Emerging Outlook on Personalized Neuromodulation for Depression: Insights from Tractography-Based Targeting

BACKGROUND

Deep brain stimulation (DBS) has shown individual promise in treating treatment resistant depression (TRD), but larger-scale trials have been less successful. Here, we create the largest meta-analysis with individual patient data (IPD) to date to explore if the use of tractography enhances the efficacy of DBS for TRD.

METHODS

We systematically reviewed 1823 articles, selecting 32 that contributed data from 366 patients. We stratified the IPD based on stimulation target and use of tractography. Utilizing two-way type III Analysis of Variance (ANOVA), Welch Two Sample t-tests, and mixed-effects linear regression models, we evaluated changes in depression severity 9-15 months post-surgery (1-Y) and at last follow-up (LFU) (4 weeks - 8 years) as assessed by depression scales.

RESULTS

Tractography was used for medial forebrain bundle (MFB, n=17/32), subcallosal cingulate (SCC, n=39/241), and ventral capsule/ventral striatum (VC/VS, n=3/41) targets; and not used for bed nucleus of stria terminalis (n=11), lateral habenula (n=10), and inferior thalamic peduncle (n=1). Across all patients, tractography significantly improved mean depression scores at 1-Y (p<0.001) and LFU (p=0.009). Within the target cohorts, tractography improved depression scores at 1-Y for both MFB and SCC, though significance was only met at the alpha = 0.1 level (SCC: β=15.8%, p=0.09; MFB: β=52.4%, p=0.10). Within the tractography cohort, MFB with tractography patients showed greater improvement than those with SCC with tractography (72.42±7.17% versus 54.78±4.08%) at 1-Y (p=0.044).

CONCLUSIONS

Our findings underscore the promise of tractography in DBS for TRD as a methodology for personalization of therapy, supporting its inclusion in future trials.

Exploring the multifaceted potential of (R)-ketamine beyond antidepressant applications

(R, S)- and (S)-ketamine have made significant progress in the treatment of treatment-resistant depression (TRD) and have become a research focus in recent years. However, they both have risks of psychomimetic effects, dissociative effects, and abuse liability, which limit their clinical use. Recent preclinical and clinical studies have shown that (R)-ketamine has a more efficient and lasting antidepressant effect with fewer side effects compared to (R, S)- and (S)-ketamine. However, a recent small-sample randomized controlled trial found that although (R)-ketamine has a lower incidence of adverse reactions in adult TRD treatment, its antidepressant efficacy is not superior to the placebo group, indicating its antidepressant advantage still needs further verification and clarification. Moreover, an increasing body of research suggests that (R)-ketamine might also have significant applications in the prevention and treatment of medical fields or diseases such as cognitive disorders, perioperative anesthesia, ischemic stroke, Parkinson's disease, multiple sclerosis, osteoporosis, substance use disorders, inflammatory diseases, COVID-19, and organophosphate poisoning. This article briefly reviews the mechanism of action and research on antidepressants related to (R)-ketamine, fully revealing its application potential and development prospects, and providing some references and assistance for subsequent expanded research.

A Retrospective Case-Control Study on the Differences in the Effectiveness of Theta-Burst Stimulation Therapy for Depression with and without Antidepressant Medication

Transcranial magnetic stimulation (TMS) therapy has few side effects and comparable therapeutic effects to antidepressant treatment, but few studies have introduced TMS therapy as an initial treatment for MDD. The objective of this study was to retrospectively compare the clinical outcomes between 50 MDD patients without antidepressants (i.e., TMS monotherapy) and 50 MDD patients with antidepressants plus TMS therapy, matched for age, sex, and depression severity. The presence or absence of antidepressant therapy in first-line treatment was determined via a detailed interview by psychiatrists. The study design was a retrospective observational case-control study using the TMS registry data. The key inclusion criteria were adult patients who met the diagnosis of MDD and received 20-30 sessions of intermittent theta-burst stimulation (iTBS) therapy to the left dorsolateral prefrontal cortex (DLPFC). In this study, the Montgomery-Åsberg Depression Rating Scale (MADRS) was used as the primary outcome measure. No significant group differences existed in the baseline MADRS total score between the unmedicated and medicated patient groups. Following TMS therapy, no significant group differences in response rate, remission rate, or relative total score change in the MADRS were observed. The main limitations were the retrospective design and the use of registry data as a source. Our findings suggest that TMS monotherapy may be as effective as TMS add-on therapy to antidepressants when used as the first-line therapy for MDD, but randomized controlled trials are needed.

