Short-term efficacy of repetitive transcranial magnetic stimulation (rTMS) in depression- reanalysis of data from meta-analyses up to 2010

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Exploratory study on neurochemical effects of low-intensity pulsed ultrasound in brains of mice

There is now a relatively large body of evidence suggesting a relationship between dysfunction of myelin and oligodendrocytes and the etiology of several neuropsychiatric disorders, including depression and schizophrenia, and also suggesting that ultrasound methods may alleviate some of the symptoms of depression. We have applied low-intensity pulsed ultrasound (LIPUS) to the brains of mice treated with the demyelinating drug cuprizone, a drug that has been used as the basis for a rodent model relevant to a number of psychiatric and neurologic disorders including depression, schizophrenia, and multiple sclerosis. Prior to conducting the studies in mice, preliminary studies were carried out on the effects of LIPUS in vitro in neuron-like SH-SY5Y cells and primary glial cells. In subsequent studies in mice, female C57BL/6 mice were restrained in plastic tubes for 20 min daily with the ultrasound transducer near the end of the tube directly above the mouse's head. LIPUS was used at an intensity of 25 mW/cm² once daily for 22 days in control mice and in mice undergoing daily repetitive restraint stress (RRS). Behavioral or neurochemical studies were done on the mice or the brain tissue obtained from them. The studies in vitro indicated that LIPUS stimulation at an intensity of 15 mW/cm² delivered for 5 min daily for 3 days in an enclosed sterile cell culture plate in an incubator increased the viability of SH-SY5Y and primary glial cells. In the studies in mice, LIPUS elevated levels of doublecortin, a marker for neurogenesis, in the cortex compared to levels in the RRS mice and caused a trend in elevation of brain levels of brain-derived neurotrophic factor in the hippocampus relative to control levels. LIPUS also increased sucrose preference (a measure of the attenuation of anhedonia, a common symptom of several psychiatric disorders) in the RRS model in mice. The ability of LIPUS administered daily to rescue damaged myelin and oligodendrocytes was studied in mice treated chronically with cuprizone for 35 days. LIPUS increased cortex and corpus callosum levels of myelin basic protein, a protein marker for mature oligodendrocytes, and neural/glial antigen 2, a protein marker for oligodendrocyte precursor cells, relative to levels in the cuprizone + sham animals. These results of this exploratory study suggest that future comprehensive time-related studies with LIPUS on brain chemistry and behavior related to neuropsychiatric disorders are warranted. Exploratory Study on Neurochemical Effects of Low Intensity Pulsed Ultrasound in Brains of Mice. Upper part of figure: LIPUS device and in-vitro cell experimental set-up. The center image is the LIPUS generating box; the image in the upper left shows the cell experiment set-up; the image in the upper right shows a zoomed-in sketch for the cell experiment; the image in the lower left shows the set-up of repetitive restraint stress (RRS) with a mouse; the image in the lower middle shows the set-up of LIPUS treatment of a mouse; the image in the lower right shows a zoomed-in sketch for the LIPUS treatment of a mouse.

Treatment for Major Depressive Disorder by Repetitive Transcranial Magnetic Stimulation in Different Parameters: A Randomized Double-Blinded Controlled Trial

Background: Repetitive transcranial magnetic stimulation (rTMS) has been proven to be safe and effective in treating major depressive disorder (MDD). However, the treatment parameters of rTMS are still divergent and need to be optimized further. The aim of this study was to compare the efficacy of rTMS in treating MDD with different parameters of stimulating frequency and location, and course of treatment. Methods: A total of 221 patients with MDD were recruited in the randomized, double-blind, controlled trial. All eligible patients were randomly assigned into four treatment groups: (1) 10 Hz in left dorsolateral pre-frontal cortex (DLPFC) (n = 55), (2) 5 Hz in left DLPFC (n = 53), (3) 10 Hz in bilateral DLPFC (n = 57), and (4) 5 Hz in bilateral DLPFC (n = 56). The patients received treatment for 6 weeks and an additional 6-week optional treatment. The efficacies were evaluated by Hamilton Depression Rating Scale-24 items (HDRS) and Clinical Global Impressions Scale (CGI). The trial is registered at the Chinese Clinical Trial Registry as ChiCTR-TRC-12002248. Results: The ANOVAs of HDRS scores up to 6 weeks and 12 weeks with repeated measure of time showed a significant effect of duration without statistical difference among four treatment groups and no significance when time was interacted with inter-group as well. The response rates up until the 5th week were significantly different with the previous week. Conclusions: It concludes that there were no statistical differences in the efficacy of rTMS between unilateral left and bilateral DLPFC, and between 5 and 10 Hz for treating MDD.

