Frontostriatal salience network expansion in individuals in depression.

Decades of neuroimaging studies have shown modest differences in brain structure and connectivity in depression, hindering mechanistic insights or the identification of risk factors for disease onset1. Furthermore, whereas depression is episodic, few longitudinal neuroimaging studies exist, limiting understanding of mechanisms that drive mood-state transitions. The emerging field of precision functional mapping has used densely sampled longitudinal neuroimaging data to show behaviourally meaningful differences in brain network topography and connectivity between and in healthy individuals2-4, but this approach has not been applied in depression. Here, using precision functional mapping and several samples of deeply sampled individuals, we found that the frontostriatal salience network is expanded nearly twofold in the cortex of most individuals with depression. This effect was replicable in several samples and caused primarily by network border shifts, with three distinct modes of encroachment occurring in different individuals. Salience network expansion was stable over time, unaffected by mood state and detectable in children before the onset of depression later in adolescence. Longitudinal analyses of individuals scanned up to 62 times over 1.5 years identified connectivity changes in frontostriatal circuits that tracked fluctuations in specific symptoms and predicted future anhedonia symptoms. Together, these findings identify a trait-like brain network topology that may confer risk for depression and mood-state-dependent connectivity changes in frontostriatal circuits that predict the emergence and remission of depressive symptoms over time.

Antidepressant Augmentation versus Switch in Treatment-Resistant Geriatric Depression.

BACKGROUND: The benefits and risks of augmenting or switching antidepressants in older adults with treatment-resistant depression have not been extensively studied. METHODS: We conducted a two-step, open-label trial involving adults 60 years of age or older with treatment-resistant depression. In step 1, patients were randomly assigned in a 1:1:1 ratio to augmentation of existing antidepressant medication with aripiprazole, augmentation with bupropion, or a switch from existing antidepressant medication to bupropion. Patients who did not benefit from or were ineligible for step 1 were randomly assigned in step 2 in a 1:1 ratio to augmentation with lithium or a switch to nortriptyline. Each step lasted approximately 10 weeks. The primary outcome was the change from baseline in psychological well-being, assessed with the National Institutes of Health Toolbox Positive Affect and General Life Satisfaction subscales (population mean, 50; higher scores indicate greater well-being). A secondary outcome was remission of depression. RESULTS: In step 1, a total of 619 patients were enrolled; 211 were assigned to aripiprazole augmentation, 206 to bupropion augmentation, and 202 to a switch to bupropion. Well-being scores improved by 4.83 points, 4.33 points, and 2.04 points, respectively. The difference between the aripiprazole-augmentation group and the switch-to-bupropion group was 2.79 points (95% CI, 0.56 to 5.02; P = 0.014, with a prespecified threshold P value of 0.017); the between-group differences were not significant for aripiprazole augmentation versus bupropion augmentation or for bupropion augmentation versus a switch to bupropion. Remission occurred in 28.9% of patients in the aripiprazole-augmentation group, 28.2% in the bupropion-augmentation group, and 19.3% in the switch-to-bupropion group. The rate of falls was highest with bupropion augmentation. In step 2, a total of 248 patients were enrolled; 127 were assigned to lithium augmentation and 121 to a switch to nortriptyline. Well-being scores improved by 3.17 points and 2.18 points, respectively (difference, 0.99; 95% CI, -1.92 to 3.91). Remission occurred in 18.9% of patients in the lithium-augmentation group and 21.5% in the switch-to-nortriptyline group; rates of falling were similar in the two groups. CONCLUSIONS: In older adults with treatment-resistant depression, augmentation of existing antidepressants with aripiprazole improved well-being significantly more over 10 weeks than a switch to bupropion and was associated with a numerically higher incidence of remission. Among patients in whom augmentation or a switch to bupropion failed, changes in well-being and the occurrence of remission with lithium augmentation or a switch to nortriptyline were similar. (Funded by the Patient-Centered Outcomes Research Institute; OPTIMUM ClinicalTrials.gov number, NCT02960763.).

Influence of Large-Scale Brain State Dynamics on the Evoked Response to Brain Stimulation.