Cost-effectiveness of psilocybin-assisted therapy for severe depression: exploratory findings from a decision analytic model

BACKGROUND

There is growing evidence to support the use of the psychedelic drug psilocybin for difficult-to-treat depression. This paper compares the cost-effectiveness of psilocybin-assisted psychotherapy (PAP) with conventional medication, cognitive behavioural therapy (CBT), and the combination of conventional medication and CBT.

METHODS

A decision model simulated patient events (response, remission, and relapse) following treatment. Data on probabilities, costs and quality-adjusted life years (QALYs) were derived from previous studies or from best estimates. Expected healthcare and societal costs and QALYs over a 6-month time period were calculated. Sensitivity analyses were used to address uncertainty in parameter estimates.

RESULTS

The expected healthcare cost of PAP varied from £6132 to £7652 depending on the price of psilocybin. This compares to £3528 for conventional medication alone, £4250 for CBT alone, and £4197 for their combination. QALYs were highest for psilocybin (0.310), followed by CBT alone (0.283), conventional medication alone (0.278), and their combination (0.287). Psilocybin was shown to be cost-effective compared to the other therapies when the cost of therapist support was reduced by 50% and the psilocybin price was reduced from its initial value to £400 to £800 per person. From a societal perspective, psilocybin had improved cost-effectiveness compared to a healthcare perspective.

CONCLUSIONS

Psilocybin has the potential to be a cost-effective therapy for severe depression. This depends on the level of psychological support that is given to patients receiving psilocybin and the price of the drug itself. Further data on long-term outcomes are required to improve the evidence base.

An Evaluation of the Effectiveness of Repetitive Transcranial Magnetic Stimulation (rTMS) for the Management of Treatment-Resistant Depression with Somatic Attributes: A Hospital-Based Study in Oman

Depressive illnesses in non-Western societies are often masked by somatic attributes that are sometimes impervious to pharmacological agents. This study explores the effectiveness of repetitive transcranial magnetic stimulation (rTMS) for people experiencing treatment-resistant depression (TRD) accompanied by physical symptoms. Data were obtained from a prospective study conducted among patients with TRD and some somatic manifestations who underwent 20 sessions of rTMS intervention from January to June 2020. The Hamilton Rating Scale for Depression (HAMD) was used for clinical evaluation. Data were analysed using descriptive and inferential techniques (multiple logistic regression) in SPSS. Among the 49 participants (mean age: 42.5 ± 13.3), there was a significant reduction in posttreatment HAMD scores compared to baseline (t = 10.819, p < 0.0001, and 95% CI = 8.574-12.488), indicating a clinical response. Approximately 37% of the patients responded to treatment, with higher response rates among men and those who remained in urban areas, had a history of alcohol use, and were subjected to the standard 10 HZ protocol. After adjusting for all extraneous variables, the rTMS protocol emerged as the only significant predictor of response to the rTMS intervention. To our knowledge, this is the first study to examine the effectiveness of rTMS in the treatment of somatic depression.

Efficacy and tolerability of minocycline in depressive patients with or without treatment-resistant: a meta-analysis of randomized controlled trials

Background

Minocycline, an antibiotic with anti-inflammatory, antioxidant, and neuroprotective properties, has been used for treating psychiatric disorders in research. This systematic review aimed to evaluate the efficacy and tolerability of minocycline in patients having depression with or without treatment-resistance.

Methods

Electronic databases including Embase, PubMed, and the Cochrane library were searched for relevant studies published up to October 17, 2022. The primary efficacy outcome was the change in depression severity scores and the secondary efficacy outcomes included the changes in Clinical Global Impression (CGI) and Beck Depression Inventory (BDI) scores and the incidence of response and partial response. Safety outcomes were evaluated based on the incidence of classified adverse events and all-cause discontinuation.

Results

Five studies with 374 patients were selected for analysis. The minocycline group demonstrated a significant reduction in depression severity scale (standardized mean difference [SMD]: -0.59, 95% confidence interval [CI]: -0.98 to -0.20, P = 0.003) and CGI (SMD: -0.28, 95% CI: -0.56 to -0.01, P = 0.042) scores; however, no statistical difference was found in terms of the BDI score, response, and partial response. No significant differences were found between the groups in terms of adverse events (other than dizziness) and discontinuation rates. Subgroup analysis showed that minocycline was also effective in reducing depression severity scores in treatment-resistant depression (SMD: -0.36, 95% CI: -0.64 to -0.09, P = 0.010). Subgroup analysis of Hamilton Depression Rating Scale (17-item) scores showed a statistical difference in response in patients with depression (relative risk: 2.51, 95% CI: 1.13 to 5.57, P = 0.024).