Appraising the effectiveness of electrical and magnetic brain stimulation techniques in acute major depressive episodes: an umbrella review of meta-analyses of randomized controlled trials

Electrical and magnetic brain stimulation techniques present distinct mechanisms and efficacy in the acute treatment of depression. This was an umbrella review of meta-analyses of randomized controlled trials of brain stimulation techniques for managing acute major depressive episodes. A systematic review was performed in the PubMed/MEDLINE databases from inception until March 2020. We included the English language meta-analysis with the most randomized controlled trials on the effects of any brain stimulation technique vs. control in adults with an acute depressive episode. Continuous and dichotomous outcomes were assessed. A Measurement Tool to Assess Systematic Reviews-2 was applied and the credibility of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation framework. Seven meta-analyses were included (5,615 patients), providing evidence for different modalities of brain stimulation techniques. Three meta-analyses were evaluated as having high methodological quality, three as moderate, and one as low. The highest quality of evidence was found for high frequency-repetitive transcranial magnetic stimulation (rTMS), transcranial direct current stimulation, and bilateral rTMS. There is strong clinical research evidence to guide future clinical use of some techniques. Our results confirm the heterogeneity of the effects across these techniques, indicating that different mechanisms of action lead to different efficacy profiles.

Pregenual or subgenual anterior cingulate cortex as potential effective region for brain stimulation of depression

BACKGROUND

The dorsolateral prefrontal cortex (DLPFC) is the standard stimulation target for the repetitive transcranial magnetic stimulation (rTMS) treatment of major depression disorder (MDD). A retrospective study by Fox and colleagues found that a more negative resting-state functional magnetic resonance imaging (RS-fMRI) functional connectivity (FC) between left DLPFC and the subgenual anterior cingulate cortex (sgACC) in a large group of healthy participants is associated with a better curative effects of rTMS in MDD, suggesting that the sgACC may be an effective region. However, a recent meta-analysis on RS-fMRI studies found that the pregenual ACC (pgACC), rather than the sgACC, of MDD patients showed increased local activity.

METHODS

We used the stimulation coordinates in the left DLPFC analyzed by Fox et al. to perform RS-fMRI FC between the stimulation targets obtained from previous rTMS MDD studies and the potential effective regions (sgACC and pgACC, respectively) on the RS-fMRI data from 88 heathy participants.

RESULTS

(a) Both the pgACC and the sgACC were negatively connected to the left DLPFC; (b) both FCs of sgACC-DLPFC and pgACC-DLPFC were more negative in responders than in nonresponders; and (c) the associations between DLPFC-sgACC functional connectivity and clinical efficacy were clustered around the midline sgACC.

CONCLUSIONS

Both the pgACC and the sgACC may be potential effective regions for rTMS on the left DLPFC for treatment of MDD. However, individualized ACC-DLPFC FC-based rTMS on depression should be performed in the future to test the pgACC or the sgACC as effective regions.

