). Receptor Binding Ratios were collected for sham and verum sessions across 37 time frames (about 130 minutes) in striatal sub-regions (Caudate nucleus and Putamen).

Results

Verum iTBS increased the dopamine release in striatal sub-regions, relative to sham iTBS. Dopamine levels in the verum session increased progressively across the time frames until frame number 28 (approximately 85 minutes after the start of the session and after three iTBS bouts) and then essentially remained unchanged until the end of the session.

Conclusion

Results suggest that the short-timed iTBS protocol performed in time-spaced blocks can effectively induce a dynamic dose dependent increase in dopaminergic fronto-striatal connectivity. This scheme could provide an alternative to unpleasant and distressing, long stimulation protocols in experimental and therapeutic settings. Specifically, it was demonstrated that three repeated bouts of iTBS, spaced by short intervals, achieve larger effects than one single stimulation. This finding has implications for the planning of therapeutic interventions, for example, treatment of major depression.

Repetitive Transcranial Magnetic Stimulation (rTMS) in Major Depression

Major depressive disorder (MDD) is a psychiatric disorder with several effective therapeutic approaches, being antidepressants and psychotherapies the first-line treatments. Nonetheless, due to side effects, limited efficacy, and contraindications for these treatments, alternative treatment options are required. Neurostimulation is a non-pharmacological and non-psychotherapeutic approach that has been under study for diverse neuropsychiatric conditions in the form of electrical or magnetic stimulation of the brain. Repetitive transcranial magnetic stimulation (rTMS) is a neurostimulation method designed to generate magnetic fields and deliver magnetic pulses to stimulate the brain cortex. The magnetic pulses produce electrical currents in the brain which are not intense enough to provoke seizures, differentiating this method from other forms of neurostimulation that produce seizures. Although the exact rTMS mechanisms of action are not completely understood, rTMS seems to cause its beneficial effects through changes in neuroplasticity. Devices and protocols for rTMS are still evolving, becoming more efficient over time. There are still some challenges to be addressed, including further refinement of parameters (coil/device type, location, intensity, frequency, number of sessions, and duration of treatment); treatment cost and burden for patients; and treatment resistance. However, the efficacy, tolerability, and safety of some rTMS protocols have been demonstrated in different double-blind sham-controlled randomized controlled trials and meta-analyses for treatment-resistant depression.

Accelerated transcranial magnetic stimulation for major depressive disorder: A quick path to relief?

Transcranial magnetic stimulation (TMS) is a safe, tolerable, and evidence-based intervention for major depressive disorder (MDD). However, even after decades of research, nearly half of the patients with MDD fail to respond to conventional TMS, with responding slowly and requiring daily attendance at the treatment site for 4-6 weeks. To intensify antidepressant efficacy and shorten treatment duration, accelerated TMS protocols, which involve multiple sessions per day over a few days, have been proposed and evaluated for safety and viability. We reviewed and summarized the current knowledge in accelerated TMS, including stimulation parameters, antidepressant efficacy, anti-suicidal efficacy, safety, and adverse effects. Limitations and suggestions for future directions are also addressed, along with a brief discussion on the application of accelerated TMS during the COVID-19 pandemic. This article is categorized under: Neuroscience > Clinical Neuroscience.

Prediction of antidepressant responses to non-invasive brain stimulation using frontal electroencephalogram signals: Cross-dataset comparisons and validation

BACKGROUND

10-Hz repetitive transcranial magnetic stimulation(rTMS) and intermittent theta-burst stimulation(iTBS) over left prefrontal cortex are FDA-approved, effective options for treatment-resistant depression (TRD). Optimal prediction models for iTBS and rTMS remain elusive. Therefore, our primary objective was to compare prediction accuracy between classification by frontal theta activity alone and machine learning(ML) models by linear and non-linear frontal signals. The second objective was to study an optimal ML model for predicting responses to rTMS and iTBS.

METHODS

Two rTMS and iTBS datasets (n = 163) were used: one randomized controlled trial dataset (RCTD; n = 96) and one outpatient dataset (OPD; n = 67). Frontal theta and non-linear EEG features that reflect trend, stability, and complexity were extracted. Pretreatment frontal EEG and ML algorithms, including classical support vector machine(SVM), random forest(RF), XGBoost, and CatBoost, were analyzed. Responses were defined as ≥50 % depression improvement after treatment. Response rates between those with and without pretreatment prediction in another independent outpatient cohort (n = 208) were compared.

RESULTS

Prediction accuracy using combined EEG features by SVM was better than frontal theta by logistic regression. The accuracy for OPD patients significantly dropped using the RCTD-trained SVM model. Modern ML models, especially RF (rTMS = 83.3 %, iTBS = 88.9 %, p-value(ACC > NIR) < 0.05 for iTBS), performed significantly above chance and had higher accuracy than SVM using both selected features (p < 0.05, FDR corrected for multiple comparisons) or all EEG features. Response rates among those receiving prediction before treatment were significantly higher than those without prediction (p = 0.035).

CONCLUSION

The first study combining linear and non-linear EEG features could accurately predict responses to left PFC iTBS. The bootstraps-based ML model (i.e., RF) had the best predictive accuracy for rTMS and iTBS.

Non-inferiority of intermittent theta burst stimulation over the left V1 vs. classical target for depression: A randomized, double-blind trial

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) targeting the visual cortex (VC) has shown antidepressant effects for major depressive disorder (MDD) in sham-controlled trials, but comparisons with rTMS targeting the left dorsolateral prefrontal cortex (DLPFC) are lacking. We aimed to determine the non-inferiority of intermittent theta-burst stimulation (iTBS) over VC vs DLPFC for MDD.

METHODS

Participants randomly received navigated iTBS over the left V1 or the left DLPFC twice daily for 14 days with a 3-month follow-up. The primary outcome was change in Hamilton Depression Rating Scale (HAMD-17) score from baseline to treatment end, with 2.5 points as the non-inferiority margin. Secondary outcomes included: improvement in Montgomery-Asberg Depression Rating Scale (MADRS), Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA); response and remission rates; suicidal ideation and adverse events.

RESULTS

Of 75 randomized patients, 67 completed full treatment, including 52 first-episode patients and 15 relapsers. The primary outcome indicated the non-inferiority of VC (adjusted difference 1.14, lower 97.5 % CI -1.24; p = .002), confirmed by improvements in objective cognitive task and protein levels, as did most secondary outcomes. Reduced suicidal ideation after treatment, incidence of eye discomfort and pain score were lower in the VC group.