Understanding how spontaneous brain activity influences the response to neurostimulation is crucial for the development of neurotherapeutics and brain-computer interfaces. Localized brain activity is suggested to influence the response to neurostimulation, but whether fast-fluctuating (i.e., tens of milliseconds) large-scale brain dynamics also have any such influence is unknown. By stimulating the prefrontal cortex using combined transcranial magnetic stimulation (TMS) and electroencephalography, we examined how dynamic global brain state patterns, as defined by microstates, influence the magnitude of the evoked brain response. TMS applied during what resembled the canonical Microstate C was found to induce a greater evoked response for up to 80 ms compared with other microstates. This effect was found in a repeated experimental session, was absent during sham stimulation, and was replicated in an independent dataset. Ultimately, ongoing and fast-fluctuating global brain states, as probed by microstates, may be associated with intrinsic fluctuations in connectivity and excitation-inhibition balance and influence the neurostimulation outcome. We suggest that the fast-fluctuating global brain states be considered when developing any related paradigms.

Effects of repetitive transcranial magnetic stimulation on individual variability of resting-state functional connectivity in major depressive disorder.

BACKGROUND: Repetitive transcranial magnetic stimulation (rTMS) is an effective treatment for major depressive disorder (MDD), but substantial heterogeneity in outcomes remains. We examined a potential mechanism of action of rTMS to normalize individual variability in resting-state functional connectivity (rs-fc) before and after a course of treatment. METHODS: Variability in rs-fc was examined in healthy controls (baseline) and individuals with MDD (baseline and after 4-6 weeks of rTMS). Seed-based connectivity was calculated to 4 regions associated with MDD: left dorsolateral prefrontal cortex (DLPFC), right subgenual anterior cingulate cortex (sgACC), bilateral insula, and bilateral precuneus. Individual variability was quantified for each region by calculating the mean correlational distance of connectivity maps relative to the healthy controls; a higher variability score indicated a more atypical/idiosyncratic connectivity pattern. RESULTS: We included data from 66 healthy controls and 252 individuals with MDD in our analyses. Patients with MDD did not show significant differences in baseline variability of rs-fc compared with controls. Treatment with rTMS increased rs-fc variability from the right sgACC and precuneus, but the increased variability was not associated with clinical outcomes. Interestingly, higher baseline variability of the right sgACC was significantly associated with less clinical improvement (p = 0.037, uncorrected; did not survive false discovery rate correction).Limitations: The linear model was constructed separately for each region of interest. CONCLUSION: This was, to our knowledge, the first study to examine individual variability of rs-fc related to rTMS in individuals with MDD. In contrast to our hypotheses, we found that rTMS increased the individual variability of rs-fc. Our results suggest that individual variability of the right sgACC and bilateral precuneus connectivity may be a potential mechanism of rTMS.

Poor Sleep is Common in Treatment-Resistant Late-life Depression and Associated With Poorer Antidepressant Response: Findings From the OPTIMUM Clinical Trial.

BACKGROUND: Adults with treatment-resistant late-life depression (TRLLD) have high rates of sleep problems; however, little is known about the occurrence and change in sleep during pharmacotherapy of TRLLD. This analysis examined: (1) the occurrence of insufficient sleep among adults with TRLLD; (2) how sleep changed during pharmacotherapy; and (3) whether treatment outcomes differed among participants with persistent insufficient sleep, worsened sleep, improved sleep, or persistent sufficient sleep. METHODS: Secondary analysis of data from 634 participants age 60+ years in the OPTIMUM clinical trial for TRLLD. Sleep was assessed using the sleep item from the Montgomery-Asberg Depression Rating Scale at the beginning (week-0) and end (week-10) of treatment. The analyses examined whether treatment outcomes differed among participants with persistent insufficient sleep, worsened sleep, improved sleep, or persistent sufficient sleep during depression treatment. RESULTS: About half (51%, n = 323) of participants reported insufficient sleep at baseline. Both persistent insufficient sleep (25%, n = 158) and worsened sleep (10%, n = 62) during treatment were associated with antidepressant nonresponse. Participants who maintained sufficient sleep (26%, n = 164) or who improved their sleep (n = 25%, n = 158) were three times more likely to experience a depression response than those with persistent insufficient sleep or worsened sleep. CONCLUSION: Insufficient sleep is common in TRLLD and it is associated with poorer treatment response to antidepressants.

