Efficacy of repetitive transcranial magnetic stimulation in the prevention of relapse of depression: study protocol for a randomized controlled trial

Systematic review of preservation TMS that includes continuation, maintenance, relapse-prevention, and rescue TMS

BACKGROUND

A dearth of evidence-based information exists to guide the delivery of transcranial magnetic stimulation (TMS) after a successful acute course of treatment for Major Depressive Disorder.

METHODS

To provide guidance for clinicians, existing literature focused on "preservation TMS" was systematically reviewed and synthesized. Preservation TMS was defined as TMS used to sustain a clinical response after a successful acute course of treatment and included reports using the terms maintenance, continuation, relapse prevention, or rescue TMS. The review protocol was registered on Open Science Framework and reported following PRISMA guidelines. Data were abstracted by two authors and discrepancies were resolved by a third author. Primary outcome measures focused on clinical efficacy. The evaluated studies were graded using the Levels of Evidence criteria published by the Oxford Centre for Evidence-Based Medicine.

RESULTS

The search included 536 abstracts and 16 additional papers, from which 63 full articles were screened. Data were abstracted from 30 qualifying sources (N=1,494) including 4 randomized controlled trials (one sham controlled), 14 open trials, and 12 case series. Overall, the quality of existing literature was low regarding efficacy but provided clear support for effectiveness and safety across a range of preservation TMS protocols based on mostly uncontrolled studies.

CONCLUSIONS

Existing literature suggests that preservation TMS protocols significantly vary and are mostly supported by open trials and case series. Due to a lack of effective alternatives, preservation TMS will likely be required for certain patients who respond to acute TMS therapy. More studies of preservation TMS are critically needed.

Repetitive transcranial magnetic stimulation on the modulation of cortical and spinal cord excitability in individuals with spinal cord injury

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) has been applied for modulating cortical excitability and treating spasticity in neurological lesions. However, it is unclear which rTMS frequency is most effective in modulating cortical and spinal excitability in incomplete spinal cord injury (SCI).

OBJECTIVE

To evaluate electrophysiological and clinical repercussions of rTMS compared to sham stimulation when applied to the primary motor cortex (M1) in individuals with incomplete SCI.

METHODS

A total of 11 subjects (35±12 years) underwent three experimental sessions of rTMS (10 Hz, 1 Hz and sham stimulation) in a randomized order at 90%intensity of the resting motor threshold and interspersed by a seven-day interval between sessions. The following outcome measures were evaluated: M1 and spinal cord excitability and spasticity in the moments before (baseline), immediately after (T0), 30 (T30) and 60 (T60) minutes after rTMS. M1 excitability was obtained through the motor evoked potential (MEP); spinal cord excitability by the Hoffman reflex (H-reflex) and homosynaptic depression (HD); and spasticity by the modified Ashworth scale (MAS).

RESULTS

A significant increase in cortical excitability was observed in subjects submitted to 10 Hz rTMS at the T0 moment when compared to sham stimulation (p = 0.008); this increase was also significant at T0 (p = 0.009), T30 (p = 0.005) and T60 (p = 0.005) moments when compared to the baseline condition. No significant differences were observed after the 10 Hz rTMS on spinal excitability or on spasticity. No inter-group differences were detected, or in the time after application of 1 Hz rTMS, or after sham stimulation for any of the assessed outcomes.

CONCLUSIONS

High-frequency rTMS applied to M1 was able to promote increased cortical excitability in individuals with incomplete SCI for at least 60 minutes; however, it did not modify spinal excitability or spasticity.

Repetitive Transcranial Magnetic Stimulation Combined with Antidepressants for the First Episode of Major Depressive Disorder

OBJECTIVES

The aims of this study were to systematically review the efficacy, acceptability, and tolerability of repetitive transcranial magnetic stimulation (rTMS) combined with antidepressants in the treatment of the first major depressive disorder (MDD) episode.

MATERIALS AND METHODS

The primary efficacious outcome was the pooled mean-endpoint scores of the Hamilton Depression Rating Scale (HAMD). Rates of response, remission rate, overall discontinuation and discontinuation due to adverse events were also evaluated. Search in the Scopus, PubMed, CINAHL, and Cochrane Controlled Trials Register databases for interesting outcomes was carried out in March 2018.