CONCLUSIONS

Left VC iTBS has the potential to be non-inferior to DLPFC iTBS in most first-episode MDD in improving depressive symptoms and cognitive function, with less suicidal ideation and adverse events.

LIMITATIONS

Given the limited sample size, the lack of a sham control and the use of antidepressants, the findings should be interpreted with caution.

Stanford neuromodulation therapy for treatment-resistant depression: a systematic review

Objective

This systematic review of randomized controlled studies (RCTs) and observational studies evaluated the efficacy and safety of stanford neuromodulation therapy (SNT) for patients with treatment-resistant depression (TRD).

Methods

A systematic search (up to 25 September, 2023) of RCTs and single-arm prospective studies was conducted.

Results

One RCT (n = 29) and three single-arm prospective studies (n = 34) met the study entry criteria. In the RCT, compared to sham, active SNT was significantly associated with higher rates of antidepressant response (71.4% versus 13.3%) and remission (57.1% versus 0%). Two out of the three single-arm prospective studies reported the percentage of antidepressant response after completing SNT, ranging from 83.3% (5/6) to 90.5% (19/21). In the three single-arm prospective studies, the antidepressant remission rates ranged from 66.7% (4/6) to 90.5% (19/21). No severe adverse events occurred in all the four studies.

Conclusion

This systematic review found SNT significantly improved depressive symptoms in patients with TRD within 5 days, without severe adverse events.

The Comparison of Early Hemodynamic Response to Single-Pulse Transcranial Magnetic Stimulation following Inhibitory or Excitatory Theta Burst Stimulation on Motor Cortex

We present a new study design aiming to enhance the understanding of the mechanism by which continuous theta burst stimulation (cTBS) or intermittent theta burst stimulation (iTBS) paradigms elicit cortical modulation. Using near-infrared spectroscopy (NIRS), we compared the cortical hemodynamics of the previously inhibited (after cTBS) or excited (after iTBS) left primary motor cortex (M1) as elicited by single-pulse TMS (spTMS) in a cross-over design. Mean relative changes in hemodynamics within 6 s of the stimulus were compared using a two-sample t-test (p < 0.05) and linear mixed model between real and sham stimuli and between stimuli after cTBS and iTBS. Only spTMS after cTBS resulted in a significant increase (p = 0.04) in blood volume (BV) compared to baseline. There were no significant changes in other hemodynamic parameters (oxygenated/deoxygenated hemoglobin). spTMS after cTBS induced a larger increase in BV than spTMS after iTBS (p = 0.021) and sham stimulus after cTBS (p = 0.009). BV showed no significant difference between real and sham stimuli after iTBS (p = 0.37). The greater hemodynamic changes suggest increased vasomotor reactivity after cTBS compared to iTBS. In addition, cTBS could decrease lateral inhibition, allowing activation of surrounding areas after cTBS.

Baseline markers of cortical excitation and inhibition predict response to theta burst stimulation treatment for youth depression

Theta burst stimulation (TBS), a specific form of repetitive transcranial magnetic stimulation (TMS), is a promising treatment for youth with Major Depressive Disorder (MDD) who do not respond to conventional therapies. However, given the variable response to TBS, a greater understanding of how baseline features relate to clinical response is needed to identify which patients are most likely to benefit from this treatment. In the current study, we sought to determine if baseline neurophysiology, specifically cortical excitation and/or inhibition, is associated with antidepressant response to TBS. In two independent open-label clinical trials, youth (aged 16-24 years old) with MDD underwent bilateral dorsolateral prefrontal cortex (DLPFC) TBS treatment. Clinical trial one and two consisted of 10 and 20 daily sessions of bilateral DLPFC TBS, respectively. At baseline, single-pulse TMS combined with electroencephalography was used to assess the neurophysiology of 4 cortical sites: bilateral DLPFC and inferior parietal lobule. Measures of cortical excitation and inhibition were indexed by TMS-evoked potentials (i.e., P30, N45, P60, N100, and P200). Depression severity was measured before, during and after treatment completion using the Hamilton Rating Scale for Depression-17. In both clinical trials, the baseline left DLPFC N45 and P60, which are believed to reflect inhibitory and excitatory mechanisms respectively, were predictors of clinical response. Specifically, greater (i.e., more negative) N45 and smaller P60 baseline values were associated with greater treatment response to TBS. Accordingly, cortical excitation and inhibition circuitry of the left DLPFC may have value as a TBS treatment response biomarker for youth with MDD.Clinical trial 1 registration number: NCT02472470 (June 15, 2015).Clinical trial 2 registration number: NCT03708172 (October 17, 2018).

Effects of intermittent theta-burst transcranial magnetic stimulation on post-traumatic stress disorder symptoms: A randomized controlled trial

Post-traumatic stress disorder (PTSD) is a prevalent and debilitating illness, which can be alleviated by transcranial magnetic stimulation (TMS). Intermittent theta burst stimulation (iTBS), a newer form of repetitive transcranial magnetic stimulation (rTMS), offers the advantage of shorter treatment sessions compared to the standard 10 Hz rTMS treatment. In order to compare the two forms of TMS, we enrolled 75 participants aged between 18 and 55 years who presented with (PCL-C) scale score of at least 50. Participants were randomly assigned to groups in a ratio of 1:1:1, receiving either 10 Hz rTMS, iTBS, or sham-controlled iTBS. Participants in the two treatment groups underwent 15 therapies which consisted of 1800 pulses and targeted the right dorsolateral prefrontal cortex (DLPFC). The main outcomes included changes in scores on the PCL-C and the Post-Traumatic Growth Inventory (PTGI). After intervention, the PCL-C and PTGI scores in iTBS and rTMS groups were significantly different from those in sham-controlled iTBS group. No significant differences in PCL-C and PTGI were found between the two active treatment groups. ITBS, with a shorter treatment duration, can effectively improve the symptoms of PTSD, with no significant difference in effect from that of rTMS. Future studies need to further elucidate the mechanisms, optimize the parameters and investigate the therapeutic potential and efficacy of iTBS in PTSD.

Personalized, parcel-guided rTMS for the treatment of major depressive disorder: Safety and proof of concept

BACKGROUND

Not all patients with major depressive disorder (MDD) benefit from the US Food and Drug Administration-approved use of repetitive transcranial magnetic stimulation (rTMS) at the dorsolateral prefrontal cortex. We may be undertreating depression with this one-size-fits-all rTMS strategy.

