Changes in Functional Connectivity Predict Outcome of Repetitive Transcranial Magnetic Stimulation Treatment of Major Depressive Disorder.

Repetitive transcranial magnetic stimulation (rTMS) treatment of major depressive disorder (MDD) is associated with changes in brain functional connectivity (FC). These changes may be related to the mechanism of action of rTMS and explain the variability in clinical outcome. We examined changes in electroencephalographic FC during the first rTMS treatment in 109 subjects treated with 10 Hz stimulation to left dorsolateral prefrontal cortex. All subjects subsequently received 30 treatments and clinical response was defined as ≥40% improvement in the inventory of depressive symptomatology-30 SR score at treatment 30. Connectivity change was assessed with coherence, envelope correlation, and a novel measure, alpha spectral correlation (αSC). Machine learning was used to develop predictive models of outcome for each connectivity measure, which were compared with prediction based upon early clinical improvement. Significant connectivity changes were associated with clinical outcome (P < 0.001). Machine learning models based on αSC yielded the most accurate prediction (area under the curve, AUC = 0.83), and performance improved when combined with early clinical improvement measures (AUC = 0.91). The initial rTMS treatment session produced robust changes in FC, which were significant predictors of clinical outcome of a full course of treatment for MDD.

Dorsolateral prefrontal γ-aminobutyric acid in patients with treatment-resistant depression after transcranial magnetic stimulation measured with magnetic resonance spectroscopy

Background: The therapeutic mechanism of repetitive transcranial magnetic stimulation (rTMS) for treatment-resistant depression (TRD) may involve modulation of γ-aminobutyric acid (GABA) levels. We used proton magnetic resonance spectroscopy (MRS) to assess changes in GABA levels at the site of rTMS in the left dorsolateral prefrontal cortex (DLPFC). Methods: In 26 adults with TRD, we used Mescher­Garwood point-resolved spectroscopy (MEGA-PRESS) spectral-editing MRS to measure GABA in the left DLPFC before and after standard clinical treatment with rTMS. All participants but 1 were medicated, including 12 patients on GABA agonist agents. Results: Mean GABA in the DLPFC increased 10.0% (p = 0.017) post-rTMS in the overall sample. As well, GABA increased significantly in rTMS responders (n = 12; 23.6%, p = 0.015) but not in nonresponders (n = 14; 4.1%, p = not significant). Changes in GABA were not significantly affected by GABAergic agonists, but clinical response was less frequent (p = 0.005) and weaker (p = 0.035) in the 12 participants who were receiving GABA agonists concomitant with rTMS treatment. Limitations: This study had an open-label design in a population receiving naturalistic treatment. Conclusion: Treatment using rTMS was associated with increases in GABA levels at the stimulation site in the left DLPFC, and the degree of GABA change was related to clinical improvement. Participants receiving concomitant treatment with a GABA agonist were less likely to respond to rTMS. These findings were consistent with earlier studies showing the effects of rTMS on GABA levels and support a GABAergic model of depression.

Predictors of response to synchronized transcranial magnetic stimulation for major depressive disorder.

BACKGROUND: Synchronized transcranial magnetic stimulation (sTMS) is a new modality to reduce symptoms of major depressive disorder (MDD). sTMS uses rotating neodymium magnets to deliver low-field stimulation matched to the individual alpha frequency (IAF). A previous multisite study showed that sTMS significantly reduced MDD symptoms in the per-protocol sample. To this end, we evaluated clinical features associated with optimal sTMS outcomes. METHODS: Using the per-protocol sample (n = 120) from the parent sham-controlled trial, we performed univariate and stepwise linear regression to identify predictors of response after 6 weeks of sTMS. A subsample (n = 83) that entered a 4-week open/active continuation phase also was examined. Candidate variables included age, sex, comorbid anxiety, number of failed antidepressants in the current depressive episode, MDD severity (17-item Hamilton Depression Rating Scale; HAMD17), anxiety symptom severity (HAMD17 anxiety/somatization factor), and IAF. RESULTS: We found that greater baseline depressive (p < 0.001) and anxiety (p < 0.001) symptom severity were associated with better response to active sTMS, whereas fewer failed antidepressant trials predicted superior response to sham (p < 0.001). MDD severity and antidepressant resistance predicted outcomes in open/active phase sTMS; lower IAF predicted poorer response in participants who received 10 weeks of active sTMS (p = 0.001). CONCLUSIONS: Participants with greater severity of depression and higher anxiety had superior responses to active sTMS, whereas treatment naïve individuals exhibited a greater response to sham. These results lend support to the primary efficacy findings, and support further investigation of sTMS as a therapeutic noninvasive brain stimulation modality.

