The role of low-frequency repetitive transcranial magnetic stimulation in major depression: A call to increase the evidence base

Trajectories of suicidal ideation during rTMS for treatment-resistant depression

BACKGROUND

rTMS is a safe and effective intervention for treatment-resistant depression (TRD). However, there is limited data on its specific impact on suicidal ideation (SI), and the trajectory of SI over the treatment course.

OBJECTIVE

This open-label clinical trial investigated SI outcomes and trajectories in patients with TRD receiving low-frequency rTMS (LFR) to the right dorsolateral prefrontal cortex (DLPFC; N = 55).

METHODS

A latent class mixed-effect model was used to identify response trajectories for SI as well as core mood symptoms. Logistic regression analyses investigated risk factors associated with identified trajectories.

RESULTS

For each symptom domain, we identified two distinct trajectories during LFR, one tracking improvement (SI: n = 35, 60 %; mood: n = 29, 53 %) and the other tracking no improvement (SI: n = 20, 40 %; mood: n = 26, 47 %). Male sex, higher baseline anxiety, and higher baseline SI were risk factors for no improvement of SI; while higher baseline anxiety and benzodiazepine use were risk factors for no improvement of mood. Mediation analyses showed that anxiety was a risk factor for no improvement of SI and mood independent of benzodiazepine treatment.

CONCLUSIONS

This is the first study to investigate trajectories of response to LFR to the right DLPFC. SI and mood improved with LFR in most patients but the severity of anxiety symptoms was a factor of poor prognosis for both. Nuanced characterization of SI response to rTMS may lead to critical insights for individualized targeting strategies.

A Review of Transcranial Magnetic Stimulation and Transcranial Direct Current Stimulation Combined with Medication and Psychotherapy for Depression

LEARNING OBJECTIVES

After participating in this CME activity, the psychiatrist should be better able to:• Compare and contrast therapies used in combination with transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) for treating MDD.

BACKGROUND

Noninvasive neuromodulation, such as transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS), has emerged as a major area for treating major depressive disorder (MDD). This review has two primary aims: (1) to review the current literature on combining TMS and tDCS with other therapies, such as psychotherapy and psychopharmacological interventions, and (2) to discuss the efficacy, feasibility, limitations, and future directions of these combined treatments for MDD.

METHOD

This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We searched three databases: PubMed, PsycInfo, and Cochrane Library. The last search date was December 5, 2023.

RESULTS

The initial search revealed 2,519 records. After screening and full-text review, 58 studies (7 TMS plus psychotherapy, 32 TMS plus medication, 7 tDCS plus psychotherapy, 12 tDCS plus medication) were included.

CONCLUSIONS

The current literature on tDCS and TMS paired with psychotherapy provides initial support for integrating mindfulness interventions with both TMS and tDCS. Adding TMS or tDCS to stable doses of ongoing medications can decrease MDD symptoms; however, benzodiazepines may interfere with TMS and tDCS response, and antipsychotics can interfere with TMS response. Pairing citalopram with TMS and sertraline with tDCS can lead to greater MDD symptom reduction compared to using these medications alone. Future studies need to enroll larger samples, include randomized controlled study designs, create more uniform protocols for combined treatment delivery, and explore mechanisms and predictors of change.

Investigating the impact of adjunctive priming repetitive transcranial magnetic stimulation in late-life depression: a pilot single-blind randomized control study

BACKGROUND

Conventional treatment methods have limited effectiveness in addressing late-life depression (LLD) that does not respond well. While a new approach called priming repetitive transcranial magnetic stimulation (rTMS) has shown promise in treating depression in adults, its effectiveness in LLD has not been explored. This study aimed to investigate the impact of priming rTMS on LLD.

METHODS

This study investigated the effectiveness of priming rTMS in 31 patients with LLD who did not improve after an adequate trial of antidepressants. Patients were randomly assigned to receive either active priming rTMS or sham priming rTMS. Active priming rTMS was delivered over the right dorsolateral prefrontal cortex for 10 sessions, lasting 31 minutes each, over a period of 2 weeks.

RESULTS

The group receiving active priming rTMS demonstrated greater improvements in scores on the Hamilton Rating Scale for Depression (p < 0.037; partial η2 0.141) and the Geriatric Depression Rating Scale (p < 0.045; partial η2 0.131) compared to the sham priming group, with a mild effect size. At the end of the second and fourth weeks, the priming rTMS group achieved a response rate of 50%, while the sham priming group had response rates of 26.7% and 6.7%, respectively. No adverse effects requiring intervention were observed.