METHODS

We present a retrospective review of targeted and connectome-guided rTMS in 26 patients from Cingulum Health from 2020 to 2023 with MDD or MDD with associated symptoms. rTMS was conducted by identifying multiple cortical targets based on anomalies in individual functional connectivity networks as determined by machine learning connectomic software. Quality of life assessed by the EuroQol (EQ-5D) score and depression symptoms assessed by the Beck Depression Inventory (BDI) were administered prior to treatment, directly after, and at a follow-up consultation.

RESULTS

Of the 26 patients treated with rTMS, 16 (62%) attained remission after treatment. Of the 19 patients who completed follow-up assessments after an average interval of 2.6 months, 11 (58%) responded to treatment and 13 (68%) showed significant remission. Between patients classified with or without treatment-resistant depression, there was no difference in BDI improvement. Additionally, there was significant improvement in quality of life after treatment and during follow-up compared to baseline.

LIMITATIONS

This review is retrospective in nature, so there is no control group to assess the placebo effect on patient outcomes.

CONCLUSION

The personalized, connectome-guided approach of rTMS is safe and may be effective for depression. This personalized rTMS treatment allows for co-treatment of multiple disorders, such as the comorbidity of depression and anxiety.

Abnormal individualized peak functional connectivity toward potential repetitive transcranial magnetic stimulation treatment of autism spectrum disorder

Functional connectivity (FC) derived from resting-state functional magnetic resonance imaging has been widely applied to guide precise repetitive transcranial magnetic stimulation (rTMS). The left, right, and bilateral dorsolateral prefrontal cortices (DLPFC) have been used as rTMS treatment target regions for autism spectrum disorder (ASD), albeit with moderate efficacy. Thus, we aimed to develop an individualized localization method for rTMS treatment of ASD. We included 266 male ASDs and 297 male typically-developed controls (TDCs) from the Autism Brain Imaging Data Exchange Dataset. The nucleus accumbens (NAc) was regarded as a promising effective region, which was used as a seed and individualized peak FC strength in the DLPFC was compared between ASD and TDC. Correlation analysis was conducted between individualized peak FC strength and symptoms in ASD. We also investigated the spatial distribution of individualized peak FC locations in the DLPFC and conducted voxel-wise analysis to compare NAc-based FC between the two groups. ASD showed stronger peak FC in the right DLPFC related to TDC (Cohen's d = -.19, 95% CI: -0.36 to -0.03, t = -2.30, p = .02). Moreover, negative correlation was found between the peak FC strength in the right DLPFC and Autism Diagnostic Observation Schedule (ADOS) scores, which assessed both the social communication and interaction (r = -.147, p = .04, uncorrected significant), and stereotyped behaviors and restricted interests (r = -.198, p = .02, corrected significant). Peak FC locations varied substantially across participants. No significant differences in NAc-based FC in the DLPFC were found in the voxel-wise comparison. Our study supports the use of individualized peak FC-guided precise rTMS treatment of male ASD. Moreover, stimulating the right DLPFC might alleviate core symptoms of ASD.

Bilateral theta burst stimulation for patients with acute unipolar or bipolar depressive episodes: A systematic review of randomized controlled studies

OBJECTIVE

This meta-analysis of randomized controlled trials (RCTs) evaluated the overall efficacy and safety of bilateral theta-burst stimulation (TBS) as an intervention for patients with mood disorders.

METHODS

A systematic search (up to December 7, 2022) of RCTs was conducted to address the study aims. A random-effects meta-analysis was performed by including study-defined responses and remission as primary outcomes.

RESULTS

Analyses included six RCTs comprising 285 participants with major depressive disorder (MDD) (n = 233) or a depressive episode in the course of bipolar disorder (BD) (n = 52) who had undergone active bilateral TBS (n = 142) versus sham stimulation (n = 143). Active bilateral TBS outperformed sham stimulation with respect to study-defined improvements (55.1 % versus 20.3 %, 4 RCTs, n = 152, 95%CI: 1.63 to 4.39, P < 0.0001; I2 = 0 %) and remission rates (37.2 % versus 14.3 %, 2 RCTs, n = 85, 95%CI: 1.13 to 5.95, P = 0.02; I2 = 0 %) in MDD patients but not those with bipolar or unipolar mixed depression. Superiority of active bilateral TBS over sham stimulation was confirmed for improvements in depressive symptoms at post-bilateral TBS assessments and 8-week follow-ups in patients with either MDD or mixed depression (all P < 0.05). Discontinuation rates due to any reason and adverse events (i.e., headache, dizziness) were similar between TBS and sham stimulation groups with MDD or mixed depression (all P > 0.05).

CONCLUSION

Bilateral TBS targeting the dorsolateral prefrontal cortex (DLPFC) appears to be a well-tolerated form of repetitive transcranial magnetic stimulation (rTMS) that has substantial antidepressant effects, particularly in patients with MDD. Effects of bilateral TBS on bipolar and unipolar mixed depression should be further investigated.

A naturalistic study comparing the efficacy of unilateral and bilateral sequential theta burst stimulation in treating major depression - the U-B-D study protocol

BACKGROUND

Major depressive disorder (MDD) is a prevalent mental health condition affecting millions worldwide, leading to disability and reduced quality of life. MDD poses a global health priority due to its early onset and association with other disabling conditions. Available treatments for MDD exhibit varying effectiveness, and a substantial portion of individuals remain resistant to treatment. Repetitive transcranial magnetic stimulation (rTMS), applied to the left and/or right dorsolateral prefrontal cortex (DLPFC), is an alternative treatment strategy for those experiencing treatment-resistant MDD. The objective of this study is to investigate whether this newer form of rTMS, namely theta burst stimulation (TBS), when performed unilaterally or bilaterally, is efficacious in treatment-resistant MDD.

METHODS

In this naturalistic, randomized double-blinded non-inferiority trial, participants with a major depressive episode will be randomized to receive either unilateral (i.e., continuous TBS [cTBS] to the right and sham TBS to the left DLPFC) or bilateral sequential TBS (i.e., cTBS to the right and intermittent TBS [iTBS] to the left DLPFC) delivered 5 days a week for 4-6 weeks. Responders will move onto a 6-month flexible maintenance phase where TBS treatment will be delivered at a decreasing frequency depending on degree of symptom mitigation. Several clinical assessments and neuroimaging and neurophysiological biomarkers will be collected to investigate treatment response and potential associated biomarkers. A non-inferiority analysis will investigate whether bilateral sequential TBS is non-inferior to unilateral TBS and regression analyses will investigate biomarkers of treatment response. We expect to recruit a maximal of 256 participants. This trial is approved by the Research Ethics Board of The Royal's Institute of Mental Health Research (REB# 2,019,071) and will follow the Declaration of Helsinki. Findings will be published in peer-reviewed journals.

