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.

Association between daily dose and efficacy of rTMS over the left dorsolateral prefrontal cortex in depression: A meta-analysis

Repetitive transcranial magnetic stimulation (rTMS) is a well-established, safe, and effective brain stimulation technique for depression; however, uniform parameters have not been used in clinical practice. The aim of this study was to identify the parameters that affect rTMS effectiveness and ascertain the range in which that parameter has optimal efficacy. A meta-analysis of sham-controlled trials using rTMS delivered over the left dorsolateral prefrontal cortex (DLPFC) in depression was conducted. In the meta-regression and subgroup analyses, all rTMS stimulation parameters were extracted and their association with efficacy was investigated. Of the 17,800 references, 52 sham-controlled trials were included. Compared to sham controls, our results demonstrated a significant improvement in depressive symptoms at the end of treatment. According to the results of meta-regression, the number of pulses and sessions per day correlated with rTMS efficacy; however, the positioning method, stimulation intensity, frequency, number of treatment days, and total pulses did not. Furthermore, subgroup analysis revealed that the efficacy was correspondingly better in the group with higher daily pulses. In clinical practice, increasing the number of daily pulses and sessions may improve the effectiveness of rTMS.

The Association Between Sample and Treatment Characteristics and the Efficacy of Repetitive Transcranial Magnetic Stimulation in Depression: A Meta-analysis and Meta-regression of Sham-controlled Trials

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) is a form of non-invasive neuromodulation that is increasingly used to treat major depressive disorder (MDD). However, treatment with rTMS could be optimized by identifying optimal treatment parameters or characteristics of patients that are most likely to benefit. This meta-analysis and meta-regression aims to identify sample and treatment characteristics that are associated with change in depressive symptom level, treatment response and remission.

METHODS

The databases PubMed, Embase, Web of Science and Cochrane library were searched for randomized controlled trials (RCTs) reporting on the therapeutic efficacy of high-frequent, low-frequent, or bilateral rTMS for MDD compared to sham. Study and sample characteristics as well as rTMS parameters and outcome variables were extracted. Effect sizes were calculated for change in depression score and risk ratios for response and remission.

RESULTS

Sixty-five RCTs with a total of 2982 subjects were included in this meta-analysis. Active rTMS resulted in a larger depressive symptom reduction than sham protocol (Hedges' g = -0.791 95% CI -0.977; -0.605). Risk ratios for response and remission were 2.378 (95% CI 1.882; 3.005) and 2.450 (95% CI 1.779; 3.375), respectively. We found no significant association between sample and treatment parameters and rTMS efficacy.

CONCLUSIONS

rTMS is an efficacious treatment for MDD. No associations between sample or treatment characteristics and efficacy were found, for which we caution that publication bias, heterogeneity and lack of consistency in the definition of remission might bias these latter null findings. Our results are clinically relevant and support the use of rTMS as a non-invasive and effective treatment option for depression.

Comparative Efficacy and Acceptability of 3 Repetitive Transcranial Magnetic Stimulation Devices for Depression: A Meta-Analysis of Randomized, Sham-Controlled Trials

INTRODUCTION

Repetitive transcranial magnetic stimulation (rTMS) has been employed worldwide for therapy-resistant depression. The Food and Drug Administration has approved a number of therapeutic devices for treating major depressive disorder; however, no studies have examined the differences in efficacy and acceptability among commercially available stimulation devices. The aim of our study was to compare the efficacy and acceptability of 3 stimulation devices (NeuroStar, MagPro, and Magstim) for depressive disorders.

METHODS

Our study included 31 randomized sham-controlled trials of high-frequency rTMS included in the network meta-analysis by Brunoni. We calculated the risk ratio and 95% confidence intervals, comparing each device with sham for the endpoints of response rate, remission rate, and all-cause discontinuation. We then analyzed the differences among the devices in effect size for those endpoints.

RESULTS

After determining the effect sizes for the endpoints, we found no statistically significant subgroup differences in the response rates, all-cause discontinuation, or remission rates among the devices (p = 0.12, p = 0.84, and p = 0.07, respectively).

