Neuromodulation for treatment-refractory major depressive disorder

A preliminary comparison of the clinical efficacy of repetitive transcranial magnetic stimulation with facial feature point localization and navigated localization in the treatment of depression

OBJECTIVE

To compare the clinical efficacy of repetitive transcranial magnetic stimulation (rTMS) under facial feature point localization (FFP) localization versus neuro-navigated localization for depression.

METHODS

42 depressed patients were randomly assigned to two groups, received 10 Hz rTMS twice daily for 10 consecutive days. Relevant symptom scale assessments were conducted by professionals at baseline, after 10 sessions, and at the end of treatment. The confidence interval was calculated at a 95 % confidence level. The significant level was set at p < 0.05.

RESULTS

The absolute change in HAMD total score from baseline to the end of therapy did not differ significantly between the groups. The generalized estimating equation showed the main effect of time was significant, which showed improvement of depressive symptoms in patients throughout treatment. Upon completion of the treatment, FFP group showed a response rate of 64.7 % and a remission rate of 29.4 %, whereas the navigated group exhibited a response rate of 61.1 % and a remission rate of 44.4 %. There was no serious adverse events occurred during the treatment process. Throughout the study, no intervention was made on the normal medication treatment, and some patients had concomitant antidepressants and benzodiazepines.

CONCLUSION

There was no significant difference in clinical efficacy between FFP localization and navigation localization in the small-sample study. However, due to the limited sample size and lack of rigorous non-inferiority testing, the superiority of one over the other remains uncertain, necessitating rigorous experimental design to validate the efficacy difference between the two localization methods.

N100 as a response prediction biomarker for accelerated 1 Hz right DLPFC-rTMS in major depression

BACKGROUND AND OBJECTIVE

Repetitive transcranial magnetic stimulation (rTMS) is a safe and effective treatment for major depressive disorder (MDD); however, this treatment currently lacks reliable biomarkers of treatment response. TMS-evoked potentials (TEPs), measured using TMS-electroencephalography (TMS-EEG), have been suggested as potential biomarker candidates, with the N100 peak being one of the most promising. This study investigated the association between baseline N100 amplitude and 1 Hz right dorsolateral prefrontal cortex (R-DLPFC) accelerated rTMS (arTMS) treatment in MDD.

METHODS

Baseline TMS-EEG sessions were performed for 23 MDD patients. All patients then underwent 40 sessions of 1 Hz R-DLPFC (F4) arTMS over 5 days and a follow-up TMS-EEG session one week after the end of theses arTMS sessions.

RESULTS

Baseline N100 amplitude at F4 showed a strong positive association (p < .001) with treatment outcome. The association between the change in N100 amplitude (baseline to follow-up) and treatment outcome did not remain significant after Bonferroni correction (p = .06, corrected; p = .03, uncorrected). Furthermore, treatment responders had a significantly larger mean baseline F4 TEP amplitude during the N100 time frame compared to non-responders (p < .001). Topographically, after Bonferroni correction, F4 is the only electrode at which its baseline N100 amplitude showed a significant positive association (p < .001) with treatment outcome.

LIMITATIONS

Lack of control group and auditory masking.

CONCLUSION

Baseline N100 amplitude showed a strong association with treatment outcome and thus demonstrated great potential to be utilized as a cost-effective and widely adoptable biomarker of rTMS treatment in MDD.

The effect of repetitive transcranial magnetic stimulation on the Hamilton Depression Rating Scale-17 criterion in patients with major depressive disorder without psychotic features: a systematic review and meta-analysis of intervention studies

AIM

In line with the publication of clinical information related to the therapeutic process of repetitive transcranial magnetic stimulation (rTMS) and the updating of relevant treatment guidelines, the present meta-analysis study was designed and conducted to determine the effect of repetitive transcranial magnetic stimulation (rTMS) on the Hamilton Depression Rating Scale-17 (HDRS-17) criterion in patients with major depressive disorder (MDD) without psychotic features.

METHODS

In this study, a systematic search was conducted in electronic databases such as PubMed [Medline], Scopus, Web of Science, Embase, Ovid, Cochrane Library, and ClinicalTrials. gov using relevant keywords. The search period in this study was from January 2000 to January 2022, which was updated until May 2023. Randomized controlled trials (RCTs) that determined the effect of repetitive transcranial magnetic stimulation (rTMS) on the Hamilton Depression Rating Scale-17 (HDRS-17) criterion in patients with major depressive disorder (MDD) without psychotic features were included in the analysis. The quality of the included RCTs was assessed using the Cochrane Risk of Bias checklist. Statistical analyses were performed using STATA (Version 16) and RevMan (Version 5).