Benefits and Harms of Cranial Electrical Stimulation for Chronic Painful Conditions, Depression, Anxiety, and Insomnia: A Systematic Review.

Background: Cranial electrical stimulation (CES) is increasingly popular as a treatment, yet its clinical benefit is unclear. Purpose: To review evidence about the benefits and harms of CES for adult patients with chronic painful conditions, depression, anxiety, and insomnia. Data Sources: Several databases from inception to 10 October 2017 without language restrictions and references from experts, prior reviews, and manufacturers. Study Selection: Randomized controlled trials of CES versus usual care or sham CES that reported pain, depression, anxiety, or sleep outcomes in any language. Data Extraction: Single-reviewer extraction checked by another; dual independent quality assessment; strength-of-evidence grading by the first author with subsequent group discussion. Data Synthesis: Twenty-eight articles from 26 randomized trials met eligibility criteria. The 2 trials that compared CES with usual care were small, and neither reported a statistically significant benefit in pain or anxiety outcomes for patients with fibromyalgia or anxiety, respectively. Fourteen trials with sham or placebo controls involving patients with painful conditions, such as headache, neuromuscular pain, or musculoskeletal pain, had conflicting results. Four trials done more than 40 years ago and 1 from 2014 provided low-strength evidence of a possible modest benefit compared with sham treatments in patients with anxiety and depression. Trials in patients with insomnia (n = 2), insomnia and anxiety (n = 1), or depression (n = 3) had inconclusive or conflicting results. Low-strength evidence suggested that CES does not cause serious side effects. Limitation: Most trials had small sample sizes and short durations; all had high risk of bias due to inadequate blinding. Conclusion: Evidence is insufficient that CES has clinically important effects on fibromyalgia, headache, neuromusculoskeletal pain, degenerative joint pain, depression, or insomnia; low-strength evidence suggests modest benefit in patients with anxiety and depression. Primary Funding Source: Veterans Affairs Quality Enhancement Research Initiative. (PROSPERO: CRD42016023951).

Brain Activity and Clinical Outcomes in Adults With Depression Treated With Synchronized Transcranial Magnetic Stimulation: An Exploratory Study.

BACKGROUND: Synchronized transcranial magnetic stimulation (sTMS) imparts low-amplitude magnetic stimulation matched to each patient's individual alpha frequency. It may act through entrainment of brain oscillations. OBJECTIVES: To explore sTMS effects on neurophysiology with electroencephalography (EEG) in adults with major depressive disorder. METHODS: As an ancillary study to a clinical trial of sTMS, EEGs were recorded at baseline and at one and six weeks of treatment. Associations between EEG measures and clinical symptoms were examined. RESULTS: Absolute and relative power measures did not differ significantly between active and sham groups and did not change significantly over time. Changes occurring over six weeks in alpha current source density at anterior and central midline voxels were significantly correlated with changes in symptoms in subjects treated with active but not sham sTMS. CONCLUSION: Neurophysiologic measures suggest that active but not sham sTMS engages brain targets, and that target engagement is related to treatment outcome.

Can neurophysiologic measures serve as biomarkers for the efficacy of repetitive transcranial magnetic stimulation treatment of major depressive disorder?

Repetitive transcranial magnetic stimulation (rTMS) is an effective treatment for Major Depressive Disorder (MDD). There are clinical data that support the efficacy of many different approaches to rTMS treatment, and it remains unclear what combination of stimulation parameters is optimal to relieve depressive symptoms. Because of the costs and complexity of studies that would be necessary to explore and compare the large number of combinations of rTMS treatment parameters, it would be useful to establish reliable surrogate biomarkers of treatment efficacy that could be used to compare different approaches to treatment. This study reviews the evidence that neurophysiologic measures of cortical excitability could be used as biomarkers for screening different rTMS treatment paradigms. It examines evidence that: (1) changes in excitability are related to the mechanism of action of rTMS; (2) rTMS has consistent effects on measures of excitability that could constitute reliable biomarkers; and (3) changes in excitability are related to the outcomes of rTMS treatment of MDD. An increasing body of evidence indicates that these neurophysiologic measures have the potential to serve as reliable biomarkers for screening different approaches to rTMS treatment of MDD.