CONCLUSION

Priming rTMS is well-tolerated for the treatment of LLD and not only reduces the severity of depression but also maintains the achieved response over time.

Equal remission rates and reduced length of hospital stay with twice-daily repetitive transcranial magnetic stimulation (rTMS) for major depression - A large naturalistic retrospective cohort association study

OBJECTIVES

Repetitive transcranial magnetic stimulation (rTMS) is a level 1a evidence-based treatment for major depression, but high cost of care and limited effectiveness in naturalistic cohorts have been lingering criticisms. This naturalistic, retrospective cohort analysis compares the effect of once and twice daily treatment protocols of rTMS using quality assurance data collected at an Australian private psychiatric hospital.

METHODS

A total of 210 inpatients self-selected into two groups receiving up to 30 sessions of either daily (n = 101) or twice daily (n = 109) 10 Hz rTMS to the left dorsolateral prefrontal cortex (DLPFC). The a priori primary outcome measure was remission rate as measured by pre and post treatment HAMD-17 scores. Length of hospital stay was a secondary post hoc outcome adopted due to the importance to cost of acute psychiatric care.

RESULTS

Remission rates were similar across groups, with 44.9% and 45.4% for twice daily and daily rTMS groups respectively, although these may be confounded by patient expectations, other treatments and medication changes given the naturalistic setting. The length of hospital stay was 10.11 days and 18.44 days for twice daily and daily rTMS respectively - the twice daily rTMS length of hospital stay was 45.1% shorter 95% CI [38.7% - 51.56%]. Dropout rates were high; Twenty-seven (24.77%) twice daily participants dropped out before 20 sessions were completed, and 35 (34.65%) of daily participants.

CONCLUSIONS

Twice daily 10 Hz left sided rTMS remission outcomes were similar to traditional once daily rTMS but required a shorter length of hospital stay. This finding has substantial cost of care implications. If these findings are independently replicated, twice daily rTMS may become the standard of care for inpatient rTMS.

Cognitive-affective processes and suicidality in response to repetitive transcranial magnetic stimulation for treatment resistant depression

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) can elicit 45-55 % response rates and may alleviate suicidality symptoms in treatment resistant depression (TRD). Blunted anticipatory reward sensitivity and negatively biased self-referential processing may predict trajectories of depressive and suicidality symptoms in rTMS for TRD and be modulated during treatment.

METHODS

Fifty-five individuals with TRD received four weeks of low-frequency rTMS applied to the right dorsolateral prefrontal cortex (LFR-rTMS) and were followed until 17 weeks post-baseline. Participants completed behavioral measures of anticipatory reward sensitivity and self-referential processing at baseline and five weeks post-baseline (approximately one-week post-treatment). We examined whether baseline anticipatory reward sensitivity and self-referential processing predicted trajectories of depressive and suicidality symptoms from baseline to follow-up and whether these cognitive-affective variables showed change from baseline to week five.

RESULTS

Anticipatory reward sensitivity and negative self-referential encoding at baseline were associated with higher overall depressive symptoms and suicidality from baseline to 17 weeks post-baseline. At week five, participants self-attributed a higher number of positive traits and a lower number of negative traits and had a lesser tendency to remember negative relative to positive traits they had self-attributed, compared to baseline.

LIMITATIONS

The specificity of these results to LFR-rTMS is unknown in the absence of a comparison group, and our relatively small sample size precluded the interpretation of null results.

CONCLUSIONS

Baseline blunted anticipatory reward sensitivity and negative biases in self-referential processing may be risk factors for higher depressive symptoms and suicidality during and after LFR-rTMS, and LFR-rTMS may modulate self-referential processing.

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.

Left frontal pole repetitive transcranial magnetic stimulation reduces cigarette cue-reactivity in correlation with verbal memory performance

BACKGROUND

Although left frontal pole (LFP) repetitive transcranial magnetic stimulation (rTMS) has been recently investigated for the treatment of different substance use disorders, there is no current evidence that it can effectively influence craving or clinical outcomes in smokers. A single session of 1 Hz rTMS over LFP is proposed to explore short-term effects of this protocol in tobacco use disorder.

METHODS

A pilot randomized trial compared 1 Hz rTMS of the LFP (n = 12) and primary motor cortex (n = 12) in a high-craving, severe nicotine dependence population (9 females, 15 males). A cigarette cue-reactivity paradigm with smoking-related and neutral visual stimuli was used for primary outcome measures. Chronic craving, dependence severity, impulsivity and cognitive measures were also obtained.