RESULTS

Following the combination of results from 16 clinical trial studies in the present meta-analysis, it was found that the mean Hamilton Depression Rating Scale-17 (HDRS-17) in patients with major depressive disorder (MDD) decreases by an average of 1.46 units (SMD: -1.46; % 95 CI: -1.65, -1.27, I square: 45.74%; P heterogeneity: 0.56). Subgroup analysis results indicated that the standardized mean difference of Hamilton Depression Rating Scale-17 (HDRS-17) varied based on the number of treatment sessions: patients receiving 10 or fewer repetitive transcranial magnetic stimulation (rTMS) sessions showed a mean Hamilton Depression Rating Scale-17 (HDRS-17) reduction of 2.60 units (SMD: -2.60; % 95 CI: -2.86, -2.33, I square: 55.12%; P heterogeneity: 0.55), while those receiving 11 to 20 sessions showed a mean Hamilton Depression Rating Scale-17 (HDRS-17) reduction of 0.28 units (SMD: -0.28; % 95 CI: -0.65, -0.09, I square: 39.91%; P heterogeneity: 0.89).

CONCLUSION

In conclusion, our meta-analysis demonstrates the efficacy of repetitive transcranial magnetic stimulation (rTMS) in reducing depressive symptoms in major depressive disorder (MDD) patients. The complex results of subgroup analysis revealed insight on the possible benefits of a more focused strategy with fewer sessions, as well as the impact of treatment session frequency. These findings add to our understanding of repetitive transcranial magnetic stimulation (rTMS) as a therapeutic intervention for the treatment of major depressive illnesses.

A randomized sham-controlled trial of high-dosage accelerated intermittent theta burst rTMS in major depression: study protocol

BACKGROUND

Intermittent theta burst stimulation (iTBS), a novel form of repetitive transcranial magnetic stimulation (rTMS), can be administered in 1/10th of the time of standard rTMS (~ 3 min vs. 37.5 min) yet achieves similar outcomes in depression. The brief nature of the iTBS protocol allows for the administration of multiple iTBS sessions per day, thus reducing the overall course length to days rather than weeks. This study aims to compare the efficacy and tolerability of active versus sham iTBS using an accelerated regimen in patients with treatment-resistant depression (TRD). As a secondary objective, we aim to assess the safety, tolerability, and treatment response to open-label low-frequency right-sided (1 Hz) stimulation using an accelerated regimen in those who do not respond to the initial week of treatment.

METHODS

Over three years, approximately 230 outpatients at the Centre for Addiction and Mental Health and University of British Columbia Hospital, meeting diagnostic criteria for unipolar MDD, will be recruited and randomized to a triple blind sham-controlled trial. Patients will receive five consecutive days of active or sham iTBS, administered eight times daily at 1-hour intervals, with each session delivering 600 pulses of iTBS. Those who have not achieved response by the week four follow-up visit will be offered a second course of treatment, regardless of whether they initially received active or sham stimulation.

DISCUSSION

Broader implementation of conventional iTBS is limited by the logistical demands of the current standard course consisting of 4-6 weeks of daily treatment. If our proposed accelerated iTBS protocol enables patients to achieve remission more rapidly, this would offer major benefits in terms of cost and capacity as well as the time required to achieve clinical response.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04255784.

Cardiovascular biomarkers of response to accelerated low frequency repetitive transcranial magnetic stimulation in major depression

BACKGROUND AND OBJECTIVE

Repetitive transcranial magnetic stimulation (rTMS) is an effective and safe treatment for major depressive disorder (MDD). rTMS is in need of a reliable biomarker of treatment response. High frequency (HF) dorsolateral prefrontal cortex (DLPFC) rTMS has been reported to induce significant changes in the cardiac activity of MDD patients. Low frequency DLPFC rTMS has many advantages over HF-DLPFC rTMS and thus this study aims to further investigate the effect of low frequency 1 Hz right hemisphere (R)-DLPFC rTMS on the cardiac activity of MDD patients, as well as the potential of using electrocardiogram (ECG) parameters as biomarkers of treatment outcome.

METHODS

Baseline ECG sessions were performed for 19 MDD patients. All patients then underwent 40 sessions of accelerated 1 Hz R-DLPFC rTMS one week after the baseline session.

RESULTS

Heart rate (HR) significantly decreased from the resting period to the first and third minute of the 1 Hz R-DLPFC rTMS period. Resting HR was found to have a significant negative association with treatment outcome. Prior to Bonferroni correction, HR during stimulation and the degree of rTMS-induced HR reduction were significantly negatively associated with treatment outcome. No significant changes were observed for the heart rate variability (HRV) parameters.

LIMITATIONS

Sample size (n = 19); the use of electroencephalography equipment for ECG; lack of respiration monitoring; relatively short recording duration for HRV parameters.

CONCLUSION

This novel study provides further preliminary evidence that ECG may be utilized as a biomarker of rTMS treatment response in MDD.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04376697.

Effect of high frequency versus theta-burst repetitive transcranial magnetic stimulation on suicidality in patients with treatment-resistant depression

OBJECTIVE

To investigate the effect of 10 Hz repetitive transcranial magnetic stimulation (rTMS) and intermittent theta-burst stimulation (iTBS) on suicidality in patients with treatment-resistant depression (TRD).

METHODS

We used data from a three-site randomized clinical trial comparing 10 Hz rTMS and iTBS applied to the left dorsolateral prefrontal cortex (DLPFC) in patients with TRD. We compared the effect of 10Hz rTMS and iTBS on suicidality as measured by the suicide item of the Hamilton Depression Rating Scale 17-item (HDRS-17).