Transcranial Magnetic Stimulation for Obsessive-Compulsive Disorder: An Updated Systematic Review and Meta-analysis.

BACKGROUND: Transcranial magnetic stimulation (TMS) is a promising noninvasive brain stimulation intervention. Transcranial magnetic stimulation has been proposed for obsessive-compulsive disorder (OCD) with auspicious results. OBJECTIVE: To assess the efficacy of TMS for OCD in randomized clinical trials (RCTs). METHODS: Systematic review using MEDLINE and EMBASE from the first RCT available until March 11, 2016. The main outcome was the Hedges g for continuous scores for Yale-Brown Obsessive Compulsive Scale in a random-effects model. Heterogeneity was evaluated with the I and the χ test. Publication bias was evaluated using the Begg funnel plot. Metaregression was performed using the random-effects model modified by Knapp and Hartung. RESULTS: We included 15 RCTs (n = 483), most had small-to-modest sample sizes. Comparing active versus sham TMS, active stimulation was significantly superior for OCD symptoms (Hedges g = 0.45; 95% confidence interval, 0.2-0.71). The funnel plot showed that the risk of publication bias was low and between-study heterogeneity was low (I = 43%, P = 0.039 for the χ test). Metaregression showed no particular influence of any variable on the results. CONCLUSIONS: Transcranial magnetic stimulation active was superior to sham stimulation for the amelioration of OCD symptoms. Trials had moderate heterogeneity results, despite different protocols of stimulation used. Further RCTs with larger sample sizes are fundamentally needed to clarify the precise impact of TMS in OCD symptoms.

Trigeminal Nerve Stimulation for Comorbid Posttraumatic Stress Disorder and Major Depressive Disorder.

OBJECTIVES: External stimulation of the trigeminal nerve (eTNS) is an emerging neuromodulation therapy for epilepsy and depression. Preliminary studies suggest it has an excellent safety profile and is associated with significant improvements in seizures and mood. Neuroanatomical projections of the trigeminal system suggest eTNS may alter activity in structures regulating mood, anxiety, and sleep. In this proof-of-concept trial, the effects of eTNS were evaluated in adults with posttraumatic stress disorder (PTSD) and comorbid unipolar major depressive disorder (MDD) as an adjunct to pharmacotherapy for these commonly co-occurring conditions. MATERIALS AND METHODS: Twelve adults with PTSD and MDD were studied in an eight-week open outpatient trial (age 52.8 [13.7 sd], 8F:4M). Stimulation was applied to the supraorbital and supratrochlear nerves for eight hours each night as an adjunct to pharmacotherapy. Changes in symptoms were monitored using the PTSD Patient Checklist (PCL), Hamilton Depression Rating Scale (HDRS-17), Quick Inventory of Depressive Symptomatology (QIDS-C), and the Quality of Life Enjoyment and Satisfaction Questionnaire (Q-LES-Q). RESULTS: Over the eight weeks, eTNS treatment was associated with significant decreases in PCL (p = 0.003; median decrease of 15 points; effect size d 1.5), HDRS-17 (p < 0.001; 42% response rate, 25% remission; d 2.1), and QIDS-C scores (p < 0.001; d 1.8), as well as an improvement in quality of life (Q-LES-Q, p < 0.01). eTNS was well tolerated with few treatment emergent adverse events. CONCLUSIONS: Significant improvements in PTSD and depression severity were achieved in the eight weeks of acute eTNS treatment. This novel approach to wearable brain stimulation may have use as an adjunct to pharmacotherapy in these disorders if efficacy and tolerability are confirmed with additional studies.

Role of pill-taking, expectation and therapeutic alliance in the placebo response in clinical trials for major depression.

BACKGROUND: Pill-taking, expectations and therapeutic alliance may account for much of the benefit of medication and placebo treatment for major depressive disorder (MDD). Aims To examine the effects of medication, placebo and supportive care on treatment outcome, and the relationships of expectations and therapeutic alliance to improvement. METHOD: A total of 88 participants were randomised to 8 weeks of treatment with supportive care alone or combined with double-blind treatment with placebo or antidepressant medication. Expectations of medication effectiveness, general treatment effectiveness and therapeutic alliance were measured (trial registration at ClinicalTrials.gov: NCT00200902). RESULTS: Medication or placebo plus supportive care were not significantly different but had significantly better outcome than supportive care alone. Therapeutic alliance predicted response to medication and placebo; expectations of medication effectiveness at enrolment predicted only placebo response. CONCLUSIONS: Pill treatment yielded better outcome than supportive care alone. Medication expectations uniquely predicted placebo treatment outcome and were formed by time of enrolment, suggesting that they were shaped by prior experiences outside the clinical trial.