RESULTS

A total of 108 randomized patients of two randomized controlled trials were included in this study. The pooled mean- endpoint scores of the HAMD in one, two, and four weeks for rTMS plus antidepressants (citalopram or paroxetine) were greater than that of sham plus the antidepressants. The pooled rates of overall discontinuation and discontinuation rates due to adverse events were not different between the two groups.

CONCLUSION

According to a piece of limited evidence, the high-frequency repetitive transcranial magnetic stimulation (HF-rTMS) could accelerate the antidepressant effect of SSRIs in young patients with a first-episode major depressive disorder. However, the acceptability and tolerability of HF-rTMS in the treatment of such patients are no better than an antidepressant alone. However, further well-defined and large sample-size studies of HF-rTMS combined with an antidepressant in MDD should be carried out to warrant these results.

Potential predictors of depressive relapse following repetitive Transcranial Magnetic Stimulation: A systematic review

BACKGROUND

Repetitive Transcranial Magnetic Stimulation (rTMS) is widely approved treatment for major depressive disorder (MDD). However, around 50% of individuals who recover from depression following rTMS interventions experience a relapse of depressive symptomatology by 12 months. The short-term durability of the rTMS treatment effect has been systematically investigated. However, variables relating to the long-term durability of the antidepressant effect produced by rTMS are less understood. Therefore, the current review systematically assessed the research on variables relating to relapse following rTMS.

METHOD

This systematic review was performed according to PRISMA guidelines. A comprehensive electronic literature search for terms related to relapse following rTMS treatment for MDD was performed on studies published before the end of October 2018.

RESULTS

A total of 18 studies assessing relapse related variables were identified. While there is some indication that comorbid anxiety, acute response, and residual symptomatology may hold predictive potential for depressive relapse following rTMS treatment, findings were not sufficient to draw reliable conclusions.

DISCUSSION

Identified studies assessed three main categories of variables including demographic information, clinical characteristics and rating scale scores, and rTMS treatment specific factors. Only a small number of studies were available, and considerable inconsistency exists between studies, only limited conclusions were able to be drawn.

CONCLUSION

More studies assessing a wider range of predictor variables such as cognitive or neuroimaging markers are needed.

Effects of rTMS on Hippocampal Endocannabinoids and Depressive-like Behaviors in Adolescent Rats

Depression is a common mental disorder in adolescents, with a prevalence rate of 5.6%. Current anti-depressive options for adolescents are limited: psychological intervention and conventional antidepressants have low efficacy, a delayed onset of action and increased possibility of suicidal risk. Repetitive transcranial magnetic stimulation (rTMS) as an effective and noninvasive physical therapy for adult depression has been investigated in recent years. However, whether it also produces similar effects on juvenile depression and the underlying mechanism are not clearly understood. In this study, chronic unpredictable mild stress (CMS) was applied to 3-week-old male Sprague Dawley rats for 21 days. Then rTMS was performed for seven consecutive days, and the anti-depressive effects were evaluated by behavioral tests including the sucrose preference test (SPT), the forced swimming test (FST), and the novelty suppressed feeding test (NSF). Expression of hippocampal cannabinoid type I receptor (CB1R), 2-arachidonoylglycerol (2-AG) and relative synthetase and degradative enzymes-diacylglycerol lipase (DAGL) and monoacylglycerol lipase (MAGL) were also investigated. The behavioral parameters were also observed after the administration of the selective CB1 receptor antagonist AM251. The results showed that CMS induced a significant decrease in sucrose preference, a significant increase of immobility time in the FST, and an increased latency to feed in the NSF. In addition, reduced hippocampal CB1 receptor, 2-AG level and increased MAGL protein expression level were also observed in CMS rats. Meanwhile, rTMS treatment upregulated 2-AG level in the hippocampus and ameliorated depressive-like behaviors. The anti-depressive effect of rTMS was attenuated by AM251, a specific CB1R antagonist that was administered 30 min before the onset of rTMS by either intraperitoneal administration or hippocampal microinjection. These results indicate that rTMS can be used as an antidepressive therapy for juvenile depression at least partly mediated by increasing hippocampal 2-AG and CB1 receptor expression levels.