Conclusions

Minocycline may improve depressive symptoms and augment response to treatment in patients with depression irrespective of treatment-resistance. However, clinical trials with large sample sizes are warranted for evaluating long-term outcomes with minocycline.

Systematic review registration

https://inplasy.com/inplasy-2022-12-0051/.

Examining the neural mechanisms of rTMS: a naturalistic pilot study of acute and serial effects in pharmacoresistant depression

Introduction

Previous studies have demonstrated the effectiveness of therapeutic repetitive transcranial magnetic stimulation (rTMS) to treat pharmacoresistant depression. Nevertheless, these trials have primarily focused on the therapeutic and neurophysiological effects of rTMS following a long-term treatment course. Identifying brain-based biomarkers of early rTMS therapeutic response remains an important unanswered question. In this pilot study, we examined the effects of rTMS on individuals with pharmacoresistant depression using a graph-based method, called Functional Cortical Networks (FCN), and serial electroencephalography (EEG). We hypothesized that changes in brain activity would occur early in treatment course.

Methods

A total of 15 patients with pharmacoresistant depression underwent five rTMS sessions (5Hz over the left dorsolateral prefrontal cortex, 120%MT, up to 4,000 pulses/session). Five participants received additional rTMS treatment, up to 40 sessions. Resting EEG activity was measured at baseline and following every five sessions, using 64-channel EEG, for 10 minutes with eyes closed. An FCN model was constructed using time-varying graphs and motif synchronization. The primary outcome was acute changes in weighted-node degree. Secondary outcomes included serial FFT-based power spectral analysis and changes in depressive symptoms measured by the 9-Item Patient Health Questionnaire (PHQ-9) and the 30-item Inventory of Depressive Symptoms-Self Report (IDS-SR).

Results

We found a significant acute effect over the left posterior area after five sessions, as evidenced by an increase in weighted-node degree of 37,824.59 (95% CI, 468.20 to 75,180.98) and a marginal enhancement in the left frontal region (t (14) = 2.0820, p = 0.056). One-way repeated measures ANOVA indicated a significant decrease in absolute beta power over the left prefrontal cortex (F (7, 28) = 2.37, p = 0.048) following ten rTMS sessions. Furthermore, a significant clinical improvement was observed following five rTMS sessions on both PHQ-9 (t (14) = 2.7093, p = 0.017) and IDS-SR (t (14) = 2.5278, p = 0.024) and progressed along the treatment course.

Discussion

Our findings suggest that FCN models and serial EEG may contribute to a deeper understanding of mechanisms underlying rTMS treatment. Additional research is required to investigate the acute and serial effects of rTMS in pharmacoresistant depression and assess whether early EEG changes could serve as predictors of therapeutic rTMS response.

[Tiaoqi Jieyu acupuncture for treatment-resistant depression: a randomized controlled trial]

OBJECTIVE

To observe the effect of Tiaoqi Jieyu (regulating qi and relieving depression) acupuncture on the clinical symptoms of treatment-resistant depression (TRD), and to explore the relationship between the acupuncture pain sensitivity and symptom's improvement.

METHODS

A total of 78 patients with TRD were randomly divided into an observation group (39 cases, 3 cases dropped off) and a control group (39 cases, 4 cases dropped off). The patients in the control group were treated with medications according to the treatment plan of psychiatrists (at least one medication was 5-hydroxytryptamine reuptake inhibitor). On the basis of the control group, the patients in the observation group were treated with Tiaoqi Jieyu acupuncture, and Baihui (GV 20), Yintang (GV 24⁺), Yanglingquan (GB 34), Taichong (LR 3), Hegu (LI 4), Neiguan (PC 6), Yinlingquan (SP 9) and Zusanli (ST 36), etc. were selected. The acupuncture was given three times a week. Both groups were treated for 8 weeks. After 8-week treatment, the response rate of Hamilton depression scale-24 (HAMD-24) score after was evaluated in the two groups. The scores of HAMD-24 and Hamilton anxiety scale (HAMA) were compared between the two groups before treatment, after 4, 8-week treatment and 12 weeks after treatment (follow-up). After the first treatment and 8-week treatment, the visual analogue scale (VAS) score in the observation group was evaluated, and the correlation between VAS score after the first treatment and HAMD-24 score before treatment, between VAS score after the first treatment and the course of disease in the observation group was analyzed, and the correlation between difference of VAS after 8-week treatment and after the first treatment and difference of HAMD-24 score before treatment and after 8-week treatment was analyzed.