RESULTS

Suicidality remitted in 71 (43.7%) participants randomized to 10Hz stimulation and 91 (49.1%) participants randomized to iTBS, without a significant difference between the proportions in the two groups (Χ²  = 0.674, df = 1, p = 0.4117). There was a significant correlation between change in suicidality and change in depression severity for both modalities (10 Hz, Pearson's r = 0.564; iTBS, Pearson's r = 0.502), with a significantly larger decrease in depression severity for those in whom suicidality remitted compared to those in whom it did not (t = 10.912, df = 276.8, p < 0.001).

CONCLUSIONS

Both 10 Hz and iTBS rTMS were effective in reducing suicidality in TRD. Future trials of iTBS for depression should include discrete measures of suicidality.

Non-invasive brain stimulation combined with psychosocial intervention for depression: a systematic review and meta-analysis

OBJECTIVES

This review investigates the efficacy and safety of non-invasive brain stimulation (NIBS) combined with psychosocial intervention on depressive symptoms.

MATERIALS AND METHODS

We systematically searched five electronic databases from their inception to June 2021: PubMed, Embase, PsycINFO, Web of Science, and Medline. Randomized or non-randomized clinical trials in which NIBS plus psychosocial intervention was compared to control conditions in people with depressive symptoms were included.

RESULTS

A total of 17 eligible studies with 660 participants were included. The meta-analysis results showed that NIBS combined with psychosocial therapy had a positive effect on moderate to severe depression ([SMD = - 0.46, 95%CI (- 0.90, - 0.02), I² = 73%, p < .01]), but did not significantly improve minimal to mild depression ([SMD = - 0.12, 95%CI (- 0.42, 0.18), I² = 0%, p = .63]). Compared with NIBS alone, the combination treatment had a significantly greater effect in alleviating depressive symptoms ([SMD = - 0.84, 95%CI (- 1.25, - 0.42), I² = 0%, p = .93]). However, our results suggested that the pooled effect size of ameliorating depression of NIBS plus psychosocial intervention had no significant difference compared with the combination of sham NIBS [SMD = - 0.12, 95%CI (- 0.31, 0.07), I² = 0%, p = .60] and psychosocial intervention alone [SMD = - 0.97, 95%CI (- 2.32, 0.38), I² = 72%, p = .01].

CONCLUSION

NIBS when combined with psychosocial intervention has a significant positive effect in alleviating moderately to severely depressive symptoms. Further well-designed studies of NIBS combined with psychosocial intervention on depression should be carried out to consolidate the conclusions and explore the in-depth underlying mechanism.

rTMS Therapy Reduces Hypofrontality in Patients With Depression as Measured by fNIRS

Multichannel functional near-infrared spectroscopy (fNIRS) is a tool used to capture changes in cerebral blood flow. A consistent result for depression is a decrease in blood flow in the frontal cortex leading to hypofrontality, which indicates multidomain functional impairment. Repetitive transcranial magnetic stimulation (rTMS) and elective convulsive therapy (ECT) are alternatives to antidepressant drugs for the treatment of depression but the underlying mechanism is yet to be elucidated. The aim of the current study was to evaluate cerebral blood flow using fNIRS following rTMS treatment in patients with depression. The cerebral blood flow of 15 patients with moderate depression after rTMS treatment was measured using fNIRS. While there was clear hypofrontality during pre-treatment (5 ± 2.5), a notable increase in oxygenated hemoglobin was observed after 30 sessions with rTMS (50 ± 15). This increased blood flow was observed in a wide range of channels in the frontal cortex; however, the centroid values were similar between the treatments. Increased blood flow leads to the activation of neuronal synapses, as noted with other neuromodulation treatments such as electroconvulsive therapy. This study describes the rTMS-induced modulation of blood oxygenation response over the prefrontal cortex in patients with depression, as captured by fNIRS. Future longitudinal studies are needed to assess cerebral blood flow dynamics during rTMS treatment for depression.

A randomized sham controlled comparison of once vs twice-daily intermittent theta burst stimulation in depression: A Canadian rTMS treatment and biomarker network in depression (CARTBIND) study

BACKGROUND

Intermittent theta burst stimulation (iTBS) is a newer form of repetitive transcranial magnetic stimulation (rTMS) for patients with treatment resistant depression (TRD). Applying multiple daily iTBS sessions may enable patients to achieve remission more rapidly.

OBJECTIVE

We compared the efficacy and tolerability of a twice-daily versus once-daily iTBS protocol in patients with TRD. We hypothesized that twice-daily iTBS would result in a greater improvement in depression scores compared to once-daily iTBS.

METHODS

208 participants (131 females) with TRD were randomized to receive either iTBS (600 pulses) delivered twice-daily with a 54-min interval between treatments or once-daily (1200 pulses) with 1 sham treatment with the same interval between treatments, to ensure equal levels of daily therapeutic contact and blinding of patients and raters. The primary outcome measure was change in depression scores on the Hamilton Rating Scale for Depression (HRSD-17) after 10 days of treatment and 30 days of treatments.

RESULTS

HRSD-17 scores improved in both the twice-daily and once-daily iTBS groups; however, these improvements did not significantly differ between the two groups at either the 10-day or 30-day timepoints. Response and remission rates were low (<10%) in both groups after 10 days and consistent with prior reports at 30 days; these rates did not differ between the treatment groups.