DISCUSSION

Comprehensive assessment of symptoms and neurophysiological biomarkers will contribute to understanding the differential efficacy of the tested treatment protocols, identifying biomarkers for treatment response, and shedding light into underlying mechanisms of TBS. Our findings will inform future clinical trials and aid in personalizing treatment selection and scheduling for individuals with MDD.

TRIAL REGISTRATION

The trial is registered on https://clinicaltrials.gov/ct2/home (#NCT04142996).

The antidepressant effect of intermittent theta burst stimulation (iTBS): study protocol for a randomized double-blind sham-controlled trial

BACKGROUND

Intermittent theta burst stimulation (iTBS) when applied over the left dorsolateral prefrontal cortex (DLPFC) has been shown to be equally effective and safe to treat depression compared to traditional repetitive transcranial magnetic stimulation (rTMS) paradigms. This protocol describes a funded single-centre, double-blind, randomized placebo-controlled, clinical trial to investigate the antidepressive effects of iTBS and factors associated with an antidepressive response.

METHODS

In this trial, outpatients (N = 96, aged 22-65 years) meeting the diagnostic criteria for at least moderate depression (Montgomery and Aasberg Depression Rating Scale score ≥ 20) will be enrolled prospectively and receive ten, once-a-day sessions of either active iTBS or sham iTBS to the left DLPFC, localized via a neuronavigation system. Participants may have any degree of treatment resistance. Prior to stimulation, participants will undergo a thorough safety screening and a brief diagnostic assessment, genetic analysis of brain-derived neurotropic factor, 5-HTTLPR and 5-HT1A, and cerebral MRI assessments. A selection of neuropsychological tests and questionnaires will be administered prior to stimulation and after ten stimulations. An additional follow-up will be conducted 4 weeks after the last stimulation. The first participant was enrolled on June 4, 2022. Study completion will be in December 2027. The project is approved by the Regional Ethical Committee of Medicine and Health Sciences, Northern Norway, project number 228765. The trial will be conducted according to Good Clinical Practice and published safety guidelines on rTMS treatment.

DISCUSSION

The aims of the present trial are to investigate the antidepressive effect of a 10-session iTBS protocol on moderately depressed outpatients and to explore the factors that can explain the reduction in depressive symptoms after iTBS but also a poorer response to the treatment. In separate, but related work packages, the trial will assess how clinical, cognitive, brain imaging and genetic measures at baseline relate to the variability in the antidepressive effects of iTBS.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05516095. Retrospectively registered on August 25, 2022.

Antidepressant effects of prolonged intermittent theta-burst stimulation monotherapy at the bilateral dorsomedial prefrontal cortex for medication and standard transcranial magnetic stimulation-resistant major depression: a three arm, randomized, double blind, sham-controlled pilot study

The dorsomedial prefrontal cortex (DMPFC) plays a pivotal role in depression and anxiosomatic symptom modulation. However, DMPFC stimulation using a double-cone coil has demonstrated inconsistent results for antidepressant efficacy. No study thus far has investigated the antidepressant and anti-anxiosomatic effects of prolonged intermittent theta-burst stimulation (piTBS) bilaterally over DMPFC. Furthermore, head-to-head comparisons of antidepressant effects between standard iTBS and piTBS warrant investigation. This double-blind, randomized, sham-controlled trial recruited 34 patients with highly treatment-resistant depression (TRD) unresponsive to antidepressants and standard repetitive transcranial magnetic stimulation (rTMS)/piTBS. These patients were randomly assigned to one of three monotherapy groups (standard iTBS, piTBS, or sham), with treatment administered bilaterally over the DMPFC twice per day for 3 weeks. The primary outcome was the overall changes of 17-item Hamilton Depression Rating Scale (HDRS-17) over 3-weeks intervention. The changes in Depression and Somatic Symptoms Scale (DSSS) as the secondary outcome and the anxiosomatic cluster symptoms as rated by HDRS-17 as the post-hoc outcome were measured. Multivariable generalized estimating equation analysis was performed. Although no differences in overall HDRS-17 changes between three groups were found, the antidepressant efficacy based on DSSS was higher in piTBS than in iTBS and sham at week 3 (group effect,p = 0.003, post-hoc: piTBS > iTBS, p = 0.002; piTBS > sham, p = 0.038). In post-hoc analyses, piTBS had more alleviation in anxiosomatic symptoms than iTBS (group effect, p = 0.002; post-hoc, p = 0.001). This first randomized sham-controlled study directly compared piTBS and iTBS targeting the DMPFC using a figure-of-8 coil and found piTBS may fail to demonstrate a significant antidepressant effect on overall depressive symptoms, but piTBS seems superior in alleviating anxiosomatic symptoms, even in depressed patients with high treatment resistance. This Trial registration (Registration number: NCT04037592). URL: https://clinicaltrials.gov/ct2/show/NCT04037592 .

Trajectory of changes in depressive symptoms after acute repetitive transcranial magnetic stimulation: A meta-analysis of follow-up effects

BACKGROUND

The follow-up effect after acute repetitive transcranial magnetic stimulation (rTMS) for major depressive episodes remains unclear. Furthermore, the benefits of maintenance rTMS are poorly understood.

AIM

To investigate the trajectory of changes in depressive symptoms after acute rTMS and effects of maintenance rTMS during this period.

METHOD

This meta-analysis (PROSPERO: CRD42022374077) searched major databases up to October 1, 2022. Treatment outcome was depressive scores collected at least 3 months after the end of an acute rTMS course for depression. We extracted data at different time points after acute rTMS and categorized by whether maintenance rTMS was performed. A single-stage random-effects dose-response meta-analysis was undertaken to model the nonlinear relationships. Effect sizes were calculated as standardized mean differences (SMDs) with 95% confidence intervals (CIs).

