Efficacy of repetitive transcranial magnetic stimulation in treatment-resistant depression: the evidence thus far

Phosphatidic acid is involved in regulation of autophagy in neurons in vitro and in vivo

Major depressive disorder (MDD) is a common and severe psychiatric disease, which does not only lead to variety of neuropsychiatric symptoms, but unfortunately in a relatively large proportion of cases also to suicide. The pathogenesis of MDD still requires definition. We have previously shown that ceramide is increased in the blood plasma of patients with MDD. In mouse models of MDD, which are induced by treatment with corticosterone or application of chronic unpredictable stress, increased blood plasma ceramide also increased and caused an inhibition of phospholipase D in endothelial cells of the hippocampus and reduced phosphatidic acid levels in the hippocampus. Here, we demonstrated that corticosterone treatment of PC12 cells resulted in reduced cellular autophagy, which is corrected by treatment with phosphatidic acid. In vivo, treatment of mice with corticosterone or chronic unpredictable stress also reduced autophagy in hippocampus neurons. Autophagy was normalized upon i.v. injection of phosphatidic acid in these mouse models of MDD. In an attempt to identify targets of phosphatidic acid in neurons, we demonstrated that corticosterone reduced levels of the ganglioside GM1 in PC-12 cells and the hippocampus of mice, which were normalized by treatment of cells or i.v. injection of mice with phosphatidic acid. GM1 application also normalized autophagy in cultured neurons. Phosphatidic acid and GM1 corrected stress-induced alterations in behavior, i.e., mainly anxiety and anhedonia, in experimental MDD in mice. Our data suggest that phosphatidic acid may regulate via GM1 autophagy in neurons.

Water and brain function: effects of hydration status on neurostimulation with transcranial magnetic stimulation

Neurostimulation/neurorecording are tools to study, diagnose, and treat neurological/psychiatric conditions. Both techniques depend on volume conduction between scalp and excitable brain tissue. Here, we examine how neurostimulation with transcranial magnetic stimulation (TMS) is affected by hydration status, a physiological variable that can influence the volume of fluid spaces/cells, excitability, and cellular/global brain functioning. Normal healthy adult participants (32, 9 males) had common motor TMS measures taken in a repeated-measures design from dehydrated (12-h overnight fast/thirst) and rehydrated (identical dehydration protocol followed by rehydration with 1 L water in 1 h) testing days. The target region was left primary motor cortex hand area. Response at the target muscle was recorded with electromyography. Urinalysis confirmed hydration status. Motor hotspot shifted in half of participants. Motor threshold decreased in rehydration, indicating increased excitability. Even after redosing/relocalizing TMS to the new threshold/hotspot, rehydration still showed evidence of increased excitability: recruitment curve measures generally shifted upward and the glutamate-dependent paired-pulse protocol, short intracortical facilitation (SICF), was increased. Short intracortical inhibition (SICI), long intracortical inhibition (LICI), long intracortical facilitation (LICF), and cortical silent period (CSP) were relatively unaffected. The hydration perturbations were mild/subclinical based on the magnitude/speed and urinalysis. Motor TMS measures showed evidence of expected physiological changes of osmotic challenges. Rehydration showed signs of macroscopic and microscopic volume changes including decreased scalp-cortex distance (brain closer to stimulator) and astrocyte swelling-induced glutamate release. Hydration may be a source of variability affecting any techniques dependent on brain volumes/volume conduction. These concepts are important for researchers/clinicians using such techniques or dealing with the wide variety of disease processes involving water balance.NEW & NOTEWORTHY Hydration status can affect brain volumes and excitability, which should affect techniques dependent on electrical volume conduction, including neurostimulation/recording. We test the previously unknown effects of hydration on neurostimulation with TMS and briefly review relevant physiology of hydration. Rehydration showed lower motor threshold, shifted motor hotspot, and generally larger responses even after compensating for threshold/hotspot changes. This is important for clinical and research applications of neurostimulation/neurorecording and the many clinical disorders related to water balance.

Association between rTMS-induced changes in inflammatory markers and improvement in psychiatric diseases: a systematic review

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) has recently gained relevance in treating different psychiatric disorders. Limited evidence suggests that the beneficial effects of rTMS on psychopathology could be at least partly mediated through changes in inflammatory response. This systematic review summarizes the literature on whether rTMS can modulate inflammatory markers and thus positively influence the course of psychiatric illnesses.

MATERIALS AND METHODS

A systematic review of rTMS and inflammatory markers in psychiatric diseases was conducted according to PRISMA guidelines. Information on the association between rTMS treatment response and changes of inflammatory markers was extracted. The quality of the studies was assessed using the National Heart, Lung, and Blood Institute for human studies and the Systematic Review Center for Laboratory Animal Experimentation for animal studies.

RESULTS

This review includes 17 studies (2 animal and 15 human studies) on the relationship between rTMS treatment response and changes of inflammatory markers. Positive changes in microglial activity and anti-inflammatory effects were associated with behavioral improvement in animal models of depression. However, these findings have not been consistently replicated in human studies focusing on treatment-resistant depression. While several studies reported rTMS-induced alterations in peripheral inflammatory markers, only two could demonstrate their association to clinical treatment response. Notably, most studies showed poor or moderate quality in the bias assessment.

CONCLUSIONS

While certain human studies suggest an association between rTMS-induced anti-inflammatory effects and improvement in psychopathology, heterogeneity, and underpowered analyses constrain the generalizability of these results. The discrepancy between animal and human findings highlights the need for larger, standardized human studies.

TRIAL REGISTRATION

(PROSPERO Registration: CRD42023492732).