A randomized sham-controlled trial of high-dosage accelerated intermittent theta burst rTMS in major depression: study protocol.

BACKGROUND: Intermittent theta burst stimulation (iTBS), a novel form of repetitive transcranial magnetic stimulation (rTMS), can be administered in 1/10th of the time of standard rTMS (~ 3 min vs. 37.5 min) yet achieves similar outcomes in depression. The brief nature of the iTBS protocol allows for the administration of multiple iTBS sessions per day, thus reducing the overall course length to days rather than weeks. This study aims to compare the efficacy and tolerability of active versus sham iTBS using an accelerated regimen in patients with treatment-resistant depression (TRD). As a secondary objective, we aim to assess the safety, tolerability, and treatment response to open-label low-frequency right-sided (1 Hz) stimulation using an accelerated regimen in those who do not respond to the initial week of treatment. METHODS: Over three years, approximately 230 outpatients at the Centre for Addiction and Mental Health and University of British Columbia Hospital, meeting diagnostic criteria for unipolar MDD, will be recruited and randomized to a triple blind sham-controlled trial. Patients will receive five consecutive days of active or sham iTBS, administered eight times daily at 1-hour intervals, with each session delivering 600 pulses of iTBS. Those who have not achieved response by the week four follow-up visit will be offered a second course of treatment, regardless of whether they initially received active or sham stimulation. DISCUSSION: Broader implementation of conventional iTBS is limited by the logistical demands of the current standard course consisting of 4-6 weeks of daily treatment. If our proposed accelerated iTBS protocol enables patients to achieve remission more rapidly, this would offer major benefits in terms of cost and capacity as well as the time required to achieve clinical response. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04255784.

Canadian Network for Mood and Anxiety Treatments (CANMAT) 2023 Update on Clinical Guidelines for Management of Major Depressive Disorder in Adults: Réseau canadien pour les traitements de l'humeur et de l'anxiété (CANMAT) 2023 : Mise à jour des lignes directrices cliniques pour la prise en charge du trouble dépressif majeur chez les adultes.

BACKGROUND: The Canadian Network for Mood and Anxiety Treatments (CANMAT) last published clinical guidelines for the management of major depressive disorder (MDD) in 2016. Owing to advances in the field, an update was needed to incorporate new evidence and provide new and revised recommendations for the assessment and management of MDD in adults. METHODS: CANMAT convened a guidelines editorial group comprised of academic clinicians and patient partners. A systematic literature review was conducted, focusing on systematic reviews and meta-analyses published since the 2016 guidelines. Recommendations were organized by lines of treatment, which were informed by CANMAT-defined levels of evidence and supplemented by clinical support (consisting of expert consensus on safety, tolerability, and feasibility). Drafts were revised based on review by patient partners, expert peer review, and a defined expert consensus process. RESULTS: The updated guidelines comprise eight primary topics, in a question-and-answer format, that map a patient care journey from assessment to selection of evidence-based treatments, prevention of recurrence, and strategies for inadequate response. The guidelines adopt a personalized care approach that emphasizes shared decision-making that reflects the values, preferences, and treatment history of the patient with MDD. Tables provide new and updated recommendations for psychological, pharmacological, lifestyle, complementary and alternative medicine, digital health, and neuromodulation treatments. Caveats and limitations of the evidence are highlighted. CONCLUSIONS: The CANMAT 2023 updated guidelines provide evidence-informed recommendations for the management of MDD, in a clinician-friendly format. These updated guidelines emphasize a collaborative, personalized, and systematic management approach that will help optimize outcomes for adults with MDD.

Corticospinal excitability is highest at the early rising phase of sensorimotor µ-rhythm.

