Repetitive Transcranial Magnetic Stimulation for Obsessive-Compulsive Disorder: A Meta-analysis of Randomized, Sham-Controlled Trials

Repetitive transcranial magnetic stimulation for major depression and obsessive-compulsive disorders in Singapore

Introduction

Repetitive transcranial magnetic stimulation (rTMS) is used for treatment-resistant major depressive disorder (MDD) and obsessive-compulsive disorder (OCD), but there are few studies on patient outcomes in Southeast Asia. In this study, we describe the clinical profile and outcome of patients with MDD and OCD treated with rTMS in Singapore.

Method

A naturalistic retrospective study of 71 patients (inpatient and outpatient) who received rTMS treatment between June 2018 and April 2023 was conducted. The depressive and obsessive outcome rating scales used were clinician-rated Montgomery-Åsberg Depression Rating Scale (MADRS), Yale-Brown Obsessive Compulsive Scale (Y-BOCS), Clinical Global Impressions-Severity (CGI-S) and self-rated Depression Anxiety and Stress Scale-21 (DASS-21).

Results

Clinician-rated and self-rated mood and general condition improved significantly. MADRS mean score improved from 28.1 (standard deviation [SD] 7.3) to 20.7 (SD 10.1) (P<0.0001) (20.8% response rate/17% remission rate). CGI-S mean 4.6 (SD 0.8) improved to 3.3 (SD 1.2) (P<0.0001). DASS-21 total mean improved from 67.3 (SD 24.6) to 49.6 (SD 28.0) (P<0.0001). Y-BOCS mean score displayed a trend towards improvement from 30.1 (SD 7.5) to 27.2 (SD 6.9) (P=0.799). However, 44.4% of patients with OCD responded with a minimal 20% reduction in baseline Y-BOCS. Moreover, the subgroup of 35.8% of patients with less than 30 rTMS sessions had contributed disproportionately to nonresponse (85.7%). Patients who received rTMS treatment (>30 sessions) had a trend of larger improvement of MADRS score when compared to patients with (≤30 sessions) (9.4 [SD 9.7] versus 3.8 [SD 12.3] [P=0.078]).

Conclusion

Response and remission rates for MDD and OCD suggest patients have a good response to rTMS treatment. Dosing longer rTMS sessions after an acute course helps to maximise effectiveness. Further research to determine predictors of outcome and characterise clinical features of late responders to target treatment more effectively is recommended.

The promise and challenges of transcranial magnetic stimulation and deep brain stimulation as therapeutic options for obsessive-compulsive disorder

INTRODUCTION

Obsessive compulsive disorder (OCD) represents a complex and often difficult to treat disorder. Pharmacological and psychotherapeutic interventions are often associated with sub-optimal outcomes, and 40-60% of patients are resistant to first line therapies and thus left with few treatment options. OCD is underpinned by aberrant neurocircuitry within cortical, striatal, and thalamic brain networks. Considering the neurocircuitry impairments that underlie OCD symptomology, neurostimulation therapies provide an opportunity to modulate psychopathology in a personalized manner. Also, by probing pathological neural networks, enhanced understanding of disease states can be obtained.

AREAS COVERED

This perspective discusses the clinical efficacy of TMS and DBS therapies, treatment access options, and considerations and challenges in managing patients. Recent scientific progress is discussed, with a focus on neurocircuitry and biopsychosocial aspects. Translational recommendations and suggestions for future research are provided.

EXPERT OPINION

There is robust evidence to support TMS and DBS as an efficacious therapy for treatment resistant OCD patients supported by an excellent safety profile and favorable health economic data. Despite a great need for alternative therapies for chronic and severe OCD patients, resistance toward neurostimulation therapies from regulatory bodies and the psychiatric community remains. The authors contend for greater access to TMS and DBS for treatment resistant OCD patients at specialized sites with appropriate clinical resources, particularly considering adjunct and follow-up care. Also, connectome targeting has shown robust predictive ability of symptom improvements and holds potential in advancing personalized neurostimulation therapies.

A Controlled Clinical Study of Accelerated High-Dose Theta Burst Stimulation in Patients with Obsessive-Compulsive Disorder

Background

Obsessive-compulsive disorder (OCD) is frequently treated using a combination of counseling, drugs, and, more recently various transcranial stimulation protocols, but all require several weeks to months for clinically significant improvement, so there is a need for treatments with faster onset. This study investigated whether an accelerated high-dose theta burst stimulation (ahTBS) protocol significantly improves the efficacy of OCD compared to traditional 1-Hz repetitive transcranial magnetic stimulation (rTMS) in the routine clinical setting.