Physiotherapy for patients with depression: Recent research progress

Depression, a common mental illness, seriously affects the health of individuals and has deleterious effects on society. The prevention and treatment of depression has drawn the attention of many researchers and has become an important social issue. The treatment strategies for depression include drugs, psychotherapy, and physiotherapy. Drug therapy is ineffective in some patients and psychotherapy has treatment limitations. As a reliable adjuvant therapy, physiotherapy compensates for the shortcomings of drug and psychotherapy and effectively reduces the disease recurrence rate. Physiotherapy is more scientific and rigorous, its methods are diverse, and to a certain extent, provides more choices for the treatment of depression. Physiotherapy can relieve symptoms in many ways, such as by improving the levels of neurobiochemical molecules, inhibiting the inflammatory response, regulating the neuroendocrine system, and increasing neuroplasticity. Physiotherapy has biological effects similar to those of antidepressants and may produce a superimposed impact when combined with other treatments. This article summarizes the findings on the use of physiotherapy to treat patients with depression over the past five years. It also discusses several methods of physiotherapy for treating depression from the aspects of clinical effect, mechanism of action, and disadvantages, thereby serving as a reference for the in-depth development of physiotherapy research.

Optogenetic behavioral studies in depression research: A systematic review

Optogenetics has made substantial contributions to our understanding of the mechanistic underpinnings of depression. This systematic review employs quantitative analysis to investigate the impact of optogenetic stimulation in mice and rats on behavioral alterations in social interaction, sucrose consumption, and mobility. The review analyses optogenetic behavioral studies using standardized behavioral tests to detect behavioral changes induced via optogenetic stimulation in stressed or stress-naive mice and rats. Behavioral changes were evaluated as either positive, negative, or not effective. The analysis comprises the outcomes of 248 behavioral tests of 168 studies described in 37 articles, including negative and null results. Test outcomes were compared for each behavior, depending on the animal cohort, applied type of stimulation and the stimulated neuronal circuit and cell type. The presented synthesis contributes toward a comprehensive picture of optogenetic behavioral research in the context of depression.

The Economics of Treatment for Depression

The global prevalence of depression has risen over the past three decades across all socioeconomic groups and geographic regions, with a particularly rapid increase in prevalence among adolescents (aged 12-17 years) in the United States. Depression imposes large health, economic, and societal costs, including reduced life span and quality of life, medical costs, and reduced educational attainment and workplace productivity. A wide range of treatment modalities for depression are available, but socioeconomic disparities in treatment access are driven by treatment costs, lack of culturally tailored options, stigma, and provider shortages, among other barriers. This review highlights the need for comparative research to better understand treatments' relative efficacy, cost-effectiveness, scalability, and potential heterogeneity in efficacy across socioeconomic groups and country and cultural contexts. To address the growing burden of depression, mental health policy could consider reducing restrictions on the supply of providers, implementing digital interventions, reducing stigma, and promoting healthy lifestyles.

French Society for Biological Psychiatry and Neuropsychopharmacology (AFPBN) guidelines for the management of patients with partially responsive depression and treatment-resistant depression: Update 2024

INTRODUCTION

The purpose of this update is to add newly approved nomenclatures and treatments as well as treatments yet to be approved in major depressive disorder, thus expanding the discussions on the integration of resistance factors into the clinical approach.

METHODS

Unlike the first consensus guidelines based on the RAND/UCLA Appropriateness Method, the French Association for Biological Psychiatry and Neuropsychopharmacology (AFPBN) developed an update of these guidelines for the management of partially responsive depression (PRD) and treatment-resistant depression (TRD). The expert guidelines combine scientific evidence and expert clinicians' opinions to produce recommendations for PRD and TRD.

RESULTS

The recommendations addressed three areas judged as essential for updating the previous 2019 AFPBN guidelines for the management of patients with TRD: (1) the identification of risk factors associated with TRD, (2) the therapeutic management of patients with PRD and TRD, and (3) the indications, the modalities of use and the monitoring of recent glutamate receptor modulating agents (esketamine and ketamine).

CONCLUSION

These consensus-based guidelines make it possible to build bridges between the available empirical literature and clinical practice, with a highlight on the 'real world' of the clinical practice, supported by a pragmatic approach centred on the experience of specialised prescribers in TRD.

Neuroplasticity of the left dorsolateral prefrontal cortex in patients with treatment-resistant depression as indexed with paired associative stimulation: a TMS-EEG study

Major depressive disorder affects over 300 million people globally, with approximately 30% experiencing treatment-resistant depression (TRD). Given that impaired neuroplasticity underlies depression, the present study focused on neuroplasticity in the dorsolateral prefrontal cortex (DLPFC). Here, we aimed to investigate the differences in neuroplasticity between 60 individuals with TRD and 30 age- and sex-matched healthy controls (HCs). To induce neuroplasticity, participants underwent a paired associative stimulation (PAS) paradigm involving peripheral median nerve stimulation and transcranial magnetic stimulation (TMS) targeting the left DLPFC. Neuroplasticity was assessed by using measurements combining TMS with EEG before and after PAS. Both groups exhibited significant increases in the early component of TMS-evoked potentials (TEP) after PAS (P < 0.05, paired t-tests with the bootstrapping method). However, the HC group demonstrated a greater increase in TEPs than the TRD group (P = 0.045, paired t-tests). Additionally, event-related spectral perturbation analysis highlighted that the gamma power significantly increased after PAS in the HC group, whereas it was decreased in the TRD group (P < 0.05, paired t-tests with the bootstrapping method). This gamma power modulation revealed a significant group difference (P = 0.006, paired t-tests), indicating an inverse relationship for gamma power modulation. Our findings underscore the impaired neuroplasticity of the DLPFC in individuals with TRD.