CONCLUSIONS

These results suggest that twice-daily iTBS does not accelerate response to iTBS and is not different from once-daily treatment in terms of improving depressive symptoms in patients with TRD. Clinicaltrials.gov ID: NCT02729792 (https://clinicaltrials.gov/ct2/show/NCT02729792).

Emotion-Attention Interaction in the Right Hemisphere

Hemispheric asymmetries in affective and cognitive functions have been extensively studied. While both cerebral hemispheres contribute to most affective and cognitive processes, neuroscientific literature and neuropsychological evidence support an overall right hemispheric dominance for emotion, attention and arousal. Emotional stimuli, especially those with survival value such as threat, tend to be prioritized in attentional resource competition. Arousing unpleasant emotional stimuli have prioritized access, especially to right-lateralized attention networks. Interference of task performance may be observed when limited resources are exhausted by task- and emotion-related processing. Tasks that rely on right hemisphere-dependent processing, like attending to the left visual hemifield or global-level visual features, are especially vulnerable to interference due to attention capture by unpleasant emotional stimuli. The aim of this review is to present literature regarding the special role of the right hemisphere in affective and attentional brain processes and their interaction. Furthermore, clinical and technological implications of this interaction will be presented. Initially, the effects of focal right hemisphere lesion or atrophy on emotional functions will be introduced. Neurological right hemisphere syndromes including aprosodia, anosognosia and neglect, which further point to the predominance of the intact right hemisphere in emotion, attention and arousal will be presented. Then there will be a brief review of electrophysiological evidence, as well as evidence from patients with neglect that support attention capture by emotional stimuli in the right hemisphere. Subsequently, experimental work on the interaction of emotion, attention and cognition in the right hemispheres of healthy subjects will be presented. Finally, clinical implications for better understanding and assessment of alterations in emotion-attention interaction due to brain disorder or treatment, such as neuromodulation, that impact affective brain functions will be discussed. It will be suggested that measuring right hemispheric emotion-attention interactions may provide basis for novel biomarkers of brain health. Such biomarkers allow for improved diagnostics in brain damage and disorders and optimized treatments. To conclude, future technological applications will be outlined regarding brain physiology-based measures that reflect engagement of the right hemisphere in affective and attentional processes.

Last Resort Interventions?: A Qualitative Study of Psychiatrists' Experience with and Views on Psychiatric Electroceutical Interventions

Psychiatrists play an important role in providing access to psychiatric electrical interventions (PEIs) such as electroconvulsive therapy (ECT) and transcranial magnetic stimulation (TMS). As such, their views on these procedures likely influence whether they refer or provide these types of treatments for their clinically depressed patients. Despite this, scholars have too infrequently examined psychiatrists' views about specific PEIs and have not yet examined their views across different PEIs. To gain insight into psychiatrists' views about PEIs, we conducted a qualitative study based on semi-structured interviews with 16 psychiatrists in Michigan. The majority of psychiatrists had a positive attitude towards PEIs in general. One-third reported cautionary attitudes towards PEIs; they did not reject the interventions but were skeptical of their effectiveness or felt they needed further development. The majority of psychiatrists consider ECT and TMS to be viable therapies that they would discuss with their patients after several failed medication trials. There was a lack of knowledge about surgical PEIs, such as deep brain stimulation. This study provides insights into how psychiatrists perceive PEIs. While broadly positive attitudes exist, this research highlights certain challenges, particularly lack of knowledge and ambiguity about the use of PEIs.

Locations for noninvasive brain stimulation in treating depressive disorders: A combination of meta-analysis and resting-state functional connectivity analysis

OBJECTIVE

Many noninvasive brain stimulation techniques have been applied to treat depressive disorders. However, the target brain region in most noninvasive brain stimulation studies is the dorsolateral prefrontal cortex. Exploring new stimulation locations may improve the efficacy of noninvasive brain stimulation for depressive disorders. We aimed to explore potential noninvasive brain stimulation locations for depressive disorders through a meta-analysis and a functional connectivity approach.

METHODS

We conducted a meta-analysis of 395 functional magnetic resonance imaging studies to identify depressive disorder-associated brain regions as regions of interest. Then, we ran resting-state functional connectivity analysis with three different pipelines in 40 depression patients to find brain surface regions correlated with these regions of interest. The 10-20 system coordinates corresponding to these brain surface regions were considered as potential locations for noninvasive brain stimulation.

RESULTS

The 10-20 system coordinates corresponding to the bilateral dorsolateral prefrontal cortex, bilateral inferior frontal gyrus, medial prefrontal cortex, supplementary motor area, bilateral supramarginal gyrus, bilateral primary motor cortex, bilateral operculum, left angular gyrus and right middle temporal gyrus were identified as potential locations for noninvasive brain stimulation in depressive disorders. The coordinates were: posterior to F3, posterior to F4, superior to F3, posterior to F7, anterior to C4, P3, midpoint of F7-T3, posterior to F8, anterior to C3, midpoint of Fz-Cz, midpoint of Fz-Fp1, anterior to T4, midpoint of C3-P3, and anterior to C4.