Theta-Burst Stimulation for Auditory-Verbal Hallucination in Very-Late-Onset Schizophrenia-Like Psychosis-A Functional Magnetic Resonance Imaging Case Study

BACKGROUND

Treating very-late-onset (>60 years) schizophrenia-like psychosis (VLOSLP) is challenging. Age-related factors in elderly individuals (e.g., metabolism, medication side effects, drug-interaction, somatic morbidity) may adversely affect treatment. Novel therapeutic approaches are needed to ensure the favorable therapeutic outcome in geriatric patients. Previously, theta-burst stimulation (TBS), a novel form of repetitive transcranial magnetic stimulation, was reported being beneficial in the treatment for auditory-verbal hallucination (AVH) in young and middle-aged schizophrenia (SZ) patients.

CASE PRESENTATION

Here we present a case of a male patient aged 73. His first psychotic episode manifested with paranoid delusions, auditory-verbal and tactile hallucinations at the age of 66, and first remitted following a second-generation antipsychotics (SGA). Years later, after a relapse the AVH did not respond to previously effective olanzapine, whereas its augmentation with an inhibitory TBS over the left temporal lobe led to a stable remission. During his second relapse, TBS was again capable of facilitating therapeutic action of SGA in the same patient. Extending to our clinical observation, a series of functional MRI scans employing a tonal activation paradigm depicted altered auditory processing during AVH as well as brain activation change during remission.

CONCLUSIONS

The current case might indicate to favorable effects of combining conventional medicament therapy and non-invasive brain stimulation techniques for elderly patients. Also, we speculate that despite obviously distinct etiologies, the present functional imaging and clinical observation may also demonstrate a possible common pathophysiological pathway underlying AVH in VLOSLP and SZ.

Antidepressant outcomes of high-frequency repetitive transcranial magnetic stimulation (rTMS) with F8-coil and deep transcranial magnetic stimulation (DTMS) with H1-coil in major depression: a systematic review and meta-analysis

BACKGROUND

The current study aims to systematically assess and compare the antidepressant outcomes of repetitive transcranial magnetic stimulation (rTMS) with the figure-of-eight (F8)-coil and deep transcranial magnetic stimulation (DTMS) with the H1-coil in studies matched on stimulation frequency in unipolar major depressive disorder (MDD).

METHODS

Electronic search of Medline and PsycInfo identified 19 studies with stimulation frequency of 18-20 Hz using F8-coil (k = 8 randomised sham-controlled trials, RCTs, k = 3 open-label; n = 168 patients) or H1-coil (k = 1 RCT, k = 7 open-label; n = 200). Depression severity (the primary outcome) and response/remission rates (the secondary outcomes) were assessed at session 10.

RESULTS

Effects pooled with random-effects meta-analysis showed a large reduction in depression severity, 29% response, and 15% remission rates after 10 sessions of active stimulation with either coil relative to baseline. Reduction in depression severity was greater in studies with younger patients using either coil. The comparison between coils showed a larger reduction in depression severity in H1-coil vs. F8-coil studies (independent of the study design or the concurrent pharmacotherapy) and a trend towards higher remission rates in F8-coil vs. H1-coils studies. These effects are based on a low volume of studies, are not controlled for placebo, and may not be clinically-relevant. The stimulation protocols differed systematically because stimulation was more focal but less intense (80-110% of the resting motor threshold, MT) in the F8-coil studies and less focal but more intense (120% MT) in the H1-coil studies. Two seizures occurred in the H1-coil studies relative to none in the F8-coil studies.

CONCLUSION

When matched on frequency, the higher-intensity and less focal stimulation with the H1-coil reduces depression more than the lower-intensity and more focal stimulation with the F8-coil. Head-to-head trials should compare the antidepressant outcomes of F8-coil and H1-coil to identify the most optimal stimulation protocols for acute and longer-lasting efficacy.