Manifold alteration between major depressive disorder and healthy control subjects using dynamic mode decomposition in resting-state fMRI data

Background

The World Health Organization has reported that approximately 300 million individuals suffer from the mood disorder known as MDD. Non-invasive measurement techniques have been utilized to reveal the mechanism of MDD, with rsfMRI being the predominant method. The previous functional connectivity and energy landscape studies have shown the difference in the coactivation patterns between MDD and HCs. However, these studies did not consider oscillatory temporal dynamics.

Methods

In this study, the dynamic mode decomposition, a method to compute a set of coherent spatial patterns associated with the oscillation frequency and temporal decay rate, was employed to investigate the alteration of the occurrence of dynamic modes between MDD and HCs. Specifically, The BOLD signals of each subject were transformed into dynamic modes representing coherent spatial patterns and discrete-time eigenvalues to capture temporal variations using dynamic mode decomposition. All the dynamic modes were disentangled into a two-dimensional manifold using t-SNE. Density estimation and density ratio estimation were applied to the two-dimensional manifolds after the two-dimensional manifold was split based on HCs and MDD.

Results

The dynamic modes that uniquely emerged in the MDD were not observed. Instead, we have found some dynamic modes that have shown increased or reduced occurrence in MDD compared with HCs. The reduced dynamic modes were associated with the visual and saliency networks while the increased dynamic modes were associated with the default mode and sensory-motor networks.

Conclusion

To the best of our knowledge, this study showed initial evidence of the alteration of occurrence of the dynamic modes between MDD and HCs. To deepen understanding of how the alteration of the dynamic modes emerges from the structure, it is vital to investigate the relationship between the dynamic modes, cortical thickness, and surface areas.

Personalized Neuromodulation: A Novel Strategy for Improving Tinnitus Treatment

This study evaluated the efficacy of personalized neuromodulation, where treatment modalities are chosen based on the patient's responses in a pilot trial. A total of 71 patients with tinnitus were divided into two groups: a personalized group and a randomized neuromodulation group. In the personalized group (n = 35), repetitive transcranial magnetic stimulation (rTMS) and transcranial direct-current stimulation (tDCS) were assessed in a pilot trial, and responsive modalities were administered to 16 patients, while the non-responders (n = 19) were randomly assigned to rTMS, tDCS, or combined modalities. Patients in the randomized group (n = 36) were randomly allocated to rTMS, tDCS, or combined modalities. The Tinnitus Handicap Inventory (THI) score improvement after 10 sessions of each neuromodulation was significantly greater in the personalized group than in the randomized group (p = 0.043), with no significant differences in tinnitus loudness, distress, or awareness. The treatment success rate was highest in the personalized responder subgroup (92.3%), and significantly greater than that in the non-responder subgroup (53.0%; p = 0.042) and the randomized group (56.7%; p = 0.033). Personalized neuromodulation, where the treatment modality is chosen based on the patient's responses in a pilot trial, is an advantageous strategy for treating tinnitus.

Psychiatric sequelae of traumatic brain injury - future directions in research

Despite growing appreciation that traumatic brain injury (TBI) is an important public health burden, our understanding of the psychiatric and behavioural consequences of TBI remains limited. These changes are particularly detrimental to a person's sense of self, their relationships and their participation in the wider community, and they continue to have devastating individual and cumulative effects long after TBI. This Review relates specifically to TBIs that confer objective clinical or biomarker evidence of structural brain injury; symptomatic head injuries without such evidence are outside the scope of this article. Common psychiatric, affective and behavioural sequelae of TBI and their proposed underlying mechanisms are outlined, along with a brief overview of current treatments. Suggestions for how scientists and clinicians can work together in the future to address the chasms in clinical care and knowledge are discussed in depth.

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 of repetitive transcranial magnetic stimulation (rTMS) adjunctive therapy for major depressive disorder (MDD) after two antidepressant treatment failures: meta-analysis of randomized sham-controlled trials

BACKGROUND

Several meta-analyses demonstrated the efficacy of unilateral High-Frequency Left-sided (HFL) repetitive Transcranial Magnetic Stimulation (rTMS) for individuals with Major Depressive Disorder (MDD); however, results are contradictory due to heterogeneity of the included studies.

METHODS

A systematic literature review (SLR) of English language articles published since 2000 was performed in March 2022 on PubMed and Scopus databases. Empirical evidence on the relative efficacy of rTMS treatment compared with standard pharmacotherapy in Treatment-Resistant Depression (TRD) were extracted. Random effects models were used to assess the effects of rTMS on response and remission rates.

RESULTS

19 randomized double-blinded sham-controlled studies were included for quantitative analysis for response (n = 854 patients) and 9 studies for remission (n = 551 patients). The risk ratio (RR) for response and remission are 2.25 and 2.78, respectively for patients after two treatment failures using rTMS as add-on treatment compared to standard pharmacotherapy. Cochrane's Q test showed no significant heterogeneity. No publication bias was detected.

CONCLUSIONS

rTMS is significantly more effective than sham rTMS in TRD in response and remission outcomes and may be beneficial as an adjunctive treatment in patients with MDD after two treatment failures. This finding is consistent with previous meta-analyses; however, the effect size was smaller than in the formerly published literature.

Delay Analysis in Closed-Loop EEG Phase-Triggered Transcranial Magnetic Stimulation

The recent development of closed-loop EEG phase-triggered transcranial magnetic stimulation (TMS) has advanced potential applications of adaptive neuromodulation based on the current brain state. Closed-loop TMS involves instantaneous acquisition of the EEG rhythm, timing prediction of the target phase, and triggering of TMS. However, the accuracy of EEG phase prediction algorithms is largely influenced by the system's transport delay, and their relationship is rarely considered in related work. This paper proposes a delay analysis that considers the delay of the closed-loop EEG phase-triggered TMS system as a primary factor in the validation of phase prediction algorithms. An in-silico validation using real EEG data was performed to compare the performance of commonly used algorithms. The experimental results indicate a significant influence of the total delay on the algorithm performance, and the performance ranking among algorithms varies at different levels of delay. We conclude that the delay analysis framework should be widely adopted in the design and validation of phase prediction algorithms for closed-loop EEG phase-triggered TMS systems.