Method

Forty-five patients with OCD were randomized into two groups and treated with ahTBS or 1-Hz rTMS for 5 days. Patients were assessed at baseline at the end of treatment using the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS).

Results

After 5 days of treatment, there was a significant decrease in Y-BOCS scores in both groups (p < 0.001), and the difference between the two groups was not statistically significant (group × time interaction, F = 1.90, p=0.18). There was also no statistically significant difference in other secondary outcome indicators, including depression, anxiety symptoms, and response rate. However, the ahTBS group had a greater trend in response rate. Neuropsychological testing showed no negative cognitive side effects of either treatment.

Conclusion

Accelerated high-dose TBS is as safe and has comparable short-term efficacy to traditional 1-Hz rTMS for the clinical treatment of OCD. Further research is needed to explore optimal ahTBS parameters, validate the utility of this treatment modality, and identify factors predictive of rapid clinical response to guide clinical decision-making. This trial is registered with NCT05221632.

Efficacy of Repetitive Transcranial Magnetic Stimulation on Comorbid Anxiety and Depression Symptoms in Obsessive-Compulsive Disorder: A Meta-Analysis of Randomized Sham-Controlled Trials

OBJECTIVE

To systematically evaluate the efficacy of repetitive transcranial magnetic stimulation (rTMS) in reducing comorbid anxiety and depressive symptoms in patients with obsessive-compulsive disorder (OCD).

METHODS

Three electronic databases were searched for randomized, sham-controlled clinical trials evaluating rTMS for the treatment of OCD. Hedge's g was calculated as the effect size for anxiety/depression symptom severity (primary outcome) and OCD severity (secondary outcome). Subgroup analyses and meta-regression analyses were carried out to evaluate the most promising target and whether a reduction in OCD severity moderates the change in anxiety or depression scores.

RESULTS

Twenty studies (n = 688) were included in the meta-analysis. rTMS had small-medium effect size on OCD (Hedge's g = 0.43; 95% confidence interval [CI]: [0.20, 0.65]; P < 0.001), anxiety (Hedge's g = 0.3; 95% CI: [0.11, 0.48]; P = 0.001) and depression (Hedge's g = 0.24; 95% CI: [0.07, 0.40]; P = 0.003) symptoms. Subgroup analysis showed that protocols targeting dorsolateral prefrontal cortex (DLPFC) were effective for 3 outcome measures. The change in anxiety, but not depression severity, was moderated by a change in OCD symptom scores. However, the findings are uncertain as a majority of the studies had some concerns or a high risk of bias.

CONCLUSIONS

Active rTMS protocol targeting DLPFC is effective in reducing the comorbid anxiety/depression symptoms along with OCD severity. The antidepressant effect is not moderated by the anti-obsessive effect of rTMS.

Neuromodulation of OCD: A review of invasive and non-invasive methods

Early research into neural correlates of obsessive compulsive disorder (OCD) has focused on individual components, several network-based models have emerged from more recent data on dysfunction within brain networks, including the the lateral orbitofrontal cortex (lOFC)-ventromedial caudate, limbic, salience, and default mode networks. Moreover, the interplay between multiple brain networks has been increasingly recognized. As the understanding of the neural circuitry underlying the pathophysiology of OCD continues to evolve, so will too our ability to specifically target these networks using invasive and noninvasive methods. This review discusses the rationale for and theory behind neuromodulation in the treatment of OCD.

Efficacy of Non-Invasive Brain Stimulation for Refractory Obsessive-Compulsive Disorder: A Meta-Analysis of Randomized Controlled Trials

Obsessive-compulsive disorder (OCD) is a neuropsychiatric disorder, with 30−40% of OCD patients being unresponsive to adequate trials of anti-OCD drugs and cognitive behavior therapy. The aim of this paper is to investigate the efficacy of non-invasive brain stimulation (NIBS) on treating refractory OCD. With PubMed, Embase, PsycInfo, and Cochrane Library used on 15 February 2022, 24 randomized controlled trials involving 663 patients were included. According to this analysis, NIBS including repetitive transcranial magnetic stimulation (rTMS), theta-burst stimulation (TBS), and transcranial direct current stimulation (tDCS), had a moderate effect on the reduction of Yale-Brown Obsessive Compulsive Scale (Y-BOCS) scores (SMD = 0.54, 95% CI: 0.26−0.81; p < 0.01). In the subgroup analysis, rTMS seemed to produce a better therapeutic effect (SMD = 0.73, 95% CI: 0.38−1.08; p < 0.01). Moreover, excitatory (SMD = 1.13, 95% CI: 0.24−2.01; p = 0.01) and inhibitory (SMD = 0.81, 95% CI: 0.26−1.36; p < 0.01) stimulation of the dorsolateral prefrontal cortex (DLPFC) both alleviated OCD symptoms. In the secondary outcome of clinical response rates, NIBS treatment led to an increase in response rates (RR = 2.26, 95% CI: 1.57−3.25; p < 0.01).