Sleep-wake, cognitive and clinical correlates of treatment outcome with repetitive transcranial magnetic stimulation for young adults with depression

The utility of key phenotypes of depression in predicting response to repetitive transcranial magnetic stimulation (rTMS), namely sleep-wake behaviour, cognition and illness chronicity, has been understudied and not been extended to young samples. This study aimed to determine whether sleep-wake disturbance, cognition or depression chronicity are associated with rTMS outcome in young depressed adults. Sixteen depressed young adults diagnosed with mood disorders (aged 18-29 years) completed this open-label study. Neuronavigationally targeted high-frequency rTMS was administered at 110% of motor threshold on the left dorsolateral prefrontal cortex for 20 sessions over 4 weeks. Clinical, sleep-wake and cognitive assessments were undertaken pre- and post-treatment. Repeated-measures and correlational analyses determined pre- and post-treatment changes and predictors of treatment outcome. rTMS significantly reduced depression and anxiety. Better cognitive flexibility, verbal learning, later age of onset and greater number of depressive episodes were associated with better treatment outcome. There were no other significant/trend-level associations. rTMS had no effect on sleep-wake or cognitive measures. We provide the first evidence for the utility of cognitive flexibility and verbal learning in predicting rTMS outcome in depressed young adults. This research provides preliminary support for rTMS as an early intervention for depression and supports the need for sham-controlled trials.

Durability of antidepressant response to repetitive transcranial magnetic stimulation: Systematic review and meta-analysis

BACKGROUND

The therapeutic options for treatment-resistant depression (TRD) encompass a range of neuromodulatory techniques, including repetitive transcranial magnetic stimulation (rTMS). While rTMS is safe and has documented short-term efficacy, durability of antidepressant effects is poorly established.

OBJECTIVE

Assess existing evidence regarding durability of rTMS-induced antidepressant response.

METHODS

We performed a systematic review of studies reporting antidepressant outcome measures collected three or more months after the end of an induction course of rTMS for depression. Among responders to the induction course, we used a meta-analytic approach to assess response rates at 3 (m3), 6 (m6) or 12 (m12) months after induction, and studied predictors of responder rates using meta-regression.

RESULTS

Nineteen studies published between 2002 and 2018 were included. Eighteen were eligible for analysis at m3 (732 patients) and m6 (695 patients) and 9 at m12 (247 patients). Among initial responders, 66.5% sustained response at m3 (95% CI = 57.1-74.8%, I² = 27.6%), 52.9% at m6 (95% CI = 40.3-65%, I² = 0%), and 46.3% at m12 (95% CI = 32.6-60.7%, I² = 0%), in the absence of any major bias. Random-effects meta-regressions further demonstrated that a higher proportion of women, as well as receipt of maintenance treatment, predicted higher responder rates at specific time-points.

CONCLUSIONS

rTMS is a durable treatment for depression, with sustained responder rates of 50% up to 1 year after a successful induction course of treatment. Maintenance treatment may enhance the durability of the antidepressant effects of rTMS, and should be considered in clinical practice, as well as systematically explored in future clinical trials.

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

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

An Update of a Meta-Analysis on the Clinical Outcomes of Deep Transcranial Magnetic Stimulation (DTMS) in Major Depressive Disorder (MDD)

Abstract. Deep transcranial magnetic stimulation (DTMS) is a noninvasive therapy for treatment-resistant major depressive disorder (MDD). The current study aimed to update a previous meta-analysis by investigating the acute and longer-term clinical outcomes of DTMS and their possible predictors (patient characteristics and stimulation parameters) in unipolar MDD. A systematic literature search identified 11 studies with 282 treatment-resistant, unipolar MDD patients. The clinical outcomes (depression severity, response and remission rates) were evaluated using random-effects meta-analyses. High frequency and intensity DTMS protocol with H1-coil had significant acute antidepressant outcomes and improved some cognitive functions after 20 daily sessions in unipolar MDD. Response rates tended to increase with lower severity of illness. Antidepressant effects were prolonged if maintenance DTMS was used after daily stimulation phases. DTMS consistently improves various symptom domains (antidepressant, cognitive) in treatment-resistant unipolar MDD.