Acupuncture for post-stroke depression: a systematic review and network meta-analysis

BACKGROUND

Patients with post-stroke depression (PSD) usually experience anxiety, hopelessness, and insomnia, which have a negative impact on their daily activities and post-stroke rehabilitation. Acupuncture (AC), as a minimally invasive technique, has become a popular choice for improving depression symptoms. However, it is still unclear which therapy is associated with the best outcomes for PSD. In this review, we aimed to explore the impact of AC in alleviating symptoms of PSD and to evaluate the difference in effectiveness between AC combined with pharmacotherapies and various non-pharmacotherapies.

METHODS

Six databases and three clinical trials registration platforms were searched from inception to March 2023. Randomized clinical trial comparing needle-based AC with pharmacotherapy, and other non-pharmacotherapy or invalid group were included. Two independent reviewers identified eligible studies, and collected data using a pre-made form. A Bayesian network meta-analysis was conducted to assess and compare different techniques using RStudio 3.6.0 with the package 'GEMTC' V.0.8.1. The primary outcome was the efficacy for PSD assessed by scales measuring depressive symptoms. The secondary outcomes were effectiveness for neurological function and the quality of life. The ranking probabilities for all treatment interventions was performed using the Surface Under the Cumulative Ranking curve (SUCRA). The risk of bias was assessed by using the Revised Cochrane Risk of Bias tool 2.

RESULTS

Sixty-two studies, involving 5308 participants published from 2003 to 2022, were included. The results showed that compared with western medicine (WM) (defined as pharmacotherapy for PSD), AC alone or with repetitive transcranial magnetic stimulation (RTMS), Traditional Chinese medicine (TCM) alone or with WM, were superior for alleviating depression symptoms. Compared to Usual Care, AC alone or plus other therapies could significantly decrease scores on the Hamilton Depression Rating scale. According to result of SUCRA, AC plus RTMS had the highest probability of improving depressive symptoms with a probability of 49.43%.

CONCLUSIONS

The results of this study indicate that AC alone or combined with other therapies appears to be effective in improving depression symptoms of stroke survivors. Moreover, in comparison to WM, AC alone or plus RTMS, TCM, TCM with WM, or WM, were more effective in improving depression symptoms of PSD. Also, AC with RTMS seems to be the most effective with the highest probability.

REGISTRATION

This study was registered in the International Prospective Register of Systematic Reviews (PROSPERO) database in November 2020 and updated in July 2021. The registration number is CRD42020218752.

Therapy Strategies for Late-life Depression: A Review

BACKGROUND

Depression in the elderly requires different treatment options because therapies that are commonly used for depression in younger patients show different effects later in life. Treatment options for late-life depression (LLD) are summarized in this article.

METHODS

A literature search in Medline/PubMed performed in June 2020 identified 83 relevant studies.

RESULTS

Pharmacotherapy with selective serotonin reuptake inhibitors can be an effective first-line treatment in LLD, but >50% of elderly patients do not adequately respond. Switching to other selective serotonin reuptake inhibitors or augmenting with mood stabilizers or antipsychotics is often effective in achieving a therapeutic benefit. Severely depressed patients with a high risk of suicidal behavior can be treated with electroconvulsive therapy. Psychotherapy provides a measurable benefit alone and when combined with medication.

LIMITATIONS

LLD remains an underrepresented domain in research. Paucity of data concerning the effect of specific therapies for LLD, heterogeneity in the quality of study designs, overinterpretation of results from meta-analyses, and discrepancies between study results and guideline recommendations were often noted.

CONCLUSIONS

Treating LLD is complex, but there are several treatment options with good efficacy and tolerability. Some novel pharmaceuticals also show promise as potential antidepressants, but evidence for their efficacy and safety is still limited and based on only a few trials conducted to date.

Thomas F, Battaglia F. High-frequency rTMS modulates emotional behaviors and structural plasticity in layers II/III and V of the mPFC

Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive neuromodulation technique, and it has been increasingly used as a nonpharmacological intervention for the treatment of various neurological and neuropsychiatric diseases, including depression. In humans, rTMS over the prefrontal cortex is used to induce modulation of the neural circuitry that regulates emotions, cognition, and depressive symptoms. However, the underlying mechanisms are still unknown. In this study, we investigated the effects of a short (5-day) treatment with high-frequency (HF) rTMS (15 Hz) on emotional behavior and prefrontal cortex morphological plasticity in mice. Mice that had undergone HF-rTMS showed an anti-depressant-like activity as evidenced by decreased immobility time in both the Tail Suspension Test and the Forced Swim Test along with increased spine density in both layer II/III and layer V apical and basal dendrites. Furthermore, dendritic complexity assessed by Sholl analysis revealed increased arborization in the apical portions of both layers, but no modifications in the basal dendrites branching. Overall, these results indicate that the antidepressant-like activity of HF-rTMS is paralleled by structural remodeling in the medial prefrontal cortex.

Reduced signal propagation elicited by frontal transcranial magnetic stimulation is associated with oligodendrocyte abnormalities in treatment-resistant depression

BACKGROUND

The efficacy of repetitive transcranial magnetic stimulation (rTMS) to the left dorsolateral prefrontal cortex (dlPFC) has been established in patients with treatment-resistant depression (TRD), suggesting that alterations in signal propagation from the left dlPFC to other brain regions may be linked to the pathophysiology of TRD. Alterations at the cellular level, including dysfunction of oligodendrocytes, may contribute to these network abnormalities. The objectives of the present study were to compare signal propagation from the left dlPFC to other neural networks in patients with TRD and healthy controls. We used TMS combined with electroencephalography to explore links between cell-specific gene expression and signal propagation in TRD using a virtual-histology approach.