CONCLUSION

Our results suggest similar efficacy and acceptability for the 3 stimulation devices. Future studies need to perform head-to-head comparisons of the efficacy and acceptability of the stimulation devices for treating depression using the same stimulation protocols.

Magnitude of the Placebo Response Across Treatment Modalities Used for Treatment-Resistant Depression in Adults: A Systematic Review and Meta-analysis

IMPORTANCE

The placebo effect in depression clinical trials is a substantial factor associated with failure to establish efficacy of novel and repurposed treatments. However, the magnitude of the placebo effect and whether it differs across treatment modalities in treatment-resistant depression (TRD) is unclear.

OBJECTIVE

To examine the magnitude of the placebo effect in patients with TRD across different treatment modalities and its possible moderators.

DATA SOURCES

Searches were conducted on MEDLINE, Web of Science, and PsychInfo from inception to June 21, 2021.

STUDY SELECTION

Randomized clinical trials (RCTs) were included if they recruited patients with TRD and randomized them to a placebo or sham arm and a pharmacotherapy, brain stimulation, or psychotherapy arm.

DATA EXTRACTION AND SYNTHESIS

Independent reviewers used standard forms for data extraction and quality assessment. Random-effects analyses and standard pairwise meta-analyses were performed.

MAIN OUTCOMES AND MEASURES

The primary outcome was the Hedges g value for the reported depression scales. Secondary outcomes included moderators assessed via meta-regression and response and remission rates. Heterogeneity was assessed with the I2 test, and publication bias was evaluated using the Egger test and a funnel plot. Cochrane Risk of Bias Tool was used to estimate risks.

RESULTS

Fifty RCTs were included involving various types of placebo or sham interventions with a total of 3228 participants (mean [SD] age, 45.8 [6.0] years; 1769 [54.8%] female). The pooled placebo effect size for all modalities was large (g = 1.05; 95% CI, 0.91-1.1); the placebo effect size in RCTs of specific treatment modalities did not significantly differ. Similarly, response and remission rates associated with placebo were comparable across modalities. Heterogeneity was large. Three variables were associated with a larger placebo effect size: open-label prospective treatment before double-blind placebo randomization (β = 0.35; 95% CI, 0.11 to 0.59; P = .004), later year of publication (β = 0.03; 95% CI, 0.003 to 0.05; P = .03), and industry-sponsored trials (β = 0.34; 95% CI, 0.09 to 0.58; P = .007). The number of failed interventions was associated with the probability a smaller placebo effect size (β = -0.12; 95% CI, -0.23 to -0.01, P = .03). The Egger test result was not significant for small studies' effects.

CONCLUSIONS AND RELEVANCE

This analysis may provide a benchmark for past and future clinical RCTs that recruit patients with TRD standardizing an expected placebo effect size.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

A randomized controlled trial of a standard 4-week protocol of repetitive transcranial magnetic stimulation in severe treatment resistant depression

BACKGROUND

Treatment options for major depressive disorder (MDD) in individuals who are depressed for at least 2 years and failed two or more different types of therapeutic intervention, remain scarce. Being less invasive than electroconvulsive therapy, repetitive transcranial magnetic stimulation (rTMS) might be an alternative treatment option.

RESEARCH QUESTION

Does high frequency rTMS applied over the left prefrontal cortex ameliorate depressive symptoms in patients with treatment resistant major depressive disorder and is the efficacy dependent on treatment resistance?

METHOD

We performed a randomized controlled trial investigating the effect of twenty sessions of real or sham-rTMS, during 4 consecutive weeks. Efficacy was blindly rated with the Hamilton depression rating scale (HDRS-17) at baseline and 1 week after end of treatment, and the Dutch method for quantification of treatment resistance in Depression (DM-TRD) was assessed at baseline.

RESULTS

An interim analysis showed no differences in antidepressant response between real and sham rTMS and we therefore discontinued the RCT after 31 patients. The mean difference of the HDRS score between baseline and post-treatment was 3.7 (± 4.0; change 16%), indicating a small but significant improvement across time (F(1,30)=25.4;p < 0.01). There were no differences however between the treatment arms (F(1.30) = 1.5;p = 0.23). We did find a negative correlation between the change in HDRS score and DM-TRD in the active rTMS group, but this correlation was not significantly different from the sham group.