Alpha oscillations are thought to reflect alternating cortical states of excitation and inhibition. Studies of perceptual thresholds and evoked potentials have shown the scalp EEG negative phase of the oscillation to correspond to a short-lasting low-threshold and high-excitability state of underlying visual, somatosensory, and primary motor cortex. The negative peak of the oscillation is assumed to correspond to the state of highest excitability based on biophysical considerations and considerable effort has been made to improve the extraction of a predictive signal by individually optimizing EEG montages. Here, we investigate whether it is the negative peak of sensorimotor µ-rhythm that corresponds to the highest corticospinal excitability, and whether this is consistent between individuals. In 52 adult participants, a standard 5-channel surface Laplacian EEG montage was used to extract sensorimotor µ-rhythm during transcranial magnetic stimulation (TMS) of primary motor cortex. Post-hoc trials were sorted from 800 TMS-evoked motor potentials (MEPs) according to the pre-stimulus EEG (estimated instantaneous phase) and MEP amplitude (as an index of corticospinal excitability). Different preprocessing transformations designed to improve the accuracy by which µ-alpha phase predicts excitability were also tested. By fitting a sinusoid to the MEP amplitudes, sorted according to pre-stimulus EEG-phase, we found that excitability was highest during the early rising phase, at a significant delay with respect to the negative peak by on average 45° or 10 ms. The individual phase of highest excitability was consistent across study participants and unaffected by two different EEG-cleaning methods that utilize 64 channels to improve signal quality by compensating for individual noise level and channel covariance. Personalized transformations of the montage did not yield better prediction of excitability from µ-alpha phase. The relationship between instantaneous phase of a brain oscillation and fluctuating cortical excitability appears to be more complex than previously hypothesized. In TMS of motor cortex, a standard surface Laplacian 5-channel EEG montage is effective in extracting a predictive signal and the phase corresponding to the highest excitability appears to be consistent between individuals. This is an encouraging result with respect to the clinical potential of therapeutic personalized brain interventions in the motor system. However, it remains to be investigated, whether similar results can be obtained for other brain areas and brain oscillations targeted with EEG and TMS.

Effect of prior pharmacotherapy on remission with sequential bilateral theta-burst versus standard bilateral repetitive transcranial magnetic stimulation in treatment-resistant late-life depression.

Repetitive transcranial magnetic stimulation (rTMS) is used for treatment of late-life depression. In the FOUR-D study, sequential bilateral theta-burst stimulation (TBS) had comparable remission rates to standard bilateral rTMS. Data were analysed from the FOUR-D trial to compare remission rates between two types of rTMS based on the number and class of prior medication trials. The remission rate was higher in participants with ≤1 previous trial (43.9%) than in participants with 2 previous trials (26.5%) or ≥3 previous trials (24.6%; χ² = 6.36, d.f. = 2, P = 0.04). Utilising rTMS earlier in late-life depression may lead to better outcomes.

A cross-sectional study of cognitive performance in bipolar disorder across the lifespan: the cog-BD project.

BACKGROUND: Neuroprogressive models of the trajectory of cognitive dysfunction in patients with bipolar disorder (BD) have been proposed. However, few studies have explored the relationships among clinical characteristics of BD, cognitive dysfunction, and aging. METHODS: We conducted a cross-sectional analysis in euthymic participants with the MATRICS Cognitive Consensus Battery, the Trail Making Test B, the Stroop Test, and the Wechsler Test of Adult Reading. Age- and gender-equated control participants without a mental disorder ['Healthy Controls' - HC)] were assessed similarly. We compared cognitive performance both globally and in seven domains in four groups: younger BD (age ⩽49 years; n = 70), older BD (age ⩾50 years; n = 48), younger HC (n = 153), and older HC (n = 44). We also compared the BD and HC groups using age as a continuous measure. We controlled for relevant covariates and applied a Bonferroni correction. RESULTS: Our results support both an early impairment ('early hit') model and an accelerated aging model: impairment in attention/vigilance, processing speed, and executive function/working memory were congruent with the accelerated aging hypothesis whereas impairment in verbal memory was congruent with an early impairment model. BD and HC participants exhibited similar age-related decline in reasoning/problem solving and visuospatial memory. There were no age- or diagnosis-related differences in social cognition. CONCLUSION: Our findings support that different cognitive domains are affected differently by BD and aging. Longitudinal studies are needed to explore trajectories of cognitive performance in BD across the lifespan.