RESULTS

Compared to baseline, LFP rTMS significantly reduced cue-reactivity to both smoking-related and neutral cue types, while no change occurred in the motor cortex group. Reactivity to affectively neutral pictures was significantly reduced in the LFP vs. motor cortex analysis. There was one robust correlation between verbal memory recall score and reduction of neutral cue-reactivity.

CONCLUSIONS

LFP 1 Hz rTMS significantly reduced cigarette cue-reactivity. Association of change in cue-reactivity with verbal memory performance suggests a relationship between craving experiences and declarative memory systems that seems relevant to rTMS effects.

Optimized repetitive transcranial magnetic stimulation techniques for the treatment of major depression: A proof of concept study

Although effective in major depressive disorder (MDD), repetitive transcranial magnetic stimulation (rTMS) is costly and complex, limiting accessibility. To address this, we tested the feasibility of novel rTMS techniques with cost-saving opportunities, such as an open-room setting, large non-focal parabolic coils, and custom-built coil arms. We employed a low-frequency (LF) 1 Hz stimulation protocol (360 pulses per session), delivered on the most affordable FDA-approved device. MDD participants received an initial accelerated rTMS course (arTMS) of 6 sessions/day over 5 days (30 total), followed by a tapering course of daily sessions (up to 25) to decrease the odds of relapse. The self-reported Beck Depression Inventory II (BDI-II) was used to measure severity of depression. Forty-eight (48) patients completed the arTMS course. No serious adverse events occurred, and all patients reported manageable pain levels. Response and remission rates were 35.4% and 27.1% on the BDI-II, respectively, at the end of the tapering course. Repeated measures ANOVA showed significant changes of BDI-II scores over time. Even though our protocol will require further improvements, some of the concepts we introduced here could help guide the design of future trials aiming at increasing accessibility to rTMS.

Repetitive transcranial magnetic stimulation for major depressive disorder: basic principles and future directions

Repetitive transcranial magnetic stimulation (rTMS) is a safe and well-tolerated intervention for major depressive disorder (MDD). Over 150 randomized controlled trials (RCTs) have been carried out, and its efficacy has been confirmed in dozens of meta-analyses. Real world data has also confirmed the effectiveness of rTMS for MDD in clinical practice, with the most recent literature indicating response rates of 40-50% and remission rates of 25-30%. In this review, we first offer an historical perspective, followed by a review of basic principles, such as putative mechanisms, procedures and protocols, stimulation targets, efficacy and durability of response, side effects, and the placebo controversy. In the second part of this review, we first discuss solutions to increase accessibility to rTMS, such as modifications to treatment equipment, protocols and setting. We continue with possible means to further increase effectiveness, such as treatment personalization and extension. We conclude by addressing the scheduling issue, with accelerated rTMS (arTMS) as a possible solution.

rTMS modulates precuneus-hippocampal subregion circuit in patients with subjective cognitive decline

Hippocampal subregions (HIPsub) and their network connectivities are generally aberrant in patients with subjective cognitive decline (SCD). This study aimed to investigate whether repetitive transcranial magnetic stimulation (rTMS) could ameliorate HIPsub network connectivity by modulating one node of HIPsub network in SCD. In the first cohort, the functional connectivity (FC) of three HIPsub (i.e., hippocampal emotional, cognitive, and perceptual regions: HIPe, HIPc, and HIPp) were analyzed so as to identify alterations in HIPsub connectivity associated with SCD. Afterwards, a support vector machine (SVM) approach was applied using the alterations in order to evaluate to what extent we could distinguish SCD from healthy controls (CN). In the second cohort, a 2-week rTMS course of 5-day, once-daily, was used to activate the altered HIPsub network connectivity in a sham-controlled design. SCD subjects exhibited distinct patterns alterations of HIPsub network connectivity compared to CN in the first cohort. SVM classifier indicated that the abnormalities had a high power to discriminate SCD from CN, with 92.9% area under the receiver operating characteristic curve (AUC), 86.0% accuracy, 83.8% sensitivity and 89.1% specificity. In the second cohort, changes of HIPc connectivity with the left parahippocampal gyrus and HIPp connectivity with the left middle temporal gyrus demonstrated an amelioration of episodic memory in SCD after rTMS. In addition, SCD exhibited improved episodic memory after the rTMS course. rTMS therapy could improve the posterior hippocampus connectivity by modulating the precuneus in SCD. Simultaneous correction of the breakdown in HIPc and HIPp could ameliorate episodic memory in SCD. Thus, these findings suggested that rTMS manipulation of precuneus-hippocampal circuit might prevent disease progression by improving memory as the earliest at-risk state of Alzheimer’s disease in clinical trials and in practice.