Functional connectivity of the left DLPFC to striatum predicts treatment response of depression to TMS

BACKGROUND

Repetitive transcranial magnetic stimulation (TMS) is a non-invasive, safe, and efficacious treatment for depression. TMS has been shown to normalize abnormal functional connectivity of cortico-cortical circuits in depression and baseline functional connectivity of these circuits predicts treatment response. Less is known about the relationship between functional connectivity of frontostriatal circuits and treatment response.

OBJECTIVE/HYPOTHESIS

We investigated whether baseline functional connectivity of distinct frontostriatal circuits predicted response to TMS.

METHODS

Resting-state fMRI (rsfMRI) was acquired in 27 currently depressed subjects with treatment resistant depression and 27 healthy controls. Depressed subjects were treated with 5 weeks of daily TMS over the left dorsolateral prefrontal cortex (DLPFC). The functional connectivity between limbic, executive, rostral motor, and caudal motor regions of frontal cortex and their corresponding striatal targets were determined at baseline using an existing atlas based on diffusion tensor imaging. TMS treatment response was measured by percent reduction in the 24-item Hamilton Depression Rating Scale (HAMD24). In an exploratory analysis, correlations were determined between baseline functional connectivity and TMS treatment response.

RESULTS

Seven cortical clusters belonging to the executive and rostral motor frontostriatal projections had reduced functional connectivity in depression compared to healthy controls. No frontostriatal projections showed increased functional connectivity in depression (voxel-wise p < 0.01, family-wise α < 0.01). Only baseline functional connectivity between the left DLPFC and the striatum predicted TMS response. Higher baseline functional connectivity correlated with greater reductions in HAMD₂₄ (Pearson's R = 0.58, p = 0.002).

CONCLUSION(S)

In an exploratory analysis, higher functional connectivity between the left DLPFC and striatum predicted better treatment response. Our findings suggest that the antidepressant mechanism of action of TMS may require connectivity from cortex proximal to the stimulation site to the striatum.

Efficacy of theta burst stimulation (TBS) for major depression: An exploratory meta-analysis of randomized and sham-controlled trials

Theta burst stimulation (TBS) has been proposed as a novel treatment for major depression (MD). However, randomized and sham-controlled trials (RCTs) published to date have yielded heterogeneous clinical results and we have thus carried out the present systematic review and exploratory meta-analysis of RCTs to evaluate this issue. We searched the literature for RCTs on TBS for MD from January 2001 through September 2016 using MEDLINE, EMBASE, PsycINFO, and CENTRAL. We then performed a random-effects meta-analysis with the main outcome measures including pre-post score changes in the Hamilton Depression Rating Scale (HAM-D) as well as rates of response, remission and dropout. Data were obtained from 5 RCTs, totalling 221 subjects with MD. The pooled Hedges' g for pre-post change in HAM-D scores was 1.0 (p = 0.003), indicating a significant and large-sized difference in outcome favouring active TBS. Furthermore, active TBS was associated with significantly higher response rates when compared to sham TBS (35.6% vs. 17.5%, respectively; p = 0.005), although the groups did not differ in terms of rates of remission (18.6% vs. 10.7%, respectively; p = 0.1) and dropout (4.2% vs. 7.8%, respectively; p = 0.5). Finally, subgroup analyses indicated that bilateral TBS and unilateral intermittent TBS seem to be the most promising protocols. In conclusion, although TBS is a promising novel therapeutic intervention for MD, future studies should identify more clinically-relevant stimulation parameters as well as neurobiological predictors of treatment outcome, and include larger sample sizes, active comparators and longer follow-up periods.

Repetitive Transcranial Magnetic Stimulation for Depression Due to Cerebrovascular Disease: A Systematic Review

OBJECTIVE

This study aims to perform a systematic review evaluating the effectiveness of repetitive transcranial magnetic stimulation (rTMS) in improving depression resulting from cerebrovascular disease including vascular depression (VD) and poststroke depression (PSD).