Recruiting for a Randomized Clinical Trial for Late-Life Depression During COVID-19: Outcomes of Provider Referrals Versus Facebook Self-Referrals.

OBJECTIVE: To evaluate the effectiveness of online recruitment for a clinical trial of pharmacotherapy for late-life depression during COVID-19. METHODS: The authors calculated the yield, defined as recruitment leading to randomization (enrollment), from provider referrals versus Facebook self-referrals; compared characteristics and drop-out rates of participants from each source; and analyzed correlations between stringency of public health restrictions and referrals from each source over time. RESULTS: Provider referrals had a significantly higher yield (10 of 33 referrals; 30.3%) versus Facebook self-referrals (14 of 323; 4.3%) (p <0.00001). Participants self-referred from Facebook had significantly more education; otherwise, both groups had similar characteristics and drop-out rates. While public health stringency was negatively correlated with provider referrals (ρ = -0.32) and positively correlated with Facebook self-referrals (ρ = 0.39), neither association reached statistical significance. CONCLUSION: Online recruitment may improve access to clinical research for older depressed adults. Future studies should evaluate cost-effectiveness and potential barriers such as computer literacy.

Late-Life Depression is Associated With Increased Levels of GDF-15, a Pro-Aging Mitokine.

OBJECTIVE: In older adults, major depressive disorder (MDD) is associated with accelerated physiological and cognitive aging, generating interest in uncovering biological pathways that may be targetable by interventions. Growth differentiation factor-15 (GDF-15) plays a significant role in biological aging via multiple biological pathways relevant to age and age-related diseases. Elevated levels of GDF-15 correlate with increasing chronological age, decreased telomerase activity, and increased mortality risk in older adults. We sought to evaluate the circulating levels of GDF-15 in older adults with MDD and its association with depression severity, physical comorbidity burden, age of onset of first depressive episode, and cognitive performance. DESIGN: This study assayed circulating levels of GDF-15 in 393 older adults (mean ± SD age 70 ± 6.6 years, male:female ratio 1:1.54), 308 with MDD and 85 non-depressed comparison individuals. RESULTS: After adjusting for confounding variables, depressed older adults had significantly higher GDF-15 serum levels (640.1 ± 501.5 ng/mL) than comparison individuals (431.90 ± 223.35 ng/mL) (t=3.75, d.f.= 391, p=0.0002). Among depressed individuals, those with high GDF-15 had higher levels of comorbid physical illness, lower executive cognitive functioning, and higher likelihood of having late-onset depression. CONCLUSION: Our results suggest that depression in late life is associated with GDF-15, a marker of amplified age-related biological changes. GDF-15 is a novel and potentially targetable biological pathway between depression and accelerated aging, including cognitive aging.

A pilot randomized sham controlled trial of bilateral iTBS for depression and executive function in older adults.

INTRODUCTION: Executive function deficits (EFD) in late life depression (LLD) are associated with poor outcomes. Dysfunction of the cognitive control network (CCN) has been posited in the pathophysiology of LLD with EFD. METHODS: Seventeen older adults with depression and EFD were randomized to iTBS or sham for 6 weeks. Intervention was delivered bilaterally using a recognized connectivity target. RESULTS: A total of 89% (17/19) participants completed all study procedures. No serious adverse events occurred. Pre to post-intervention change in mean Montgomery-Asberg-depression scores was not different between iTBS or sham, p = 0.33. No significant group-by-time interaction for Montgomery-Asberg Depression rating scale scores (F 3, 44  = 0.51; p = 0.67) was found. No significant differences were seen in the effects of time between the two groups on executive measures: Flanker scores (F 1, 14  = 0.02, p = 0.88), Dimensional-change-card-sort scores F 1, 14  = 0.25, p = 0.63, and working memory scores (F 1, 14  = 0.98, p = 0.34). The Group-by-time interaction effect for functional connectivity (FC) within the Fronto-parietal-network was not significant (F 1, 14  = 0.36, p = 0.56). No significant difference in the effect-of-time between the two groups was found on FC within the Cingulo-opercular-network (F 1, 14  = 0, p = 0.98). CONCLUSION: Bilateral iTBS is feasible in LLD. Preliminary results are unsupportive of efficacy on depression, executive function or target engagement of the CCN. A future Randomized clinical trial requires a larger sample size with stratification of cognitive and executive variables and refinement in the target engagement.