Rostral anterior cingulate activity in major depressive disorder: state or trait marker of responsiveness to medication?

High rostral anterior cingulate cortex (rACC) activity has been shown to predict antidepressant treatment response; however, it is unclear whether this is a fixed versus variable marker of responsiveness. The authors measured rACC theta current density in 22 subjects 5 weeks before and again immediately before 5 weeks of blinded treatment with sertraline. Mixed-effects regression analysis found that the relationship between response and rACC activity depended significantly on the timing of the rACC assessment; rACC activity measured immediately before treatment was a significantly better predictor of response. rACC activity may constitute a variable "state" indicator of responsiveness to antidepressants.

Trigeminal nerve stimulation in major depressive disorder: acute outcomes in an open pilot study.

Most patients with major depressive disorder (MDD) do not recover with initial pharmacotherapy, and many pursue combination treatments. Combining a medication with neuromodulation offers an alternative to purely pharmacologic strategies. In prior open and double-blind controlled trials for drug-resistant epilepsy, adjunctive external trigeminal nerve stimulation (eTNS) was found to be safe and well tolerated, to significantly reduce seizures, and to be associated with an improvement in depressive symptoms. Here, we present a comprehensive description of the first open pilot investigation in MDD. In this 8-week trial, eleven adults with unipolar MDD received nightly stimulation (V(1) branch). All entered with moderate to severe symptom levels despite at least two antidepressant medication trials in this episode. All the eleven adults completed the acute trial, without serious adverse events. Symptoms of depression improved significantly, whether assessed with clinician- or self-rated scales (all p < 0.01; effect sizes d 1.0-1.8), as did quality of life (p < 0.02). Four of the 11 achieved remission. These improvements from nightly adjunctive eTNS in treatment-resistant depression merit replication under double-blind conditions.

Transcranial magnetic stimulation (TMS) for major depression: a multisite, naturalistic, observational study of quality of life outcome measures in clinical practice.

BACKGROUND: Transcranial magnetic stimulation (TMS) is an effective and safe therapy for major depressive disorder (MDD). This study assessed quality of life (QOL) and functional status outcomes for depressed patients after an acute course of TMS. METHODS: Forty-two, U.S.-based, clinical TMS practice sites treated 307 outpatients with a primary diagnosis of MDD and persistent symptoms despite prior adequate antidepressant pharmacotherapy. Treatment parameters were based on individual clinical considerations and followed the labeled procedures for use of the approved TMS device. Patient self-reported QOL outcomes included change in the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) and the EuroQol 5-Dimensions (EQ-5D) ratings from baseline to end of the acute treatment phase. RESULTS: Statistically significant improvement in functional status on a broad range of mental health and physical health domains was observed on the SF-36 following acute TMS treatment. Similarly, statistically significant improvement in patient-reported QOL was observed on all domains of the EQ-5D and on the General Health Perception and Health Index scores. Improvement on these measures was observed across the entire range of baseline depression symptom severity. CONCLUSION: These data confirm that TMS is effective in the acute treatment of MDD in routine clinical practice settings. This symptom benefit is accompanied by statistically and clinically meaningful improvements in patient-reported QOL and functional status outcomes.

Relationship between medical student perceptions of mistreatment and mistreatment sensitivity.

BACKGROUND: National statistics reveal that efforts to reduce medical student mistreatment have been largely ineffective. Some hypothesize that as supervisors gain skills in professionalism, medical students become more sensitive. AIMS: The purpose of this study was to determine if medical student perceptions of mistreatment are correlated with mistreatment sensitivity. METHOD: At the end of their third year, 175 medical students completed an Abuse Sensitivity Questionnaire, focused on student assessment of hypothetical scenarios which might be perceived as abusive, and the annual Well-Being Survey, which includes measurement of incident rates of mistreatment. It was hypothesized that those students who identified the scenarios as abusive would also be more likely to perceive that they had been mistreated. RESULTS: Student perceptions of mistreatment were not statistically correlated with individual's responses to the scenarios or to a statistically derived abuse sensitivity variable. There were no differences in abuse sensitivity by student age or ethnicity. Women were more likely than men to consider it "harsh" to be called incompetent during rounds (p < 0.0005). CONCLUSION: This study provides preliminary evidence that challenges the hypothesis that medical students who perceive mistreatment by their superiors are simply more sensitive.