CONCLUSION

"Standard" 4-week rTMS treatment is not effective in chronic, severe treatment-resistant depressed patients. While a replication of our data in this patient group may be ethically difficult, further research with less treatment resistant patients might help in positioning rTMS within the current stepped care approach to depression.

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.

A systematic review and meta-analysis on placebo response to repetitive transcranial magnetic stimulation for depression trials

BACKGROUND

Although several studies indicate that placebo response is large to antidepressant pharmacotherapy in major depressive disorder (MDD), no updated meta-analysis has quantified the magnitude of the placebo (sham) response to repetitive transcranial magnetic stimulation (rTMS) in MDD yet.

OBJECTIVE

To conduct a systematic review and meta-analysis on this issue in randomized controlled trials (RCTs) involving participants with MDD; and to explore potential moderators.

METHODOLOGY

PubMed/MEDLINE, Embase, PsycINFO, and Web of Science electronic databases were searched from inception up to March 15, 2017 for RCTs that investigated the efficacy of any rTMS modality compared to sham intervention in participants with acute depressive episodes. Cochrane Risk of Bias Tool was used to estimate risks. We estimated the placebo effect size (Hedges's g, random-effects model) response using placebo groups baseline and endpoint depressive symptom scores. Meta-regressions have been employed to explore potential moderators of response.

RESULTS

Sixty-one studies met eligibility criteria (N=1328; mean age, 47years; 57% females). Placebo response was large (g=0.8, 95% CI=0.65-0.95, p<0.01) regardless of the modality of intervention. Placebo response was directly associated with publication year and depression improvement of the active group, and inversely associated with higher levels of treatment-resistant depression. Other moderators, including gender, age, and stimulator type, were not associated with the outcome. Overall, 24.6%, 67.2%, and 8.2% of studies had an overall low, unclear, and high bias risk, respectively.

CONCLUSION

Placebo response in rTMS depression trials was large and associated with depression improvement of the active treatment group. Such result suggests that excluding placebo responders with a run-in phase may not confer advantage since response to 'active' rTMS may decrease as well. Moreover, placebo response may be a component of therapeutic response to rTMS in MDD. In addition, placebo response increase over time could indicate improvement in rTMS trial designs, including better sham rTMS methods.

Comparative efficacy and tolerability of pharmacological and somatic interventions in adult patients with treatment-resistant depression: a systematic review and network meta-analysis

OBJECTIVE

Major depressive disorder (MDD) affects about 10-15% of the general population in a lifetime. A considerable number of patients fail to achieve full symptom remission despite adequate treatment and are considered treatment resistant (TRD). The current study compared the relative efficacy and tolerability of pharmacological and somatic TRD interventions by means of a Bayesian network meta-analysis.

RESEARCH DESIGN AND METHODS

An electronic literature search of MEDLINE, MEDLINE In-Process, EMBASE, PsycInfo, EconLit and Cochrane Library databases for trials published between September 2003 and September 2014 was conducted. Key outcomes extracted were disease severity change from baseline, response and remission rates at various timepoints and discontinuation due to adverse events.

RESULTS

Of the 3876 abstracts identified, 31 publications/randomised controlled trials (RCTs) were included in the analysis; 19 RCTs investigating 13 pharmacological interventions and 12 RCTs investigating electroconvulsive therapy (ECT) and repetitive transcranial magnetic stimulation (rTMS). The evidence synthesis investigating efficacy outcomes of TRD treatments demonstrated superior efficacy for ketamine compared to pharmacological and somatic interventions at 2 weeks after treatment initiation. At 4, 6 and 8 weeks, quetiapine augmentation (800 mg/day) and risperidone augmentation were found to be the first and second best treatments, respectively. Networks were small for response rate and remission rate outcomes at most timepoints. The most tolerable treatment was lamotrigine augmentation showing a comparable profile to placebo/sham.

CONCLUSIONS

This analysis revealed scarcity of long-term data on sustained remission that would allow a comparative long-term efficacy assessment. Key limitations of the analysis can be considered the search timeframe and the use of mapping formula for the depression scores.