METHODS

We examined source-level estimated signal propagation from the left dlPFC to the 7 neural networks in 60 patients with TRD and 30 healthy controls. We also calculated correlations between the interregional profiles of altered signal propagation and gene expression for 9 neural cell types derived from the Allen Human Brain Atlas data set.

RESULTS

Signal propagation from the left dlPFC to the salience network was reduced in the θ and α bands in patients with TRD (p = 0.0055). Furthermore, this decreased signal propagation was correlated with cellspecific gene expression of oligodendrocytes (p < 0.000001).

LIMITATIONS

These results show only part of the pathophysiology of TRD, because stimulation was limited to the left dlPFC.

CONCLUSION

Reduced signal propagation from the left dlPFC to the salience network may represent a pathophysiological endophenotype of TRD; this finding may be associated with reduced expression of oligodendrocytes.

Spatiotemporal Dynamics of Covert vs. Overt Emotional Face Processing in Dysphoria

People at risk of developing clinical depression exhibit attentional biases for emotional faces. To clarify whether such effects occur at an early, automatic, or at a late, deliberate processing stage of emotional processing, the present study used high-density electroencephalography during both covert and overt processing of sad, fearful, happy, and neutral expressions in healthy participants with high dysphoria (n = 16) and with low dysphoria (n = 19). A state-of-the-art non-parametric permutation-based statistical approach was then used to explore the effects of emotion, attentional task demands, and group. Behaviorally, participants responded faster and more accurately when overtly categorizing happy faces and they were slower and less accurate when categorizing sad and fearful faces, independent of the dysphoria group. Electrophysiologically, in an early time-window (N170: 140-180 ms), there was a significant main effect for the dysphoria group, with greater negative voltage for the high vs. low dysphoria group over the left-sided temporo-occipital scalp. Furthermore, there was a significant group by emotional interaction, with the high dysphoria group displaying greater negative amplitude N170 for happy than fearful faces. Attentional task demands did not influence such early effects. In contrast, in an intermediate time-window (EPN: 200-400 ms) and in a late time-window (LPP: 500-750 ms) there were no significant main effects nor interactions involving the dysphoria Group. The LPP results paralleled the behavioral results, with greater LPP voltages for sad and fearful relative to happy faces only in the overt task, but similarly so in the two dysphoria groups. This study provides novel evidence that alterations in face processing in dysphoric individuals can be seen at the early stages of face perception, as indexed by the N170, although not in the form of a typical pattern of mood-congruent attentional bias. In contrast, intermediate (EPN) and late (LPP) stages of emotional face processing appear unaffected by dysphoria. Importantly, the early dysphoria effect appears to be independent of the top-down allocation of attention, further supporting the idea that dysphoria may influence a stage of automatic emotional appraisal. It is proposed that it may be a consequence of a shift from holistic to feature-based processing of facial expressions, or may be due to the influence of negative schemas acting as a negative context for emotional facial processing.

Repetitive Transcranial Magnetic Stimulation for the Treatment of Resistant Depression: A Scoping Review

Treatment-resistant depression (TRD) is associated with significant disability, and due to its high prevalence, it results in a substantive socio-economic burden at a global level. TRD is the inability to accomplish and/or achieve remission after an adequate trial of antidepressant treatments. Studies comparing repetitive transcranial magnetic stimulation (rTMS) with electroconvulsive therapy (ECT) and pharmacotherapy have revealed evidence of the therapeutic efficacy of rTMS in TRD. These findings suggest a crucial role for rTMS in the management of TRD. This article aims to conduct a comprehensive scoping review of the current literature concerning the use of rTMS and its therapeutic efficacy as a treatment modality for TRD. PubMed, PsycINFO, Medline, Embase, and Cinahl were used to identify important articles on rTMS for TRD. The search strategy was limited to English articles within the last five years of data publication. Articles were included if they reported on a completed randomized controlled trial (RCT) of rTMS intervention for TRD. The exclusion criteria involved studies with rTMS for the treatment of conditions other than TRD, and study and experimental protocols of rTMS on TRD. In total, 17 studies were eligible for inclusion in this review. The search strategy spanned studies published in the last five years, to the date of the data search (14 February 2022). The regional breakdown of the extracted studies was North American (n = 9), European (n = 5), Asian (n = 2) and Australian (n = 1). The applied frequencies of rTMS ranged from 5 Hz to 50 Hz, with stimulation intensities ranging from 80% MT to 120% MT. Overall, 16 out of the 17 studies suggested that rTMS treatment was effective, safe and tolerated in TRD. For patients with TRD, rTMS appears to provide significant benefits through the reduction of depressive symptoms, and while there is progressive evidence in support of the same, more research is needed in order to define standardized protocols of rTMS application in terms of localization, frequency, intensity, and pulse parameters.

High-frequency repetitive transcranial magnetic stimulation at dorsolateral prefrontal cortex for migraine prevention: A systematic review and meta-analysis

OBJECTIVE

To evaluate the efficacy of high-frequency repetitive transcranial magnetic stimulation over dorsolateral prefrontal cortex as a migraine prevention by conducting a systematic review and meta-analysis.

BACKGROUND

The efficacy of high-frequency repetitive transcranial magnetic stimulation over dorsolateral prefrontal cortex as preventive migraine treatment remains debatable.