CONCLUSION

Our study identified several potential noninvasive brain stimulation locations for depressive disorders, which may serve as a basis for future clinical investigations.

Functional electrical stimulation of the facial muscles to improve symptoms in individuals with major depressive disorder: pilot feasibility study

Background

Currently, the mainstay of treatment in patients diagnosed with major depressive disorder (MDD) requiring medical attention is second generation anti-depressants. However, about 40% of patients treated with second-generation anti-depressants do not respond to initial treatment and approximately 70% do not achieve remission during the first-step treatment. There are a few non-pharmacological options available, but none have shown consistently positive results. There is a need for an intervention that is relatively easy to administer, produces consistently positive results and is associated with minimal side effects. In the current study, we assessed the feasibility of using transcutaneous Functional Electrical Stimulation Therapy (FEST) of the facial muscles, as a tool for improving depressive symptoms in individuals with MDD.

Results

Ten (10) individuals with moderate to severe MDD received three FEST sessions/week for a minimum of 10 to a maximum of 40 sessions. All study participants completed the required 10 therapy sessions, and 5 of the 10 participants completed additional 30 (totalling 40) FEST sessions. There were no adverse events or concerns regarding compliance to therapy. We found statistically significant improvements on Hamilton Rating Scale for Depression (HDS) and Inventory of Depressive Symptomatology (IDS) measures. However, no significant improvements were found on Positive and Negative Affect Scale and 10-point Visual Analogue Scale scales. Participants reported improvements in sleeping patterns, and this correlated with statistically significant improvements on sleep parameters of HDS and IDS measures.

Conclusion

This study indicates that facial FEST is an acceptable, practical, and safe treatment in individuals with MDD. We provide preliminary evidence to show improvements in depressive symptoms following a minimum of 10 FEST sessions.

Do Relational and Self-Definitional Traits Influence Deep Brain Stimulation Device Preference?

Personality psychodynamics have been shown to influence individual responses to psychiatric treatments, including medication. Increasingly, neuromodulation therapies have become available for severe and treatment-resistant depression. This study aims to evaluate patient response to an implanted neurostimulator battery within the framework of relational versus self-definitional personality traits. Relational development is interpersonally oriented and disruptions along this pathway lead to dependency on others for a sense of security and self-worth. Self-definitional development is characterized by autonomy strivings and disruptions lead to self-critical feelings of failing to meet expectations. Patients drawn from a larger study of deep brain stimulation (DBS) for treatment-resistant depression were switched from a non-rechargeable to a rechargeable battery type to maintain stimulation therapy. This switch entailed taking greater personal responsibility for device maintenance and allowed for fewer battery replacement surgeries. Twenty-six patients completed the Depressive Experiences Questionnaire (DEQ) and a questionnaire surveying their preference for DBS battery type. Results show that the DEQ dependency subscale, and more specifically the neediness component of the subscale, is associated with patient preference for the non-rechargeable battery. This suggests that individuals with higher relational needs prefer treatment options that increase contact with and need for medical caregivers and may prioritize this aspect of an intervention over alternative considerations. In contrast, individuals with more self-critical personality traits did not have a battery type preference, indicating that self-definitional needs were not predictive of battery preference. The link between an individual's personality psychodynamics and response to biomedical interventions, including neuromodulation and treatments that incorporate medical devices, deserves further attention.

Anti-Suicidal Efficacy of Repetitive Transcranial Magnetic Stimulation in Depressive Patients: A Retrospective Analysis of a Large Sample

Background: Suicide is a major public health problem. About 90% of suicide victims have one or more major psychiatric disorder, with a reported 20-fold increased risk for suicide in patients with affective disorders in comparison with healthy subjects. Repetitive transcranial magnetic stimulation (rTMS) has been established as an effective alternative or adjunctive treatment option for patients with depressive disorders, but little is known about its effects on suicide risk. Objective: For the assessment of the effectiveness of rTMS on suicidal ideation and behaviors, we performed a retrospective analysis of a large sample of patients with depressive disorders, who were treated with rTMS. Methods: We analyzed the records of 711 TMS in- and out-patients with depressive affective disorders in a tertiary referral hospital between 2002 and 2017. Out of these patients we were able to collect Hamilton depression rating scale (HAMD) data of 332 patients (180 females, 152 males; age range 20 to 79 years; mean age 47.3 ± 12.3) for which we analyzed the change of suicidal ideation by using item 3 (suicidality) of HAMD. Results: Out of all 711 patients treated with rTMS for their depression, one patient (0.1%) committed suicide during the TMS treatment. In the statistical analysis of the subsample with 332 patients there was an overall amelioration of depressive symptoms accompanied by a significant decrease in the suicidality item with a medium effect size. Decrease in suicidality was not inferior to changes in other items as indicated by effect sizes. Forty-seven percent of patients showed an amelioration in suicidality, 41.3% of patients did not show a change in their suicidality's scores, and 11.7% of patients showed an increase in suicidality's scores from baseline to final rating. Correlation of item 3 (suicidality) and item 7 (drive) demonstrated a significant positive association, revealing improved drive with a parallel decreased suicidality. Conclusion: Based on the proposed data, there is no evidence that rTMS increases the risk for suicide during the course of the treatment. Conversely, rTMS tends to reduce suicidal ideation. Our findings call for further rTMS controlled studies using large sample sizes and specific suicidality assessment measures to obtain more conclusive results.