Repetitive transcranial magnetic stimulation as an augmentative strategy for treatment-resistant depression, a meta-analysis of randomized, double-blind and sham-controlled study

BACKGROUND

Dozens of randomized controlled trials (RCTs) and meta-analyses have demonstrated the efficacy of repetitive transcranial magnetic stimulation (rTMS) for major depressive disorder (MDD) treatment, but there has not been a meta-analysis report which evaluates the efficacy and tolerability of rTMS used as an augmentative strategy for antidepressants in treatment-resistant depression (TRD) treatment. We thus conducted this meta-analysis, aimed at clarifying whether rTMS enhances the efficacy of TRD.

METHODS

We searched MEDLINE and Cochrane Central Register of Controlled Trials for RCTs for studying the efficacy of rTMS versus (vs) sham condition when combined with antidepressants in TRD treatment, and screened the references of the previous meta-analysis about the rTMS for MDD treatment. Response rates and NNT were chose as the primary outcomes, and remission rates, change from baseline of HAMD scores, dropouts were used as secondary outcomes. For dichotomous data, an intention-to-treat analysis principle was applied; for continuous data, we calculated the standard mean difference between groups with a random-effect model. Sensitivity analysis was done to explore the source of heterogeneity and the factors which potentially impact the efficacy.

RESULTS

Seven RCTs were finally included in the meta-analysis. The total sample size was 279, with 171 in the rTMS group and 108 in the sham group. The pooled response and remission rate for the rTMS and sham group was 46.6% and 22.1%, respectively; the pooled odds ratio (OR) was 5.12 [95% confidence interval (CI) 2.11-12.45, z = 3.60, p = 0.0003, and the associated number needed to treat (NNT) was 3.4. rTMS group achieved a significant reduction of HAMD score than the sham group, the pooled SMD of change from baseline was 0.86 [95% confidence interval (CI) 0.57-1.15, z = 5.75, p < 0.00001]. Because of the small number of included RCTs, the preplanned sensitivity and subgroup analyses were finally abandoned. The dropouts in both groups were relatively low, indicating the high acceptability of rTMS.

CONCLUSIONS

For TRD patients, augmentative rTMS after the failure of medications significantly increases the effect of antidepressants, and rTMS was a safe strategy with relatively low adverse events and low dropout rate, suggesting that augmentative rTMS is an effective intervention for TRD.

A systematic review of the clinical relevance of repetitive transcranial magnetic stimulation

OBJECTIVE

Repetitive transcranial magnetic stimulation (rTMS) is an approved treatment for depression. The clinical relevance of its efficacy is unclear. The clinical relevance of findings in the rTMS literature was assessed by translating Hamilton Depression Rating Scale (HAMD) data into Clinical Global Impression-Improvement scale (CGI-I) scores.

METHOD

We performed electronic searches of MEDLINE, Embase, PsycINFO, PubMed and Cochrane Central Register of Controlled Trials for RCTs and non-RCT trials on rTMS using Hamilton Depression Rating Scale (HAMD). Articles were included if published in English before January 2014. We translated HAMD scores into nominal CGI-I scores for rTMS for depression and for treatment-resistant depression (TRD).

RESULTS

About 960 abstracts were retrieved. Sixty-three studies were included, yielding 130 study arms. For depression, the mean percentage change in HAMD scores in all sham-controlled rTMS treatment arms was 35.63 (SD 16.35) and for sham-rTMS 23.33 (SD 16.51). For TRD, active rTMS in sham-controlled studies showed a mean HAMD percentage reduction of 45.21 (SD 10.94) versus 25.04 (SD 17.55) for sham-rTMS. When aggregated scores were translated into notional CGI-I scores, for the treatment of depression, the notional CGI-I score difference between rTMS and sham-rTMS was 0.5 in favour of rTMS; for TRD, it was 0.75 in favour of rTMS. Differences between rTMS and sham-rTMS were bigger when all study arms were combined.

CONCLUSION

Whilst rTMS appears to be efficacious for both non-refractory and treatment-resistant depression, the clinical relevance of its efficacy is doubtful.