RESULTS

After 8-week treatment, the response rate of HAMD-24 score in the observation group was 52.8% (19/36), higher than 17.1% (6/35) in the control group (P<0.001). Compared before treatment, the scores of HAMD-24 and HAMA in the two groups were decreased after 4-week treatment, 8-week treatment and in follow-up (P<0.05), and those in the observation group were superior to the control group (P<0.05). After 8-week treatment, the acupuncture pain VAS score in the observation group was (5.28±2.13) points, which was higher than (3.33±1.62) points after the first treatment (P<0.001). There was a negative correlation between VAS score after the first treatment and HAMD-24 score before treatment in the observation group (r =-0.486, P=0.003); there was no correlation between acupuncture pain VAS score after the first treatment and the course of disease in the observation group (P>0.05). After 8-week treatment, there was a positive correlation between the difference of VAS score and the difference of HAMD-24 score in the observation group (r =0.514, P=0.001).

CONCLUSION

Tiaoqi Jieyu acupuncture could improve the depression and anxiety in patients with TRD, and the symptom's improvement is related to the recovery of acupuncture pain sensitivity.

Improving Patient-Centered Care for Veterans With Treatment-Resistant Depression Using Shared Decision-Making Tools

INTRODUCTION

Treatment-resistant depression (TRD) exists when patient depression continues without remission or reduction despite treatment. There are no standardized guidelines for identifying TRD, but one failed antidepressant treatment at an adequate dose and duration can constitute TRD, especially in cases of severe depression or suicidality. TRD rates for depressed patients average approximately 50% to 60% of the general population. These numbers are higher in the military population and are often complicated by comorbidities.

AIM

Chart audits revealed 68% of psychiatric clinic outpatient veterans met criteria for TRD. Only 25% of patients were being treated adequately for TRD, and 0% were offered other options for treatment. This project aimed to improve patient-centered TRD care at a veteran's hospital to 80% within 90 days.

METHODS

This quality improvement project was implemented using plan-do-study-act (PDSA) cycles. Interventions were tested over four rapid-cycle phases with improvements for screening, handouts, surveys, and team meetings over 8 weeks. Four core interventions were followed throughout the project: screening for TRD, right-care case management tracking, patient engagement with shared decision-making (SDM), and team engagement.

RESULTS

Starting from a baseline right-care score of 25%, the project attained an overall mean of 99.6% representing improved patient-centered TRD care and surpassing the 80% goal defined in the aim.

CONCLUSION

Overall TRD care was improved using SDM options and inter-clinic teamwork and communication.

TMS Database Registry Consortium Research Project in Japan (TReC-J) for Future Personalized Psychiatry

The registry project led by the Japanese Society for Clinical Transcranial Magnetic Stimulation (TMS) Research aims to establish a centralized database of epidemiological, clinical, and biological data on TMS therapy for refractory psychiatric disorders, including treatment-resistant depression, as well as to contribute to the elucidation of the therapeutic mechanism of TMS therapy and to the validation of its efficacy by analyzing and evaluating these data in a systematic approach. The objective of this registry project is to collect a wide range of complex data linked to patients with various neuropsychiatric disorders who received TMS therapy throughout Japan, and to make effective use of these data to promote cross-sectional and longitudinal exploratory observational studies. Research utilizing this registry project will be conducted in a multicenter, non-invasive, retrospective, and prospective observational research study design, regardless of the framework of insurance medical care, private practice, or clinical research. Through the establishment of the registry, which aims to make use of data, we will advance the elucidation of treatment mechanisms and identification of predictors of therapeutic response to TMS therapy for refractory psychiatric disorders on a more real-world research basis. Furthermore, as a future vision, we aim to develop novel neuromodulation medical devices, algorithms for predicting treatment efficacy, and digital therapeutics based on the knowledge generated from this TMS registry database.

Holding on or letting go? Patient experiences of control, context, and care in oral esketamine treatment for treatment-resistant depression: A qualitative study

BACKGROUND

Ketamine and its enantiomer esketamine represent promising new treatments for treatment-resistant depression (TRD). Esketamine induces acute, transient psychoactive effects. How patients perceive esketamine treatment, and which conditions facilitate optimal outcomes, remains poorly understood. Understanding patient perspectives on these phenomena is important to identify unmet needs, which can be used to improve (es)ketamine treatments.