Clustered repetitive transcranial magnetic stimulation for the prevention of depressive relapse/recurrence: a randomized controlled trial

Repetitive transcranial magnetic stimulation (rTMS) may have the potential to prevent depressive relapse. This assessor-blinded, randomized controlled study was designed to evaluate the efficacy and safety of rTMS as a mono- and combination therapy in the prevention of depressive relapse/recurrence. A total of 281 depressed patients who had achieved stable full or partial remission on a 6-month antidepressant (ADP) run-in treatment were randomly assigned to an rTMS (n = 91), ADP (n = 108), or combined (rTMS + ADP, n = 82) treatment group for 12 months. Monthly clustered rTMS was conducted in 5-10 sessions over a 3-5-day period. Maintenance outcomes were assessed using time to relapse/recurrence and relapse/recurrence rate. Overall, 71.2% (200/281) of the participants completed the treatment per the protocol. rTMS + ADP and rTMS significantly reduced the risk of relapse/recurrence compared with ADP (P = 0.000), with hazard ratios of 0.297 and 0.466, respectively. Both rTMS-containing regimens produced significantly lower relapse/recurrence rates than ADP (15.9% and 24.2% vs. 44.4%, P < 0.001). In the relapsed/recurrent subgroup, first-episode depressed, rTMS-treated patients had a markedly lower relapse/recurrence rate than ADP-treated patients. Five patients on the ADP-containing regimens, but none on rTMS alone, developed acute mania. The rTMS-containing regimens had considerably more certain side effects than did the ADP group. We concluded that TMS, whether as a mono- or additional therapy, is superior to antidepressants in preventing depressive relapse/recurrence, particularly in first-episode depressed patients. The treatment does not increase the risk of manic switch, but may increase the risk of certain side effects.

Long Non-Coding RNA: Potential Diagnostic and Therapeutic Biomarker for Major Depressive Disorder

Background

The criteria for diagnosing depression are based on behavioral observation and self-reporting of symptoms by the patients or guardians without any biological validation of the disease. This study aimed to identify long non-coding RNAs (lncRNAs) in peripheral blood mononuclear cells (PBMCs) as robust and predictive biomarkers for diagnosis and therapy response in major depressive disorder (MDD).

Material/Methods

We used human lncRNA 3.0 microarray profiling (which covers 30,586 human lncRNAs), using PBMCs from five MDD patients and five controls. Differentially expressed lncRNAs in the PBMCs of MDD patients were identified, of which 10 candidate lncRNAs were selected for real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis in a larger cohort of 138 MDD patients and 63 healthy controls. Then among the 138 MDD patients who received standard antidepressant treatment, 30 were randomly selected for lncRNAs expression retesting and symptomatology assessments after three-weeks and six-weeks of antidepressant treatment.

Results

Six lncRNAs (TCONS_00019174, ENST00000566208, NONHSAG045500, ENST00000517573, NONHSAT034045, and NONHSAT142707) were significantly downregulated in MDD patients compared to control patients, and the area under the receiver operator curve (ROC) of these six lncRNAs cases, combined, was 0.719 (95% confidence interval (CI): 0.617–0.821). There was no difference in the expression of these six lncRNAs based on gender (p>0.05) or age (p>0.05).

Conclusions

These results suggest that the combined expression of six lncRNAs in PBMCs may serve as a potential biomarker for diagnosis and therapy response of MDD in the clinical setting.

hsa_circRNA_103636: potential novel diagnostic and therapeutic biomarker in Major depressive disorder

Aim: This study aimed to determine whether circular RNA (circRNA) molecules in peripheral blood mononuclear cells (PBMCs) could be used as novel non-invasive biomarkers for major depressive disorder (MDD). Materials & methods: Differentially expressed circRNAs were screened using an Arraystar Human CircRNA Array (which includes 13,617 human circRNAs) and qRT-PCR. Thirty MDD patients were randomly selected to retest the circRNA levels after 4-week and 8-week antidepressant regimens. Results: Four differentially expressed circRNAs were identified between MDD patients and controls, and only down-regulated hsa_circRNA_103636 was significantly altered after the 8-week treatment in MDD patients. Conclusion: These results suggest that altered expression of hsa_circRNA_103636 in PBMCs is a potential novel biomarker for the diagnosis and treatment of MDD.