Transcranial magnetic stimulation (TMS) for major depression: a multisite, naturalistic, observational study of acute treatment outcomes in clinical practice.

BACKGROUND: Few studies have examined the effectiveness of transcranial magnetic stimulation (TMS) in real-world clinical practice settings. METHODS: Forty-two US-based clinical TMS practice sites treated 307 outpatients with Major Depressive Disorder (MDD), and persistent symptoms despite antidepressant pharmacotherapy. Treatment was based on the labeled procedures of the approved TMS device. Assessments were performed at baseline, week 2, at the point of maximal acute benefit, and at week 6 when the acute course extended beyond 6 weeks. The primary outcome was change in the Clinician Global Impressions-Severity of Illness from baseline to end of acute phase. Secondary outcomes were change in continuous and categorical outcomes on self-report depression scales (9-Item Patient Health Questionnaire [PHQ-9], and Inventory of Depressive Symptoms-Self Report [IDS-SR]). RESULTS: Patients had a mean ± SD age of 48.6 ± 14.2 years and 66.8% were female. Patients received an average of 2.5 (± 2.4) antidepressant treatments of adequate dose and duration without satisfactory improvement in this episode. There was a significant change in CGI-S from baseline to end of treatment (-1.9 ± 1.4, P < .0001). Clinician-assessed response rate (CGI-S) was 58.0% and remission rate was 37.1%. Patient-reported response rate ranged from 56.4 to 41.5% and remission rate ranged from 28.7 to 26.5%, (PHQ-9 and IDS-SR, respectively). CONCLUSION: Outcomes demonstrated response and adherence rates similar to research populations. These data indicate that TMS is an effective treatment for those unable to benefit from initial antidepressant medication.

Trigeminal nerve stimulation in major depressive disorder: first proof of concept in an open pilot trial.

Modulation of brain activity via trigeminal nerve stimulation is an emerging therapy in drug-resistant epilepsy. This cranial nerve also projects to structures implicated in depression (such as the nucleus tractus solitarius and locus coeruleus). We examined the effects of external trigeminal nerve stimulation in major depressive disorder as an adjunct to pharmacotherapy. Five adults (mean age 49.6, SD 10.9, three females and two males) participated in an 8-week open-label outpatient trial; all had persistent symptoms despite adequate pharmacotherapy, with a mean score on the 28-item Hamilton Depression Rating Scale of 25.4 (SD=3.9) at entry. Nightly stimulation over the V(1) branch was well tolerated. Both the clinician-rated 28-item Hamilton Depression Rating Scale (P=0.006) and the self-rated Beck Depression Inventory (P=0.0004) detected significant symptomatic improvement. This novel neuromodulation approach may have use as an adjunct to pharmacotherapy in major depressive disorder. Additional larger trials are needed to delineate efficacy and tolerability with greater reliability.

Rostral anterior cingulate cortex activity and early symptom improvement during treatment for major depressive disorder.

In treatment trials for major depressive disorder (MDD), early symptom improvement is predictive of eventual clinical response. Clinical response may also be predicted by elevated pretreatment theta (4-7Hz) current density in the rostral anterior cingulate (rACC) and medial orbitofrontal cortex (mOFC). We investigated the relationship between pretreatment EEG and early improvement in predicting clinical outcome in 72 MDD subjects across three placebo-controlled treatment trials. Subjects were randomized to receive fluoxetine, venlafaxine, or placebo. Theta current density in the rACC and mOFC was computed with Low-Resolution Brain Electromagnetic Tomography (LORETA). An analysis of covariance examining week-8 Hamilton Depression Rating Scale (HamD) percent change, showed a significant effect of week-2HamD percent change, and a significant three-way interaction of week-2HamD percent change×treatment×rACC. Medication subjects with robust early improvement showed almost no relationship between rACC theta current density and final clinical outcome. However, in subjects with little early improvement, rACC activity showed a strong relationship with clinical outcome. The model examining the mOFC showed a trend in the three-way interaction. A combination of pretreatment rACC activity and early symptom improvement may be useful for predicting treatment response.