AIMS

To explore the perspectives of TRD patients participating in "off label" oral esketamine treatment.

MATERIALS AND METHODS

In-depth interviews were conducted with 17 patients (11 women) after a six-week, twice-weekly esketamine treatment program, and subsequently after six months of at-home use. Interviews explored participants' perspectives, expectations, and experiences with esketamine treatment. Audio interviews were transcribed verbatim and analysed following an Interpretative Phenomenological Analysis (IPA) framework.

RESULTS

Key themes included overwhelming experiences; inadequate preparation; letting go of control; mood states influencing session experiences; presence and emotional support, and supportive settings. Patients' attempts to let go and give into vs. attempts to maintain control over occasionally overwhelming experiences was a central theme. Multiple factors influenced patients' ability to give into the experience and appeared to impact their mood and anxiety about future sessions, including level of preparation and education, physical and emotional support, and setting during the session.

CONCLUSION

Better preparation beforehand, an optimized treatment setting, and emotional and psychological support during (es)ketamine sessions can help patients to "let go" and may lead to better quality of care and outcomes. Recommendations to improve quality of patient care in (es)ketamine treatment are provided, including suggestions for the training of nurses and other support staff.

Antidepressant-resistant depression is characterized by reduced short- and long-interval cortical inhibition

BACKGROUND

Major depressive disorder (MDD) is highly heterogeneous and can be classified as treatment-resistant depression (TRD) or antidepressant-responsive depression (non-TRD) based on patients' responses to antidepressant treatment. Methods for distinguishing between TRD and non-TRD are critical clinical concerns. Deficits of cortical inhibition (CI) have been reported to play an influential role in the pathophysiology of MDD. Whether TRD patients' CI is more impaired than that of non-TRD patients remains unclear.

METHODS

Paired-pulse transcranial magnetic stimulation (ppTMS) was used to measure cortical inhibitory function including GABAA- and GABAB-receptor-related CI and cortical excitatory function including glutamate-receptor-related intracortical facilitation (ICF). We recruited 36 healthy controls (HC) and 36 patients with MDD (non-TRD, n = 16; TRD, n = 20). All participants received evaluations for depression severity and ppTMS examinations. Non-TRD patients received an additional ppTMS examination after 3 months of treatment with the SSRI escitalopram.

RESULTS

Patients with TRD exhibited reduced short-interval intracortical inhibition (SICI) and long-interval intracortical inhibition (LICI), as shown by abnormally higher estimates, than those with non-TRD or HC (F = 11.030, p < 0.001; F = 10.309, p < 0.001, respectively). After an adequate trial of escitalopram treatment, the LICI of non-TRD reduced significantly (t = - 3.628, p < 0.001), whereas the ICF remained lower than that of HC and showed no difference from pretreatment non-TRD.

CONCLUSIONS

TRD was characterized by relatively reduced CI, including both GABAA- and GABAB-receptor-mediated neurons while non-TRD preserved partial CI. In non-TRD, SSRIs may mainly modulate GABAB-receptor-related LICI. Our findings revealed distinguishable features of CI in antidepressant-resistant and responsive major depression.

Buprenorphine: prospective novel therapy for depression and PTSD

BACKGROUND

Depression and post-traumatic stress disorder (PTSD) are leading causes of disability and loss of life by suicide. Currently, there are less than satisfactory medical solutions to treat these mental disorders. Here, we explore recent preclinical and clinical studies demonstrating the potential of using buprenorphine to treat major depressive disorder, treatment-resistant depression, and PTSD.

METHOD

Bibliographic databases were searched to include preclinical and clinical studies demonstrating the therapeutic potential of buprenorphine and the involvement of the kappa opioid receptor (KOR) in mediating these effects.

RESULTS

Original clinical studies examining the effectiveness of buprenorphine to treat depression were mixed. The majority of participants in the PTSD studies were males and suffer from chronic pain and/or substance use disorders. Nonetheless, these recent studies and analyses established proof of concept warranting farther investigations. Additionally, KOR likely mediates the antidepressant and some of the anxiolytic effects of buprenorphine. Still, it appears that the full spectrum of buprenorphine's beneficial effects might be due to activity at other opioid receptors as well.