METHODS

PubMed, Scopus, CINAHL, CENTRAL, and BioMed Central databases were searched from their inception until December 2020. Randomised trials comparing high-frequency repetitive transcranial magnetic stimulation over dorsolateral prefrontal cortex with sham for migraine prevention were included. The risk of bias was assessed using the Cochrane guidelines. Headache days, pain intensity, acute medication intake, and disability were extracted as study outcomes and the mean difference with a random-effects model was used to determine the effect size.

RESULTS

Meta-analysis revealed that high-frequency repetitive transcranial magnetic stimulation over dorsolateral prefrontal cortex significantly reduced acute medication intake (Mean Difference = 9.78, p = 0.02, 95%CI: 1.60, 17.96, p = 0.02) and functional disability (Mean Difference = 8.00, p < 0.05, 95%CI: 4.21, 11.79). However, no differences were found in headache days and pain intensity reduction, although there was a slight trend favouring high-frequency repetitive transcranial magnetic stimulation.

CONCLUSION

High-frequency repetitive transcranial magnetic stimulation over dorsolateral prefrontal cortex may be effective in reducing acute medication intake and disability. However, more studies are needed to strengthen this preliminary evidence.

A Southeast Asia Consensus on the Definition and Management of Treatment-Resistant Depression

INTRODUCTION

Despite the abundance of literature on treatment-resistant depression (TRD), there is no universally accepted definition of TRD and available treatment pathways for the management of TRD vary across the Southeast Asia (SEA) region, highlighting the need for a uniform definition and treatment principles to optimize the management TRD in SEA.

METHODS

Following a thematic literature review and pre-meeting survey, a SEA expert panel comprising 13 psychiatrists with clinical experience in managing patients with TRD convened and utilized the RAND/UCLA Appropriateness Method to develop consensus-based recommendations on the appropriate definition of TRD and principles for its management.

RESULTS

The expert panel agreed that "pharmacotherapy-resistant depression" (PRD) is a more suitable term for TRD and defined it as "failure of two drug treatments of adequate doses, for 4-8 weeks duration with adequate adherence, during a major depressive episode". A stepwise treatment approach should be employed for the management of PRD - treatment strategies can include maximizing dose, switching to a different class, and augmenting or combining treatments. Non-pharmacological treatments, such as electroconvulsive therapy and repetitive transcranial magnetic stimulation, are also appropriate options for patients with PRD.

CONCLUSION

These consensus recommendations on the operational definition of PRD and treatment principles for its management can be adapted to local contexts in the SEA countries but should not replace clinical judgement. Individual circumstances and benefit-risk balance should be carefully considered while determining the most appropriate treatment option for patients with PRD.

Transcranial magnetic stimulation in the treatment of adolescent depression: a systematic review and meta-analysis of aggregated and individual-patient data from uncontrolled studies

Transcranial magnetic stimulation (TMS) is a non-invasive treatment for adolescent major depressive disorder (MDD). Existing evidence on the efficacy of TMS in adolescent MDD awaits quantitative synthesis. A systematic literature search was conducted, and data from eligible studies were synthesized using random-effects models. Treatment-covariate interactions were examined in exploratory analyses of individual-patient data (IPD). Systematic search of the literature yielded 1264 hits, of which 10 individual studies (2 randomized trials) were included for quantitative synthesis of mainly uncontrolled studies. Individual patient data (IPD) were available from five trials (all uncontrolled studies). Quantitative synthesis of aggregated data revealed a statistically significant negative overall standardized mean change (pooled SMCC = 2.04, 95% CI [1.46; 2.61], SE = 0.29, p < .001), as well as a significant overall treatment response rate (Transformed Proportion = 41.30%, 95% CI [31.03; 51.57], SE = 0.05; p < 0.001), considering data from baseline to post-treatment. Exploratory IPD analyses suggests TMS might be more effective in younger individuals and individuals with more severe depression, and efficacy might be enhanced with certain treatment modality settings, including higher number of TMS sessions, longer treatment durations, and unilateral and not bilateral stimulation. Existing studies exhibit methodological shortcomings, including small-study effects and lack of control group, blinding, and randomization-compromising the credibility of the present results. To date, two randomized controlled trials on TMS in adolescent depression have been published, and the only large-scale randomized trial suggests TMS is not more effective than sham stimulation. Future large-scale, randomized, and sham-controlled trials are warranted. Future trials should ensure appropriate selection of patients for TMS treatment and guide precision medicine approaches for stimulation protocols.

Repetitive Transcranial Magnetic Stimulation for Comorbid Major Depressive Disorder and Alcohol Use Disorder

Major depressive disorder (MDD) and alcohol use disorder (AUD) are leading causes of disability, and patients are frequently affected by both conditions. This comorbidity is known to confer worse outcomes and greater illness severity. Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive neuromodulation method that has demonstrated antidepressant effects. However, the study of rTMS for patients with MDD and commonly associated comorbidities, such as AUD, has been largely overlooked, despite significant overlap in clinical presentation and neurobiological mechanisms. This narrative review aims to highlight the interrelated aspects of the literature on rTMS for MDD and rTMS for AUD. First, we summarize the available evidence on the effectiveness of rTMS for each condition, both most studied through stimulation of the dorsolateral prefrontal cortex (DLPFC). Second, we describe common symptom constructs that can be modulated by rTMS, such as executive dysfunction, that are transdiagnostic across these disorders. Lastly, we describe promising approaches in the personalization and optimization of rTMS that may be applicable to both AUD and MDD. By bridging the gap between research efforts in MDD and AUD, rTMS is well positioned to be developed as a treatment for the many patients who have both conditions concurrently.

Transcranial direct current and transcranial magnetic stimulations for chronic pain

PURPOSE OF REVIEW

Chronic pain is debilitating and difficult to treat with pharmacotherapeutics alone. Consequently, exploring alternative treatment methods for chronic pain is essential. Noninvasive brain stimulation techniques, such as transcranial direct current stimulation (tDCS) and transcranial magnetic stimulation (TMS) are increasingly being investigated for their neuropharmacological effects in the treatment of chronic pain. This review aims to examine and evaluate the present state of evidence regarding the use of tDCS and TMS in the treatment of chronic pain.