METHODS

A literature search of multiple scientific databases was conducted for English studies published from January 1980 to June 2016. Studies were included if the sample consisted of 50% or more adult humans with VD or PSD and had 3 or more subjects, the intervention applied was rTMS, and depression was assessed pre- and post intervention using a formal outcome measure. Randomized controlled trials (RCTs) were assessed for methodological quality using the Physiotherapy Evidence Database (PEDro) tool. A level of evidence was assigned to each study according to the modified Sackett Scale.

RESULTS

Five studies met the inclusion criteria including 3 RCTs (level 1b; PEDro range: 6-8) and 2 uncontrolled pre-post studies (level 4). There were 186 participants with either PSD (n = 40) or VD (n = 146); the majority of the participants were female (52.7%) and had a mean age ranging from 51.9 to 67.9 years. There were no adverse effects reported by any of the studies. Using clinically accepted criteria for the response rate, all studies reported a benefit from rTMS for the treatment of depression. Three studies also demonstrated a benefit on remission rates as well.

CONCLUSIONS

rTMS was reported to be beneficial in treating depression among individuals with cerebrovascular disease over the short term. However, heterogeneous populations and variability in study design and protocol, as well as a limited number of studies to review, challenge the ability to form conclusions as to the effectiveness of rTMS.

Seizure Induced by Deep Transcranial Magnetic Stimulation in an Adolescent with Depression

OBJECTIVE

Deep transcranial magnetic stimulation (TMS) with an H-1 coil was recently approved by the U.S. Food and Drug Administration (U.S. FDA) for treatment-resistant depression (TRD) in adults. Studies assessing the safety and effectiveness of deep TMS in adolescent TRD are lacking. The purpose of this brief report is to provide a case history of an adolescent enrolled in an investigational deep TMS protocol.

METHODS

A case history is described of the first participant of a sham-controlled clinical trial who had a seizure in the course of deep TMS with parameter settings extrapolated from the adult studies that led to US FDA approval (H-1 coil, 120% target stimulation intensity, 18 Hz, 55 trains of 2-second duration, total 1980 pulses).

RESULTS

The participant was a 17-year-old unmedicated female, with no significant medical history and no history of seizures or of drug or alcohol use. Brain magnetic resonance imaging showed no structural abnormalities. She initially received sham, which was well tolerated. During active treatment sessions, titration began at 85% of motor threshold (MT) and increased by 5% per day. Her weekly MT measurements were stable. On her first day of 120% MT (8th active treatment), during the 48th train, the participant had a generalized, tonic-clonic seizure that lasted 90 seconds and resolved spontaneously. She had an emergency medicine evaluation and was discharged home without anticonvulsant medications. There were no further seizures reported at a 6-month follow-up.

CONCLUSIONS

We report a deep TMS-induced generalized tonic-clonic seizure in an adolescent with TRD participating in a clinical trial. Given the demonstrated benefits of deep TMS for adult TRD, research investigating its use in adolescents with TRD is an important area. However, in light of this experience, additional precautions for adolescents should be considered. We propose that further dose-finding investigations are needed to refine adolescent-specific parameters that may be safe and effective for treating adolescents with TRD with deep TMS.

Deep transcranial magnetic stimulation (DTMS) in the treatment of major depression: An exploratory systematic review and meta-analysis

BACKGROUND

Deep transcranial magnetic stimulation (DTMS) is a relatively new, non-invasive method of stimulating larger and, presumably, deeper brain regions. The current study investigated if DTMS delivered with H-coils has acute antidepressant effects in major depression using a systematic literature review and a quantitative meta-analysis.

METHODS

Seventeen studies on 'DTMS or H-coil' and 'depression' were identified on Medline, PsycInfo, and Google Scholar (until November 2014). Data from nine open-label studies were meta-analysed using a random-effects model with inverse-variance weights. The outcome measures were the standardised paired mean difference (Cohen's d) in depression scores on Hamilton Depression Rating Scale (HDRS), response, remission, and dropout rates after acute DTMS treatment compared to baseline.