Brain stimulation and other biological non-pharmacological interventions in mental disorders: An umbrella review

BACKGROUND

The degree of efficacy, safety, quality, and certainty of meta-analytic evidence of biological non-pharmacological treatments in mental disorders is unclear.

METHODS

We conducted an umbrella review (PubMed/Cochrane Library/PsycINFO-04-Jul-2021, PROSPERO/CRD42020158827) for meta-analyses of randomized controlled trials (RCTs) on deep brain stimulation (DBS), transcranial magnetic stimulation (TMS), transcranial direct current stimulation (tDCS), electro-convulsive therapy (ECT), and others. Co-primary outcomes were standardized mean differences (SMD) of disease-specific symptoms, and acceptability (for all-cause discontinuation). Evidence was assessed with AMSTAR/AMSTAR-Content/GRADE.

RESULTS

We selected 102 meta-analyses. Effective interventions compared to sham were in depressive disorders: ECT (SMD=0.91/GRADE=moderate), TMS (SMD=0.51/GRADE=moderate), tDCS (SMD=0.46/GRADE=low), DBS (SMD=0.42/GRADE=very low), light therapy (SMD=0.41/GRADE=low); schizophrenia: ECT (SMD=0.88/GRADE=moderate), tDCS (SMD=0.45/GRADE=very low), TMS (prefrontal theta-burst, SMD=0.58/GRADE=low; left-temporoparietal, SMD=0.42/GRADE=low); substance use disorder: TMS (high frequency-dorsolateral-prefrontal-deep (SMD=1.16/GRADE=moderate), high frequency-left dorsolateral-prefrontal (SMD=0.77/GRADE=very low); OCD: DBS (SMD=0.89/GRADE=moderate), TMS (SMD=0.64/GRADE=very low); PTSD: TMS (SMD=0.46/GRADE=moderate); generalized anxiety disorder: TMS (SMD=0.68/GRADE=low); ADHD: tDCS (SMD=0.23/GRADE=moderate); autism: tDCS (SMD=0.97/GRADE=very low). No significant differences for acceptability emerged. Median AMSTAR/AMSTAR-Content was 8/2 (suggesting high-quality meta-analyses/low-quality RCTs), GRADE low.

DISCUSSION

Despite limited certainty, biological non-pharmacological interventions are effective and safe for numerous mental conditions. Results inform future research, and guidelines.

FUNDING

None.

Efficacy of neurostimulation across mental disorders: systematic review and meta-analysis of 208 randomized controlled trials

Non-invasive brain stimulation (NIBS), including transcranial magnetic stimulation (TMS), and transcranial direct current stimulation (tDCS), is a potentially effective treatment strategy for a number of mental conditions. However, no quantitative evidence synthesis of randomized controlled trials (RCTs) of TMS or tDCS using the same criteria including several mental conditions is available. Based on 208 RCTs identified in a systematic review, we conducted a series of random effects meta-analyses to assess the efficacy of NIBS, compared to sham, for core symptoms and cognitive functioning within a broad range of mental conditions. Outcomes included changes in core symptom severity and cognitive functioning from pre- to post-treatment. We found significant positive effects for several outcomes without significant heterogeneity including TMS for symptoms of generalized anxiety disorder (SMD = -1.8 (95% CI: -2.6 to -1), and tDCS for symptoms of substance use disorder (-0.73, -1.00 to -0.46). There was also significant effects for TMS in obsessive-compulsive disorder (-0.66, -0.91 to -0.41) and unipolar depression symptoms (-0.60, -0.78 to -0.42) but with significant heterogeneity. However, subgroup analyses based on stimulation site and number of treatment sessions revealed evidence of positive effects, without significant heterogeneity, for specific TMS stimulation protocols. For neurocognitive outcomes, there was only significant evidence, without significant heterogeneity, for tDCS for improving attention (-0.3, -0.55 to -0.05) and working memory (-0.38, -0.74 to -0.03) in individuals with schizophrenia. We concluded that TMS and tDCS can benefit individuals with a variety of mental conditions, significantly improving clinical dimensions, including cognitive deficits in schizophrenia which are poorly responsive to pharmacotherapy.