RECENT FINDINGS

Despite conflicting evidence in the early literature, evidence from recent rigorous research supports the use of tDCS and TMS in treating chronic pain conditions. For both tDCS and TMS, standardized stimulation parameters have been identified with the recommendation for repeated maintenance stimulation to ensure that the analgesic effect is sustained beyond discontinuation of therapy.

SUMMARY

Due to a lack of defined stimulation protocols, early findings on the efficacy of tDCS and TMS are mixed. Although the application of tDCS and TMS as pain relief approaches is still in its early stages, the introduction of standardized stimulation protocols is paving the way for more robust and informed research.

Hypomanic/manic switch after transcranial magnetic stimulation in mood disorders: A systematic review and meta-analysis

BACKGROUND

Nowadays there is an increasing use of transcranial magnetic stimulation (TMS) both in neurological and psychiatric fields. After Food and Drug Administration approval of TMS for the therapy of treatment-resistant depression, TMS has been widely used in the context of mood disorders (MD). However, growing reports regarding the possibility of developing hypomanic/manic switch (HMS) have generated concern regarding its use in MDs.

AIM

To investigate the actual risk of developing HMS due to TMS in the treatment of MD.

METHODS

We led our research on PubMed, Scopus and Web of Science on March 22, 2020, in accordance to the PRISMA guidelines for systematic review. Only double blind/single blind studies, written in English and focused on the TMS treatment of MD, were included. A meta-analysis of repetitive TMS protocol studies including HMS was conducted using RevMan 5.4 software. The assessment of Risk of Bias was done using Cochrane risk of bias tool. This protocol was registered on PROSPERO with the CRD42020175811 code.

RESULTS

Twenty-five studies were included in our meta-analysis: Twenty-one double blind randomized controlled trials (RCT) and four single blind-RCT (no. of subjects involved in active stimulation = 576; no. of subjects involved in sham protocol = 487). The most frequently treated pathology was major depressive episode/major depressive disorder, followed by resistant depression, bipolar depression and other MD. The majority of the studies used a repetitive TMS protocol, and the left dorsolateral prefrontal cortex was the main target area. Side effects were reported in eight studies and HMS (described as greater energy, insomnia, irritability, anxiety, suicidal attempt) in four studies. When comparing active TMS vs sham treatment, the risk of developing HMS was not significantly different between conditions.

CONCLUSION

Applying the most usual protocols and the appropriate precautionary measures, TMS seems not to be related to HMS development.

Novel Therapeutic Approaches for Alzheimer's Disease: An Updated Review

Alzheimer’s disease (AD) is a progressive neurodegenerative disease and accounts for most cases of dementia. The prevalence of AD has increased in the current rapidly aging society and contributes to a heavy burden on families and society. Despite the profound impact of AD, current treatments are unable to achieve satisfactory therapeutic effects or stop the progression of the disease. Finding novel treatments for AD has become urgent. In this paper, we reviewed novel therapeutic approaches in five categories: anti-amyloid therapy, anti-tau therapy, anti-neuroinflammatory therapy, neuroprotective agents including N-methyl-D-aspartate (NMDA) receptor modulators, and brain stimulation. The trend of therapeutic development is shifting from a single pathological target to a more complex mechanism, such as the neuroinflammatory and neurodegenerative processes. While drug repositioning may accelerate pharmacological development, non-pharmacological interventions, especially repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS), also have the potential for clinical application. In the future, it is possible for physicians to choose appropriate interventions individually on the basis of precision medicine.

Loss of Cav1.2 channels impairs hippocampal theta burst stimulation-induced long-term potentiation

CACNA1 C, which codes for the Ca_v1.2 isoform of L-type Ca²⁺ channels (LTCCs), is a prominent risk gene in neuropsychiatric and neurodegenerative conditions. A role forLTCCs, and Ca_v1.2 in particular, in transcription-dependent late long-term potentiation (LTP) has long been known. Here, we report that elimination of Ca_v1.2 channels in glutamatergic neurons also impairs theta burst stimulation (TBS)-induced LTP in the hippocampus, known to be transcription-independent and dependent on N-methyl D-aspartate receptors (NMDARs) and local protein synthesis at synapses. Our expansion of the established role of Ca_v1.2channels in LTP broadens understanding of synaptic plasticity and identifies a new cellular phenotype for exploring treatment strategies for cognitive dysfunction.

PAID study design on the role of PKC activation in immune/inflammation-related depression: a randomised placebo-controlled trial protocol

Background

Inflammation that is mediated by microglia activation plays an important role in the pathogenesis of depression. Microglia activation can lead to an increase in the levels of proinflammatory cytokines, including TNF-α, which leads to neuronal apoptosis in the specific neural circuits of some brain regions, abnormal cognition and treatment-resistant depression (TRD). Protein kinase C (PKC) is a key regulator of the microglia activation process. We assume that the abnormality in PKC might result in abnormal microglia activation, neuronal apoptosis, significant changes in emotional and cognitive neural circuits, and TRD. In the current study, we plan to target at the PKC signal pathway to improve the TRD treatment outcome.

Methods and analysis

This is a 12-week, ongoing, randomised, placebo-controlled trial. Patients with TRD (N=180) were recruited from Shanghai Mental Health Center, Shanghai Jiao Tong University. Healthy control volunteers (N=60) were recruited by advertisement. Patients with TRD were randomly assigned to 'escitalopram+golimumab (TNF-α inhibitor)', 'escitalopram+calcium tablet+vitamin D (PKC activator)' or 'escitalopram+placebo' groups. We define the primary outcome as changes in the 17-item Hamilton Depression Rating Scale (HAMD-17). The secondary outcome is defined as changes in anti-inflammatory effects, cognitive function and quality of life.