RESULTS

24 eligible studies comprising 911 total patients-225 of whom received maintenance rTMS-were included. Maintenance rTMS contributed to relative stability in patients' mood symptoms during the first 5 months (SMD [95% CI]: 3rd month, -0.10 [-0.30 to 0.10]; 5th month, 0.00 [-0.55 to 0.55]), with heterogeneity characterized as low to moderate. Further analysis revealed that maintenance rTMS performed monthly or more frequently provided sustained benefits for up to 6-12 months. Conversely, patients without maintenance rTMS had moderate to high heterogeneity, although the change in mean mood symptom scores during the 12-month follow-up was also minor (6th month, 0.03 [-0.51 to 0.56]; 12th month, 0.10 [-0.59 to 0.79]).

CONCLUSION

Maintenance rTMS might keep patients' mood relatively stable for up to 5 months after acute rTMS. Monthly or more frequent maintenance rTMS offers greater benefits.

The longer, the better ? Longer left-sided prolonged intermittent theta burst stimulation in patients with major depressive disorder: A randomized sham-controlled study

BACKGROUND

Prolonged intermittent theta-burst stimulation (iTBS) is effective for major depressive disorder (MDD). However, whether longer piTBS treatment in a single session could have antidepressant efficacy remains elusive. Therefore, this double-blind, randomized, sham-controlled study aimed to investigate the antidepressant efficacy of 2 daily piTBS sessions for treating MDD patients with a history of poor responses to at least 1 adequate antidepressant trial in the current episode.

METHODS

All patients received 2 uninterrupted sessions per day for 10 weekdays (i.e., 2 weeks; a total of 20 sessions). Seventy-two patients were recruited and 1:1:1 randomly assigned to one of three groups: piTBS (piTBSx2), 10-Hz rTMS (rTMSx2), or sham treatment (shamx2, randomly assigned to piTBS or rTMS). 10-Hz rTMS group was included as an active comparison group to enhance assay sensitivity.

RESULTS

piTBSx2 group had significantly more responders at week 2 than shamx2 group, but it did not yield better antidepressant effects regarding the %depression changes. The changes of antidepressant scores were not different among the three groups at week 1 (-26.2% vs. -23.3% vs. -22.%) or at week 2 (-34.1% vs. -37.1% vs. -30.1%). Longer treatment duration did not result in stronger placebo effects [sham(piTBS)x2: - 31.7% vs. sham(rTMS)x2: - 26.7%].

CONCLUSION

The present sham-controlled study confirmed that piTBS is an effective antidepressant option, but found no evidence to support that longer piTBS treatment duration resulted in more rapid or better antidepressant effects. A high placebo effect was observed, but longer treatment duration of brain stimulation was not linearly associated with stronger placebo effects.

Variability in Motor Threshold during Transcranial Magnetic Stimulation Treatment for Depression: Neurophysiological Implications

The measurement of the motor threshold (MT) is an important element in determining stimulation intensity during Transcranial Magnetic Stimulation treatment (rTMS). The current recommendations propose its realization at least once a week. The variability in this motor threshold is an important factor to consider as it could translate certain neurophysiological specificities. We conducted a retrospective naturalistic study on data from 30 patients treated for treatment-resistant depression in an rTMS-specialized center. For each patient, weekly motor-evoked potential (MEP) was performed and several clinical elements were collected as part of our clinical interviews. Regarding response to treatment (Patient Health Questionnaire-9 (PHQ-9) before and after treatment), there was a mean difference of -8.88 (-21 to 0) in PHQ9 in the Theta Burst group, of -9.00 (-18 to -1) in the High-Frequency (10 Hz) group, and of -4.66 (-10 to +2) in the Low-Frequency (1 Hz) group. The mean improvement in depressive symptoms was 47% (p < 0.001, effect-size: 1.60). The motor threshold changed over the course of the treatment, with a minimum individual range of 1 point and a maximum of 19 points (total subset), and a greater concentration in the remission group (4 to 10) than in the other groups (3 to 10 in the response group, 1 to 8 in the partial response group, 3 to 19 in the stagnation group). We also note that the difference between MT at week 1 and week 6 was statistically significant only in the remission group, with a different evolutionary profile showing an upward trend in MT. Our findings suggest a potential predictive value of MT changes during treatment, particularly an increase in MT in patients who achieve remission and a distinct "break" in MT around the 4th week, which could predict nonresponse.

Efficacy and safety of intermittent theta burst stimulation versus high-frequency repetitive transcranial magnetic stimulation for patients with treatment-resistant depression: a systematic review

Objective

Intermittent theta-burst stimulation (iTBS), which is a form of repetitive transcranial magnetic stimulation (rTMS), can produce 600 pulses to the left dorsolateral prefrontal cortex (DLPFC) in a stimulation time of just over 3 min. The objective of this systematic review was to compare the safety and efficacy of iTBS and high-frequency (≥ 5 Hz) rTMS (HF-rTMS) for patients with treatment-resistant depression (TRD).

Methods

Randomized controlled trials (RCTs) comparing the efficacy and safety of iTBS and HF-rTMS were identified by searching English and Chinese databases. The primary outcomes were study-defined response and remission.

Results

Two RCTs (n = 474) investigating the efficacy and safety of adjunctive iTBS (n = 239) versus HF-rTMS (n = 235) for adult patients with TRD met the inclusion criteria. Among the two included studies (Jadad score = 5), all were classified as high quality. No group differences were found regarding the overall rates of response (iTBS group: 48.0% versus HF-rTMS group: 45.5%) and remission (iTBS group: 30.0% versus HF-rTMS group: 25.2%; all Ps > 0.05). The rates of discontinuation and adverse events such as headache were similar between the two groups (all Ps > 0.05).

Conclusion

The antidepressant effects and safety of iTBS and HF-rTMS appeared to be similar for patients with TRD, although additional RCTs with rigorous methodology are needed.

Effects of dorsolateral prefrontal cortex stimulation on network topological attributes in young individuals with high-level perceived stress: A randomized controlled trial

Individuals with high-level perceived stress are at higher risk of developing a psychiatric disorder. While repetitive transcranial magnetic stimulation (rTMS) is effective for improving emotional symptoms, there is little evidence of its effect on perceived stress. This randomized sham-controlled trial investigated the effect of rTMS on ameliorating high-level stress and explored the associated changes in brain network activity. Fifty participants with high-level perceived stress were randomly assigned to either the active or sham rTMS group and received 12 active/sham rTMS sessions over four weeks (three per week). Perceived stress score (PSS), Chinese affective scale (CAS) normal and now statuses, and functional network topology were measured. Our results showed greater improvements in PSS and CAS_Normal scores, and reduced path length in the default mode network after active rTMS. Functional activations of the angular gyrus, posterior insula, and prefrontal cortex were also modulated in the active group. There were significant associations between posterior insula efficiency and PSS scores, and between angular efficiency and CAS_Now scores in the active group. These cumulative findings suggest rTMS as a promising intervention for recovery from high-level perceived stress.