A 6-Year Follow-up Study of Vagus Nerve Stimulation Effect on Quality of Life in Treatment-Resistant Depression: A Pilot Study

OBJECTIVES

Treatment-resistant depression (TRD) carries a major burden on those affected by this disease and significantly impacts their quality of life (QOL). Vagus nerve stimulation (VNS) has showed promising results on symptoms, but its impact on QOL remains underresearched. This study aims to evaluate the long-term effects of VNS on both QOL and clinical symptoms for TRD patients, through a naturalistic 6-year follow-up.

METHOD

Outpatients with confirmed TRD were enrolled to receive VNS. None of the patients enrolled left the study or was lost at follow-up. Patients were evaluated at 1, 3, 6, 12, 24, 36, 48, 60, and 72 months for a total of 10 assessments using the 36 item Short Form questionnaire, Hamilton Rating Scale for Depression and Hamilton Anxiety Rating Scale.

RESULTS

Ten patients were enrolled with a mean age of 50 years. This study shows a clinically and statistically significant improvement of the mental QOL (P = 0.012), physical QOL (P < 0.002), depressive symptoms (P < 0.001), and anxiety symptoms (P < 0.001).

CONCLUSIONS

This long-term naturalistic study is the first to demonstrate that the therapeutic effect of VNS on TRD goes beyond clinical symptoms to improve the daily QOL of those affected.

Emerging Roles of Sonic Hedgehog in Adult Neurological Diseases: Neurogenesis and Beyond

Sonic hedgehog (Shh), a member of the hedgehog (Hh) family, was originally recognized as a morphogen possessing critical characters for neural development during embryogenesis. Recently, however, Shh has emerged as an important modulator in adult neural tissues through different mechanisms such as neurogenesis, anti-oxidation, anti-inflammation, and autophagy. Therefore, Shh may potentially have clinical application in neurodegenerative diseases and brain injuries. In this article, we present some examples, including ours, to show different aspects of Shh signaling and how Shh agonists or mimetics are used to alter the neuronal fates in various disease models, both in vitro and in vivo. Other potential mechanisms that are discussed include alteration of mitochondrial function and anti-aging effect; both are critical for age-related neurodegenerative diseases. A thorough understanding of the protective mechanisms elicited by Shh may provide a rationale to design innovative therapeutic regimens for various neurodegenerative diseases.

Mending the heart and mind during times of loss: A review of interventions to improve emotional well-being during spousal bereavement

Spousal loss is one of life's greatest stressors. Bereaved spouses are at risk for aberrant cognitive and affective processing. Recent work in psychoneuroimmunology and cognitive neuroscience reveals physiological biomarkers and neural mechanisms underlying acute distress and grief during bereavement that may represent targets for future interventions. We review evidence from existing pharmacological and psychotherapeutic treatment approaches for normal bereavement, complicated grief, and bereavement-related depression. We propose promising future directions, namely the development and empirical validation of novel, personalised cognitive and neurostimulatory interventions to promote adaptive emotion regulation and reduce depressive symptoms following spousal loss. Future work may substantiate which interventions to improve emotional and physical health will be best matched to the needs of a particular surviving spouse.

Factors Associated With Global Variability in Electroconvulsive Therapy Utilization

OBJECTIVES

The aims of this study were to investigate the social and economic factors that contribute to global variability in electroconvulsive therapy (ECT) utilization and to contrast these to the factors associated with antidepressant medication rates.

METHODS

Rates of ECT and antidepressant utilization across nations and data on health, social, and economic indices were obtained from multiple international organizations including the World Health Organization and the Organization for Economic Co-operation and Development, as well as from the published literature. To assess whether relationships exist between selected indices and each of the outcome measures, a correlational analysis was conducted using Pearson correlation coefficients. Those that were significant at a level of P < 0.05 in the correlation analysis were selected for entry into the multivariate analyses. Selected predictor variables were entered into a stepwise multiple regression models for ECT and antidepressant utilization rates separately.

RESULTS

A stepwise multiple regression analysis indicated that government expenditure on mental health was the only significant contributor to the model, explaining 34.2% of global variation in ECT use worldwide. Human Development Index was the only variable found to be significantly correlated with global antidepressant utilization, accounting for 71% of the variation in global antidepressant utilization.

CONCLUSIONS

These findings suggest that across the globe ECT but not antidepressant medication utilization is associated with the degree to which a nation financially invests in mental health care for its citizens.

Epilepsy as a Network Disorder (1): What can we learn from other network disorders such as autistic spectrum disorder and mood disorders?