RESULTS

There was a large antidepressant effect after 20 acute, high-frequency DTMS sessions compared to baseline according to HDRS change scores (overall mean weighted d=2.04, 95% confidence interval: 1.53-2.55; nine studies; 150 patients). Overall weighted response, remission, and dropout rates were 60%, 29%, and 18% respectively. HDRS change scores and response rates tended to be higher in four studies with 68 patients on concurrent antidepressants compared to two studies with 26 patients who received DTMS as a monotherapy.

LIMITATIONS

These results are based on data from a low number of open-label studies.

CONCLUSION

High-frequency DTMS appears to have acute antidepressant effects after 20 sessions in mostly unipolar and treatment-resistant patients. Concurrent treatment with antidepressants might enhance the efficacy of DTMS.

Neuromodulation therapies for geriatric depression

Depression is frequent in old age and its prognosis is poorer than in younger populations. The use of pharmacological treatments in geriatric depression is limited by specific pharmacodynamic age-related factors that can diminish tolerability and increase the risk of drug interactions. The possibility of modulating cerebral activity using brain stimulation techniques could result in treating geriatric depression more effectively while reducing systemic side effects and medication interactions. This may subsequently improve treatment adherence and overall prognosis in the older patient. Among clinically available neuromodulatory techniques, electroconvulsive therapy (ECT) remains the gold standard for the treatment of severe depression in the elderly. Studies have proven that ECT is more effective and has a faster onset of action than antidepressants in the treatment of severe, unipolar, geriatric depression and that older age is a predictor of rapid ECT response and remission. The application of novel and more tolerable forms of ECT for geriatric depression is currently being examined. Preliminary results suggest that right unilateral ultrabrief ECT (RUL-UB ECT) is a promising intervention, with similar efficacy to brief-pulse ECT and fewer adverse cognitive effects. Overall findings in repetitive transcranial magnetic stimulation (rTMS) suggest that it is a safe intervention in geriatric depression. Higher rTMS stimulation intensity and more treatments may need to be given in the elderly to achieve optimal results. There is no specific data on vagus nerve stimulation in the elderly. Transcranial direct current stimulation, magnetic seizure therapy and deep brain stimulation are currently experimental, and more data from geriatric samples is needed.

Durability of the antidepressant effect of the high-frequency repetitive transcranial magnetic stimulation (rTMS) In the absence of maintenance treatment in major depression: a systematic review and meta-analysis of 16 double-blind, randomized, sham-controlled trials

BACKGROUND

The aim of the current meta-analysis was to investigate predictors of the durability of the antidepressant effect of high-frequency (>1 Hz) repetitive transcranial magnetic stimulation (rTMS) of the left dorsolateral prefrontal cortex in the absence of active maintenance treatment.

METHODS

Following a systematic literature search of Medline and PsycInfo, N = 16 double-blind, parallel-design, randomized-controlled trials (RCTs) with high-frequency rTMS and inactive sham were included in the current meta-analysis. The effect size (Cohen's d) was the standardized mean difference in depression scores between sham and rTMS groups (baseline -follow-up). Meta-analysis was conducted according to a random-effects model with inverse-variance weights.

RESULTS

Most RCTs reported only short follow-up phases of 2 weeks (range of 1-16 weeks). The antidepressant effect was observed during follow-up (in the absence of maintenance treatment) compared to baseline (overall mean weighted d = -.48, 95% confidence interval: -.70, -.25, P < .001, N = 16 RCTs with 495 patients). Such an antidepressant effect during follow-up was higher in RCTs with patients who were less severely ill, unipolar, nonpsychotic, treatment-resistant, and on antidepressants (either started with rTMS or continued at stable doses during acute treatment phases). The effect sizes were lower in RCTs with longer (8-16 weeks) compared to shorter (1-4 weeks) follow-up periods. The risk of publication bias was low.

CONCLUSIONS

High-frequency rTMS has only a small antidepressant effect during follow-up after short acute treatment (5-15 sessions) in the absence of active maintenance treatment. This effect depends on illness severity, decreases over time, and appears to be enhanced by antidepressants.