A review of critical brain oscillations in depression and the efficacy of transcranial magnetic stimulation treatment

Repetitive transcranial magnetic stimulation (rTMS) and intermittent theta burst stimulation (iTBS) have been proven effective non-invasive treatments for patients with drug-resistant major depressive disorder (MDD). However, some depressed patients do not respond to these treatments. Therefore, the investigation of reliable and valid brain oscillations as potential indices for facilitating the precision of diagnosis and treatment protocols has become a critical issue. The current review focuses on brain oscillations that, mostly based on EEG power analysis and connectivity, distinguish between MDD and controls, responders and non-responders, and potential depression severity indices, prognostic indicators, and potential biomarkers for rTMS or iTBS treatment. The possible roles of each biomarker and the potential reasons for heterogeneous results are discussed, and the directions of future studies are proposed.

Overview of treatment-resistant depression

Patients with major depressive disorder (MDD) often exhibit an inadequate treatment response or failure to achieve remission following treatment with antidepressant drugs. Treatment-resistant depression (TRD) is proposed to identify this clinical scenario. Compared to those without TRD, patients with TRD have significantly lower health-related quality of life in mental and physical dimensions, more functional impairment and productivity loss, and higher healthcare costs. TRD imposes a massive burden on the individual, family, and society. However, a lack of consensus on the TRD definition limits the comparison and interpretation of TRD treatment efficacy across trials. Furthermore, because of the various TRD definitions, there is scarce treatment guideline specifically for TRD, in contrast to the rich treatment guidelines for MDD. In this chapter, common issues related to TRD, such as proper definitions of an adequate antidepressant trial and TRD, were carefully reviewed. Prevalence of and clinical outcomes related to TRD were summarized. We also summarized the staging models ever proposed for the diagnosis of TRD. Furthermore, we highlighted variations in the definition regarding the lack of or an inadequate response in treatment guidelines for depression. Up-to-date treatment options for TRD, including pharmacological strategies, psychotherapeutic interventions, neurostimulation techniques, glutamatergic compounds, and even experimental agents were reviewed.

Outcome of transcranial magnetic intermittent theta-burst stimulation in the treatment of depression - A Swedish register-based study

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) is an established treatment of depression. The more recently introduced intermittent Theta-burst stimulation (iTBS) has shown significant superiority over sham-stimulation and equal effect sizes to a 10 Hz protocol in one clinical trial. The aim of the current study was to investigate the effectiveness and tolerability of iTBS in a naturalistic, clinical setting. Further, we explored demographical and clinical predictors of response.

METHODS

Data was collected from seventeen rTMS-sites in Sweden between January 2018 and May 2021, through the Swedish National Quality register for repetitive Transcranial Magnetic Stimulation (Q-rTMS). We included 542 iTBS-treated patients with unipolar or bipolar depression. Outcome was assessed with Clinical Global Impression Severity and Improvement scores in an intention to treat analysis.

RESULTS

The response rate was 42.1 % and 16.1 % reached remission. The response rate was significantly larger in the oldest age group compared to the youngest (odds ratio 3.46, 95 % confidence interval 1.65-7.22). Less severe level of depression (Montgomery-Åsberg depression rating scale self-assessment < 36) at baseline predicted response and remission. Only <1 % were much or very much worse after treatment. Drop-out rate was 10.9 %. No serious adverse events were reported.

LIMITATIONS

Retrospective analysis of register data. No comparison group.

CONCLUSIONS

In a clinical setting, iTBS was shown to be safe and tolerable and the response rate was similar to that reported from clinical trials. Older age-group and less severe illness predicted response.

Accelerated Repetitive Transcranial Magnetic Stimulation to Treat Major Depression: The Past, Present, and Future

Repetitive transcranial magnetic stimulation (rTMS) is an effective and evidence-based therapy for treatment-resistant major depressive disorder. A conventional course of rTMS applies 20-30 daily sessions over 4-6 weeks. The schedule of rTMS delivery can be accelerated by applying multiple stimulation sessions per day, which reduces the duration of a treatment course with a predefined number of sessions. Accelerated rTMS reduces time demands, improves clinical efficiency, and potentially induces faster onset of antidepressant effects. However, considerable heterogeneity exists across study designs. Stimulation protocols vary in parameters such as the stimulation target, frequency, intensity, number of pulses applied per session or over a course of treatment, and duration of intersession intervals. In this article, clinician-researchers and neuroscientists who have extensive research experience in accelerated rTMS synthesize a consensus based on two decades of investigation and development, from early studies ("Past") to contemporaneous theta burst stimulation, a time-efficient form of rTMS gaining acceptance in clinical settings ("Present"). We propose descriptive nomenclature for accelerated rTMS, recommend avenues to optimize therapeutic and efficiency potential, and suggest using neuroimaging and electrophysiological biomarkers to individualize treatment protocols ("Future"). Overall, empirical studies show that accelerated rTMS protocols are well tolerated and not associated with serious adverse effects. Importantly, the antidepressant efficacy of accelerated rTMS appears comparable to conventional, once daily rTMS protocols. Whether accelerated rTMS induces antidepressant effects more quickly remains uncertain. On present evidence, treatment protocols incorporating high pulse dose and multiple treatments per day show promise and improved efficacy.

Invasive Computational Psychiatry

Computational psychiatry, a relatively new yet prolific field that aims to understand psychiatric disorders with formal theories about the brain, has seen tremendous growth in the past decade. Despite initial excitement, actual progress made by computational psychiatry seems stagnant. Meanwhile, understanding of the human brain has benefited tremendously from recent progress in intracranial neuroscience. Specifically, invasive techniques such as stereotactic electroencephalography, electrocorticography, and deep brain stimulation have provided a unique opportunity to precisely measure and causally modulate neurophysiological activity in the living human brain. In this review, we summarize progress and drawbacks in both computational psychiatry and invasive electrophysiology and propose that their combination presents a highly promising new direction-invasive computational psychiatry. The value of this approach is at least twofold. First, it advances our mechanistic understanding of the neural computations of mental states by providing a spatiotemporally precise depiction of neural activity that is traditionally unattainable using noninvasive techniques with human subjects. Second, it offers a direct and immediate way to modulate brain states through stimulation of algorithmically defined neural regions and circuits (i.e., algorithmic targeting), thus providing both causal and therapeutic insights. We then present depression as a use case where the combination of computational and invasive approaches has already shown initial success. We conclude by outlining future directions as a road map for this exciting new field as well as presenting cautions about issues such as ethical concerns and generalizability of findings.