Epilepsy is a neurologic condition which often occurs with other neurologic and psychiatric disorders. The relation between epilepsy and these conditions is complex. Some population-based studies have identified a bidirectional relation, whereby not only patients with epilepsy are at increased risk of suffering from some of these neurologic and psychiatric disorders (migraine, stroke, dementia, autism, depression, anxiety disorders, Attention deficit hyperactivity disorder (ADHD), and psychosis), but also patients with these conditions are at increased risk of suffering from epilepsy. The existence of common pathogenic mechanisms has been postulated as a potential explanation of this phenomenon. To reassess the relationships between neurological and psychiatric conditions in general, and specifically autism, depression, Alzheimer's disease, schizophrenia, and epilepsy, a recent meeting brought together basic researchers and clinician scientists entitled "Epilepsy as a Network Disorder." This was the fourth in a series of conferences, the "Fourth International Halifax Conference and Retreat". This manuscript summarizes the proceedings on potential relations between Epilepsy on the one hand and autism and depression on the other. A companion manuscript provides a summary of the proceedings about the relation between epilepsy and Alzheimer's disease and schizophrenia, closed by the role of translational research in clarifying these relationships. The review of the topics in these two manuscripts will provide a better understanding of the mechanisms operant in some of the common neurologic and psychiatric comorbidities of epilepsy.

Challenging Treatment-Resistant Major Depressive Disorder: A Roadmap for Improved Therapeutics

Major depressive disorder (MDD) is associated with a significant burden and costs to the society. As remission of depressive symptoms is achieved in only one-third of the MDD patients after the first antidepressant trial, unsuccessful treatments contribute largely to the observed suffering and social costs of MDD. The present article provides a summary of the therapeutic strategies that have been tested for treatment-resistant depression (TRD). A computerized search on MedLine/PubMed database from 1975 to September 2014 was performed, using the keywords “treatment-resistant depression”, “major depressive disorder”, “adjunctive”, “refractory” and “augmentation”. From the 581 articles retrieved, two authors selected 79 papers. A manual searching further considered relevant articles of the reference lists. The evidence found supports adding or switching to another antidepressant from a different class is an effective strategy in more severe MDD after failure to an initial antidepressant trial. Also, in subjects resistant to two or more classes of antidepressants, some augmentation strategies and antidepressant combinations should be considered, although the overall response and remission rates are relatively low, except for fast acting glutamatergic modulators. The wide range of available treatments for TRD reflects the complexity of MDD, which does not underlie diverse key features of the disorder. Larger and well-designed studies applying dimensional approaches to measure efficacy and effectiveness are warranted.

Electrical stimulation of the vmPFC serves as a remote control to affect VTA activity and improve depressive-like behavior

Despite progress in elucidating mechanisms of depression, the efficacy of different treatments remains inadequate. Recent small-scale clinical studies suggested anti-depressant treatment using deep brain stimulation (DBS) of the ventral capsule/ventral striatum or subgenual cingulate cortex (SCC), yet controlled, multi-center trials were unsuccessful. We recently suggested the ventral tegmental area (VTA) as an important intersection for treating depression. We also found that stimulation of the VTA of a genetic rat model of depression (Flinders Sensitive Line (FSL) rats) with a programmed pattern designed to mimic the burst firing of normal rats decreases depressive-like behavior. Herein, we examined the possibility of reaching the VTA - located deep in the brain stem - through its direct connection to the ventro-medial prefrontal cortex (vmPFC), which parallels the human SCC. Thus, we compared treatment of FSLs with modified versions of DBS - either chronic-intermittent low-frequency electrical stimulation of the vmPFC, or patterned acute electrical stimulation (pAES), which integrates transcranial magnetic stimulation properties, namely, bursts of pulse trains and low frequency stimulation, applied to the VTA. We found that stimulation of the vmPFC (20Hz, 15min/day, 10days) improved depressive-like behavior and VTA local field potential (LFP) activity of FSLs, yet it had only a partial long-term effect on behavior. In particular, vmPFC stimulation decreased theta band activity, which correlated with the improvement in depressive-like behavior of all treated FSLs at day 1, and in ~50% of treated FSLs at day 28 post treatment. pAES of the VTA (10Hz, 20min) caused significant, long-term improvement of depressive-like behavior of FSLs, concurrently with normalizing intra-VTA LFP activity, and increasing VTA LFP synchronicity and hippocampal BDNF mRNA levels. Thus, although low-frequency electrical stimulation of the PFC alters VTA activity, leading to attenuation of depressive-like manifestations, a specific stimulation pattern affecting VTA cell programming is important for long-term efficacy.

PBA regulates neurogenesis and cognition dysfunction after repeated electroconvulsive shock in a rat model

Electroconvulsive therapy (ECT) was widely used to treat the refractory depression. But ECT led to the cognitive deficits plaguing the depression patients. The underlying mechanisms of the cognitive deficits remain elusive. Repeated electroconvulsive shock (rECS) was used to simulate ECT and explore the mechanisms of ECT during the animal studies. Previous studies showed rECS could lead to neurogenesis and cognitive impairment. But it was well known that neurogenesis could improve the cognition. So these suggested that the mechanism of the cognitive deficit after rECS was very complex. In present study, we explored the probable mechanisms of the cognitive deficit after rECS from neurogenesis aspect. We found the cognitive deficit was reversible and neurogenesis could bring a long-term beneficial effect on cognition. Astrogliosis and NR1 down-regulation probably participated in the reversible cognitive deficits after rECS. Phenylbutyric acid (PBA), generally as an agent to investigate the roles of histone acetylation, could prevent the reversible cognitive dysfunction, but PBA could diminish the long-term effect of enhanced cognition by rECS. These suggested that ECT could possibly bring the long-term beneficial cognitive effect by regulating neurogenesis.