CONCLUSIONS

Pharmaceuticals' abilities to treat medical conditions directly relates to their ability to act upon the endogenous biological systems related to the conditions. Thus, these recent findings are likely a reflection of the central role that the endogenous opioid system has in these mental illnesses. Further studies are necessary to study the involvement of endogenous opioid systems, and specifically KOR, in mediating buprenorphine's beneficial effects and the ability to treat these medical conditions while minimizing risks for misuse and diversion.

Anatomical Connectivity-Based Strategy for Targeting Transcranial Magnetic Stimulation as Antidepressant Therapy

OBJECTIVES

Abnormal activity of the subgenual anterior cingulate cortex (sACC) is implicated in depression, suggesting the sACC as a potentially effective target for therapeutic modulation in cases resistant to conventional treatments (treatment-resistant depression, TRD). We hypothesized that areas in the prefrontal cortex (PFC) with direct fiber connections to the sACC may be particularly effective sites for treatment using transcranial magnetic stimulation (TMS). The aim of this study was to identify PFC sites most strongly connected to the sACC.

METHODS

Two neuroimaging data sets were used to construct anatomic and functional connectivity maps using sACC as the seed region. Data set 1 included magnetic resonance (MR) images from 20 healthy controls and Data set 2 included MR images from 15 TRD patients and 15 additional healthy controls. PFC voxels with maximum values in the mean anatomic connection probability maps were identified as optimal sites for TMS.

RESULTS

Both right and left PFC contained sites strongly connected to the sACC, but the coordinates (in Montreal Neurological Institute space) of peak anatomic connectivity differed slightly between hemispheres. The left PFC site connected directly to the sACC both anatomically and functionally, while the right PFC site was functionally connected to the posterior cingulate cortex (PCC).

CONCLUSIONS

Both left and right PFC are functionally connected to regions implicated in depression, the sACC and PCC, respectively. These bilateral PFC sites may be effective TMS targets to treat TRD.

Abnormal Neural Basis of Emotional Conflict Control in Treatment-Resistant Depression

Emotional conflict has received increased attention as a research topic. The objective of this study is to confirm that the processing of emotional conflict is impaired in treatment-resistant depression (TRD). We compared the event-related potentials of 17 patients with TRD and 17 healthy controls during the face-word Stroop task, which is an effective way of assessing the effects of emotional conflict directly. Compared with healthy controls, the accuracy scores of the TRD patients were lower in both "congruent stimuli" and "incongruent stimuli" conditions, and their response times were longer. The TRD patients also had larger N2 amplitudes over the frontal region, regardless of stimulus condition, which might reflect that TRD patients pay more attention to emotional information. A larger P3 amplitude over the frontal region for "incongruent stimuli minus congruent stimuli" was also found among patients with TRD, which indicates interference effects in the Stroop task. The results of this study provide novel behavioral and neurophysiological evidence of anomalies in cognitive inhibition among patients with TRD using the word-face task. These findings not only improve our understanding of deficient inhibition in TRD, but also pave the way for a cognitive neuropsychiatric model of depression.

Meta-Review of Metanalytic Studies with Repetitive Transcranial Magnetic Stimulation (rTMS) for the Treatment of Major Depression

Background:

Major Depression (MD) and treatment-resistant depression (TRD) are worldwide leading causes of disability and therapeutic strategies for these impairing and prevalent conditions include pharmacological augmentation strategies and brain stimulation techniques. In this perspective, repetitive transcranial magnetic stimulation (rTMS) is a non-invasive brain stimulation technique with a favorable profile of tolerability which, despite being recently approved by the Food and Drug Administration (FDA) for the treatment of patients with medication-refractory unipolar depression, still raises some doubts about most effective parameters of stimulation.

Methods:

A literature search was performed using PubMed for the years 2001 through February 2011 in order to review meta-analytic studies assessing efficacy and safety issues for rTMS in depressive disorders. Fifteen meta-analyses were identified and critically discussed in order to provide an updated and comprehensive overview of the topic with specific emphasis on potentially optimal parameters of stimulation.

Results:

First meta-analyses on the efficacy of rTMS for the treatment of MD and TRD have shown mixed results. On the other hand, more recent meta-analytic studies seem to support the antidepressant efficacy of the technique to a greater extent, also in light of longer periods of stimulation (e.g. > 2 weeks).

Conclusion:

rTMS seems to be an effective and safe brain stimulation technique for the treatment of medication refractory depression. Nevertheless, further studies are needed to better define specific stimulation-related issues, such as duration of treatment as well as durability of effects and predictors of response.