Different synaptic mechanisms of intermittent and continuous theta-burst stimulations in a severe foot-shock induced and treatment-resistant depression in a rat model

Treatment-resistant depression (TRD) is a condition wherein patients with depression fail to respond to antidepressant trials. A new form of repetitive transcranial magnetic stimulation (rTMS), called theta-burst stimulation (TBS), which includes intermittent theta-burst stimulation (iTBS) and continuous theta-burst stimulation (cTBS), is non-inferior to rTMS in TRD treatment. However, the mechanism of iTBS and cTBS underlying the treatment of TRD in the prefrontal cortex (PFC) remains unclear. Hence, we applied foot-shock stress as a traumatic event to develop a TRD rat model and investigated the different mechanisms of iTBS and cTBS. The iTBS and cTBS treatment were effective in depressive-like behavior and active coping behavior. The iTBS treatments improved impaired long-term potentiation and long-term depression (LTD), whereas the cTBS treatment only improved aberrant LTD. Moreover, the decrease in mature brain-derived neurotrophic factor (BDNF)-related protein levels were reversed by iTBS treatment. The decrease in proBDNF-related protein expression was improved by iTBS and cTBS treatment. Both iTBS and cTBS improved the decreased α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors and downregulation of mammalian target of the rapamycin (mTOR) signaling pathway. The iTBS produces both excitatory and inhibitory synaptic effects, and the cTBS only produces inhibitory synaptic effects in the PFC.

Theta-burst stimulation of TMS treatment for anxiety and depression: A FNIRS study

BACKGROUND

This study aimed to evaluate the intervention effect of intermittent Theta burst stimulation (iTBS) on anxiety and depression by using Functional Near-Infrared Spectroscopy technology for confirming the effect of iTBS on anxiety and depression and providing new parameter basis for the treatment and development of rTMS.

METHOD

37 patients with anxiety and depression were treated with rTMS intervention in iTBS mode, and the symptoms of depression and anxiety were assessed by Hospital Anxiety and Depression Scale at baseline and after 10 times of treatments. The brain activation was assessed by verbal fluency task. The scores of anxiety and depression were analyzed by paired sample t-test.

RESULTS

After 10 times of rTMS treatment in iTBS mode, the symptoms of anxiety and depression in patients were relieved. The anxiety scores before and after treatment were significantly different, and the post-test scores were significantly lower than the pre-test scores. Significant differences in depression scores were observed before and after treatment, and the post-test score was significantly lower than the pre-test score. In the brain functional connection, the connection of various brain regions was strengthened, and the strength of functional connection between all ROIs before the intervention was significantly lower than that after the intervention. Statistical significance was observed.

CONCLUSION

The intervention of iTBS model has a positive effect on improving symptoms and strengthening brain functional connection of patients with anxiety and depression. This performance supports the effectiveness of iTBS model in treating anxiety and depression.

Effect of intermittent theta burst stimulation on suicidal ideation and depressive symptoms in adolescent depression with suicide attempt: A randomized sham-controlled study

BACKGROUND

Suicidal ideation is a serious symptom of major depressive disorder (MDD). Intermittent theta burst stimulation (iTBS) is a safe, effective brain stimulation treatment for alleviating suicidal ideation in adults with MDD. This study aimed to examine the clinical efficacy of iTBS on reducing suicidal ideation in adolescent MDD with suicide attempt.

METHODS

In a randomized, sham-controlled protocol, a total of 10 sessions of iTBS was administrated to the left dorsolateral prefrontal cortex (DLPFC) in patients once a day for two weeks. The suicidal ideation and depressive symptoms were assessed using Beck Scale for Suicide Ideation-Chinese Version (BSI-CV), Hamilton Rating Scale for Depression (HAMD-24), and Self-rating Depression Scale (SDS) at baseline and after 10 treatment sessions.

RESULTS

Forty-five patients were randomized assigned to either active iTBS (n = 23) or sham group (n = 22). The suicidal ideation and depressive symptoms of the active iTBS group were significantly ameliorated over 2 weeks of treatment. Further, higher baseline SDS, HAMD-24 and BSI-CV scores in the active iTBS group were associated with greater reductions.

LIMITATIONS

A larger sample size and double-blinded clinical trial should be conducted to verify the reliability and reproducibility.

CONCLUSIONS

The current study suggested that daily iTBS of the left DLPFC for 2 weeks could effectively and safely alleviate suicidal ideation and mitigate depression in adolescent MDD, especially for individuals with relatively more severe symptoms. Although caution is warranted, the findings could provide further evidence for the effectiveness and safety of iTBS in clinical practice.

Macroscopic resting state model predicts theta burst stimulation response: A randomized trial

Repetitive transcranial magnetic stimulation (rTMS) is a promising alternative therapy for treatment-resistant depression, although its limited remission rate indicates room for improvement. As depression is a phenomenological construction, the biological heterogeneity within this syndrome needs to be considered to improve the existing therapies. Whole-brain modeling provides an integrative multi-modal framework for capturing disease heterogeneity in a holistic manner. Computational modelling combined with probabilistic nonparametric fitting was applied to the resting-state fMRI data from 42 patients (21 women), to parametrize baseline brain dynamics in depression. All patients were randomly assigned to two treatment groups, namely active (i.e., rTMS, n = 22) or sham (n = 20). The active treatment group received rTMS treatment with an accelerated intermittent theta burst protocol over the dorsomedial prefrontal cortex. The sham treatment group underwent the identical procedure but with the magnetically shielded side of the coil. We stratified the depression sample into distinct covert subtypes based on their baseline attractor dynamics captured by different model parameters. Notably, the two detected depression subtypes exhibited different phenotypic behaviors at baseline. Our stratification could predict the diverse response to the active treatment that could not be explained by the sham treatment. Critically, we further found that one group exhibited more distinct improvement in certain affective and negative symptoms. The subgroup of patients with higher responsiveness to treatment exhibited blunted frequency dynamics for intrinsic activity at baseline, as indexed by lower global metastability and synchrony. Our findings suggested that whole-brain modeling of intrinsic dynamics may constitute a determinant for stratifying patients into treatment groups and bringing us closer towards precision medicine.