Update on Neuromodulation for Treatment-Resistant Depression

About 30% of patients suffering from a major depressive disorder do not respond sufficiently to established pharmacological, psychotherapeutic, or somatic treatments. Advances in technology and emerging knowledge about the dysfunctional brain circuits underlying depression have led to the development of different neuromodulation techniques. The aim of the present review is to give an update on noninvasive techniques, such as electroconvulsive therapy (ECT), magnetic seizure therapy (MST), transcranial magnetic stimulation (TMS), and invasive techniques requiring brain surgery, such as vagus nerve stimulation (VNS) and deep brain stimulation (DBS). First, the clinical relevance for therapy-resistant depression, including the current level of evidence, are presented. Neuroethics is concerned with the ethical, legal and social policy implications of neuroscience. A second focus of the review is the application of fundamental ethical principles, such as patient autonomy, patient well-being and justice to neuromodulation therapies. Due to reduced availability and lacking long-term efficacy data, most patients with treatment-resistant depression face a trial-and-error approach to therapeutics. This contravenes the ethical criteria of patient autonomy and justice. In order to raise the level of evidence, financial support of long-term studies, including large samples and randomized control trials, are necessary.

Multimodal approaches to define network oscillations in depression

The renaissance in the use of encephalography-based research methods to probe the pathophysiology of neuropsychiatric disorders is well afoot and continues to advance. Building on the platform of neuroimaging evidence on brain circuit models, magnetoencephalography, scalp electroencephalography, and even invasive electroencephalography are now being used to characterize brain network dysfunctions that underlie major depressive disorder using brain oscillation measurements and associated treatment responses. Such multiple encephalography modalities provide avenues to study pathologic network dynamics with high temporal resolution and over long time courses, opportunities to complement neuroimaging methods and findings, and new approaches to identify quantitative biomarkers that indicate critical targets for brain therapy. Such goals have been facilitated by the ongoing testing of novel invasive neuromodulation therapies, notably, deep brain stimulation, where clinically relevant treatment effects can be monitored at multiple brain sites in a time-locked causal manner. We review key brain rhythms identified in major depressive disorder as foundation for development of putative biomarkers for objectively evaluating neuromodulation success and for guiding deep brain stimulation or other target-based neuromodulation strategies for treatment-resistant depression patients.

Concordance Between BeamF3 and MRI-neuronavigated Target Sites for Repetitive Transcranial Magnetic Stimulation of the Left Dorsolateral Prefrontal Cortex

Background

The dorsolateral prefrontal cortex (DLPFC) is a common target for repetitive transcranial magnetic stimulation (rTMS) in major depression, but the conventional “5 cm rule” misses DLPFC in > 1/3 cases. Another heuristic, BeamF3, locates the F3 EEG site from scalp measurements. MRI-guided neuronavigation is more onerous, but can target a specific DLPFC stereotaxic coordinate directly. The concordance between these two approaches has not previously been assessed.

Objective

To quantify the discrepancy in scalp site between BeamF3 versus MRI-guided neuronavigation for left DLPFC.

Methods

Using 100 pre-treatment MRIs from subjects undergoing left DLPFC-rTMS, we localized the scalp site at minimum Euclidean distance from a target MNI coordinate (X − 38 Y + 44 Z + 26) derived from our previous work. We performed nasion-inion, tragus–tragus, and head-circumference measurements on the same subjects’ MRIs, and applied the BeamF3 heuristic. We then compared the distance between BeamF3 and MRI-guided scalp sites.

Results

BeamF3-to-MRI-guided discrepancies were <0.65 cm in 50% of subjects, <0.99 cm in 75% of subjects, and <1.36 cm in 95% of subjects. The angle from midline to the scalp site did not differ significantly using MRI-guided versus BeamF3 methods. However, the length of the radial arc from vertex to target site was slightly but significantly longer (mean 0.35 cm) with MRI-guidance versus BeamF3.

Conclusions

The BeamF3 heuristic may provide a reasonable approximation to MRI-guided neuronavigation for locating left DLPFC in a majority of subjects. A minor optimization of the heuristic may yield additional concordance.

Intracranial applications of magnetic resonance-guided focused ultrasound

The ability to focus acoustic energy through the intact skull on to targets millimeters in size represents an important milestone in the development of neurotherapeutics. Magnetic resonance-guided focused ultrasound (MRgFUS) is a novel, noninvasive method, which--under real-time imaging and thermographic guidance--can be used to generate focal intracranial thermal ablative lesions and disrupt the blood-brain barrier. An established treatment for bone metastases, uterine fibroids, and breast lesions, MRgFUS has now been proposed as an alternative to open neurosurgical procedures for a wide variety of indications. Studies investigating intracranial MRgFUS range from small animal preclinical experiments to large, late-phase randomized trials that span the clinical spectrum from movement disorders, to vascular, oncologic, and psychiatric applications. We review the principles of MRgFUS and its use for brain-based disorders, and outline future directions for this promising technology.