Discussion

This study might be the first randomised, placebo-controlled trial to target at the PKC signal pathway in patients with TRD. Our study might help to propose individualised treatment strategies for depression.

Trial registration number

The trial protocol is registered with ClinicalTrials.gov under protocol ID 81930033 and ClinicalTrials.gov ID NCT04156425.

A happiness magnet? Reviewing the evidence for repetitive transcranial magnetic stimulation in major depressive disorder

OBJECTIVES

First, to conduct a historical review of the evidence for repetitive transcranial magnetic stimulation (rTMS) for major depressive disorder and determine a clinical algorithm. Second, to identify opportunities for research.

METHODS

Literature searches were conducted of the MEDLINE database, UpToDate and the Australian National University Library SuperSearch from 1 January 2000 to 30 September 2019. The search terms used were 'transcranial magnetic stimulation', 'major depressive disorder' and 'depression'.

RESULTS

There were 24 meta-analyses identified, demonstrating a clear clinical effect. Left high-frequency rTMS had the most evidence. Ideal clinical parameters and study design were explored.

CONCLUSION

Use of rTMS for some patients with depression is justified. Open research questions include the comparative efficacy of right low-frequency and bilateral stimulation, the role of rTMS in medication-naïve patients, and maintenance of effect.

Experimental Therapeutics in Treatment-Resistant Major Depressive Disorder

Treatment-Resistant Depression (TRD) patients remain a challenging sub-division of patients with Major Depressive Disorder (MDD) in day to day clinical practice. As with any diagnostic condition, comprehensive evaluation, exclusion of other psychiatric conditions, assessment of co-morbid medical and psychiatric illnesses and psychosocial stressors are the keys to appropriate diagnosis and subsequent management. There are various management options available for the treatment of MDD, however, about 30% of the patients fail to achieve full remission of symptoms despite multiple trials and belong to this sub-category of MDD. This article brings forth discussion of other non-conventional medication and non-medication treatment alternatives that merit exploration of their efficacy in TRD. Many of the proposed novel medications and other treatment modalities such as Deep Brain Stimulation, exercise, yoga are already used for other medical and psychiatric disorders and have some evidence suggesting their potential benefits in TRD in conjunction with conventional medications or even as monotherapy. Nevertheless, more research is needed in this direction to establish effectiveness.

Three-dimensional optical imaging of brain activation during transcranial magnetic stimulation

Repetitive transcranial magnetic stimulation (rTMS) of the brain is an effective clinical treatment for psychiatric disorders. Noninvasive neuroimaging during rTMS allows visualization of cortical brain activations and responses, and it is a potential tool for investigating the neurophysiological response occurring actively during stimulation. In this paper, we present a fast diffuse optical tomography (DOT) approach for three-dimensional brain mapping of hemodynamics during rTMS. Eight healthy subjects were enrolled in the study. These subjects received 10 Hz stimulation with 80%and 100%of resting motor threshold (rMT), respectively, for 4 seconds for each stimulation. Significant hemodynamic activation was observed in all cases with the strongest response when 100%rMT stimulation was applied. This work demonstrates that fast DOT has the potential to become a powerful tool for noninvasive three-dimensional imaging of the brain during rTMS.

Mechanisms of repetitive transcranial magnetic stimulation for anti-depression: Evidence from preclinical studies

This review summarizes the anti-depressant mechanisms of repetitive transcranial magnetic stimulation in preclinical studies, including anti-inflammatory effects mediated by activation of nuclear factor-E2-related factor 2 signaling pathway, anti-oxidative stress effects, enhancement of synaptic plasticity and neurogenesis via activation of the endocannabinoid system and brain derived neurotrophic factor signaling pathway, increasing the content of monoamine neurotransmitters via inhibition of Sirtuin 1/monoamine oxidase A signaling pathway, and reducing the activity of the hypothalamic-pituitary-adrenocortical axis. We also discuss the shortcomings of transcranial magnetic stimulation in preclinical studies such as inaccurate positioning, shallow depth of stimulation, and difficulty in elucidating the neural circuit mechanism up- and down-stream of the stimulation target brain region.

Improving Mental Health Services: A 50-Year Journey from Randomized Experiments to Artificial Intelligence and Precision Mental Health

This conceptual paper describes the current state of mental health services, identifies critical problems, and suggests how to solve them. I focus on the potential contributions of artificial intelligence and precision mental health to improving mental health services. Toward that end, I draw upon my own research, which has changed over the last half century, to highlight the need to transform the way we conduct mental health services research. I identify exemplars from the emerging literature on artificial intelligence and precision approaches to treatment in which there is an attempt to personalize or fit the treatment to the client in order to produce more effective interventions.

Antidepressant efficacy and side effect burden: an updated guide for clinicians

Antidepressant treatment has been evolving and changing since the 1950s following the discovery of the classic antidepressant treatments including tricyclic antidepressants and monoamine oxidase inhibitors. The heterogeneity of the disorder became apparent in the beginning when individuals remained symptomatic despite medication compliance. This spurred further research in order to understand the neurobiology underlying the disorder. Subsequently, newer medications were designed to target specific neurotransmitters and areas of the brain involved in symptom development and maintenance. Our original review article looked at both classic and modern antidepressant medications used in the treatment of major depressive disorder. This manuscript is an update to the original review and serves to provide clinicians with information about novel antidepressant medications, augmentation strategies with atypical antipsychotics, over-the-counter medications, as well as nonpharmaceutical treatments that should be considered when treating each individual patient who remains symptomatic despite treatment efforts.