Effects of bilateral sequential theta-burst stimulation on functional connectivity in treatment-resistant depression: First results

BACKGROUND

Previous studies suggest that transcranial magnetic stimulation exerts antidepressant effects by altering functional connectivity (FC). However, knowledge about this mechanism is still limited. Here, we aimed to investigate the effect of bilateral sequential theta-burst stimulation (TBS) on FC in treatment-resistant depression (TRD) in a sham-controlled longitudinal study.

METHODS

TRD patients (n = 20) underwent a three-week treatment of intermittent TBS of the left and continuous TBS of the right dorsolateral prefrontal cortex (DLPFC). Upon this trial's premature termination, 15 patients had received active TBS and five patients sham stimulation. Resting-state functional magnetic resonance imaging was performed at baseline and after treatment. FC (left and right DLPFC) was estimated for each participant, followed by group statistics (t-tests). Furthermore, depression scores were analyzed (linear mixed models analysis) and tested for correlation with FC.

RESULTS

Both groups exhibited reductions of depression scores, however, there was no significant main effect of group, or group and time. Anticorrelations between DLPFC and the subgenual cingulate cortex (sgACC) were observed for baseline FC, corresponding to changes in depression severity. Treatment did not significantly change DLPFC-sgACC connectivity, but significantly reduced FC between the left stimulation target and bilateral anterior insula.

CONCLUSIONS

Our data is compatible with previous reports on the relevance of anticorrelation between DLPFC and sgACC for treatment success. Furthermore, FC changes between left DLPFC and bilateral anterior insula highlight the effect of TBS on the salience network.

LIMITATIONS

Due to the limited sample size, results should be interpreted with caution and are of exploratory nature.

Pre-frontal stimulation does not reliably increase reward responsiveness

Depression is the leading cause of disability worldwide and its effects can be fatal, with over 800,000 people dying by suicide each year. Neuromodulatory treatments such as transcranial magnetic stimulation (TMS) are being used to treat depression. Despite its endorsement by two regulatory bodies: NICE (2016) and the FDA (2008), there are major questions about the treatment efficacy and biological mechanisms of TMS. Ahn et al.'s (2013) justified the use of TMS in a clinical context in an important study indicating that excitatory TMS increases reward responsiveness. A pseudo-replication of this study by Duprat et al., (2016) also found a similar effect of active TMS, but only with the addition of an exploratory covariate to the analyses-trait reward responsiveness. Here we replicate Ahn et al.'s (2013) key study, and to test the reliability of the effects, and their dependency on trait reward responsiveness as described by Duprat et al., (2016). Using excitatory and sham TMS, we tested volunteers using the probabilistic learning task to measure their reward responsiveness both before and after stimulation. We also examined affect (positive, negative) following stimulation. Irrespective of TMS, the task was shown to be sensitive to reward responsiveness. However, we did not show TMS to be effective in increasing reward responsiveness and we did not replicate Ahn et al., (2013) or Duprat et al., (2016)'s key findings for TMS efficacy, where we provide evidence favouring the null. Moreover, exploratory analyses suggested following active stimulation, positive affect was reduced. Given our findings, we question the basic effects, which support the use of TMS for depression, particularly considering potential deleterious effects of reduced positive affect in patients with depression.

Prognostic factors in major depressive disorder: comparing responders and non-responders to Repetitive Transcranial Magnetic Stimulation (rTMS), a naturalistic retrospective chart review

AIM

Repetitive transcranial magnetic stimulation (rTMS) is widely utilized as an effective treatment for major depressive disorder (MDD) with varying response rates. Factors associated with better treatment outcome remain scarce. This naturalistic retrospective chart review hopes to shed light on easily obtainable and measurable predictive factors for patients referred to rTMS.

METHODS

Protocol parameters, medication, rated scales, rTMS protocols, and treatment outcomes were reviewed for 196 patients with MDD who received rTMS at Saint Boniface Hospital between 2013 and 2019. Logistic regression and marginal effects were used to assess the different predictor variables for response (50% reduction or more on the Hamilton Depression Rating Scale (Ham-D)) and remission (Ham-D of ≤7 by the last session).

RESULTS

HamD at 10 sessions was predictive of remission, and Sheehan Disability Scale (SDS) at 10 sessions was predictive of response to rTMS. Ham-D, SDS, and Beck Anxiety Inventory were predictive of remission and response by Beck Anxiety Inventory 20 sessions. High frequency rTMS had a similar response and remission rate to low frequency, but higher response rate to intermittent Theta Burst Stimulation with no difference in remission rate. Positive predictive factors of response were lower age and bupropion use. Negative predictive factors were antipsychotics, anticonvulsants, or benzodiazepine use. For remission, antipsychotics or anticonvulsants use were negative predictors; bupropion use and higher resting motor threshold were positive predictors. Severity of depression as measured by baseline HamD was not associated with different probabilities of treatment success.

Add-On Intermittent Theta Burst Stimulation Improves the Efficacy of First-Episode and Recurrent Major Depressive Disorder: Real-World Clinical Practice

OBJECTIVE

Repetitive transcranial magnetic stimulation (rTMS) is an effective and evidence-based treatment for major depressive disorder (MDD). This retrospective study aimed to explore the efficacy of add-on iTBS treatment in MDD in real-world clinical practice.

METHODS

One hundred and fifty-nine inpatients with MDD in a general hospital were included in this study. These patients were treated with at least 8 sessions of iTBS, in addition to antidepressants and supportive psychotherapy. Symptoms of depression and anxiety were assessed with the Hamilton Depression Rating Scale (HDRS) and the Hamilton Rating Scale for Anxiety (HAMA) at baseline and after 2-4 weeks of treatment. The improvement degree of depressive and anxious symptoms was compared between the first-episode MDD (n=107) and recurrent MDD (n=52) groups.

RESULTS

Depressive and anxious symptoms were reduced significantly after the add-on iTBS treatment; the response and remission rates in the first-episode MDD group were 55.14% and 28.97%, which were 63.46% and 28.85% for the recurrent MDD group, respectively (P>0.05). The response rate and remission rate of anxiety in the first-episode MDD group was 64.13% and 57.45% for HAMA, and 66.67% and 62.50% for the recurrent MDD group (P>0.05).

CONCLUSION

Our findings indicated that antidepressant and anti-anxiety efficacy of add-on iTBS treatment remains equivocal in real-world clinical practice, regardless of a first-episode depression diagnosis or recurrent depression.