Assessing the Longitudinal Relationship between Theta-Gamma Coupling and Working Memory Performance in Older Adults.

Theta-gamma coupling (TGC) is a neurophysiologic mechanism that supports working memory (WM). TGC is associated with N-back performance, a WM task. Similar to TGC, theta and alpha event-related synchronization (ERS) and desynchronization (ERD) are also associated with WM. Few studies have examined the longitudinal relationship between WM performance and TGC, ERS, or ERD. This study aimed to determine if changes in WM performance are associated with changes in TGC (primary aim), as well as theta and alpha ERS or ERD over 6 to 12 weeks. Participants included 62 individuals aged 60 and older with no neuropsychiatric conditions or with remitted Major Depressive Disorder (MDD) and no cognitive disorders. TGC, ERS, and ERD were assessed using electroencephalography (EEG) during the N-back task (3-back condition). There was an association between changes in 3-back performance and changes in TGC, alpha ERD and ERS, and theta ERS in the control group. In contrast, there was only a significant association between changes in 3-back performance and changes in TGC in the subgroup with remitted MDD. Our results suggest that the relationship between WM performance and TGC is stable over time, while this is not the case for changes in theta and alpha ERS and ERD.

Impact of COVID-19 on electroconvulsive therapy practice across Canadian provinces during the first wave of the pandemic.

BACKGROUND: Electroconvulsive therapy (ECT) is a procedural treatment that is potentially life-saving for some patients with severe psychiatric illness. At the start of the global coronavirus disease 2019 (COVID-19) pandemic, ECT practice was remarkably disrupted, putting vulnerable individuals at increased risk of symptom exacerbation and death by suicide. This study aimed to capture the self-reported experiences of psychiatrists based at healthcare facilities across Canadian provinces who were delivering ECT treatments during the first phase of the COVID-19 pandemic (i.e., from mid-March 2020 to mid-May 2020). METHODS: A multidisciplinary team of experts developed a survey focusing on five domains: ECT unit operations, decision-making, hospital resources, ECT procedure, and mitigating patient impact. Responses were collected from psychiatrists providing ECT at 67 ECT centres in Canada, grouped by four geographical regions (Ontario, Quebec, Atlantic Canada, and Western Canada). RESULTS: Clinical operations of ECT programs were disrupted across all four regions - however, centres in Atlantic Canada were able to best preserve outpatient and maintenance care, while centres in Western Canada were able to best preserve inpatient and acute care. Similarly, Atlantic and Western Canada demonstrated the best decision-making practices of involving the ECT team and clinical ethicists in the development of pandemic-related guidelines. Across all four regions, ECT practice was affected by the redeployment of professionals, the shortage of personal protective equipment, and the need to enforce social distancing. Attempts to introduce modifications to the ECT delivery room and minimize bag-valve-mask ventilation were consistently reported. All four regions developed a new patient prioritization framework, and Western Canada, notably, aimed to provide ECT to only the most severe cases. CONCLUSIONS: The results suggest that ECT provision was disproportionately affected across different parts of Canada. Possible factors that could explain these interregional differences include population, distribution of urban vs. rural areas, pre-pandemic barriers in access to ECT, number of cases, ability to control the spread of infection, and the general reduction in physicians' activities across different areas of health care. Studying these factors in the future will inform how medical centres should respond to public health emergencies and pandemic-related circumstances in the context of procedural treatments.

Competencies for Repetitive Transcranial Magnetic Stimulation in Postgraduate Medical Education: Expert Consensus Using a Modified Delphi Process.

BACKGROUND: Repetitive transcranial magnetic stimulation (rTMS) is recommended in Canadian guidelines as a first-line treatment for major depressive disorder. With the shift towards competency-based medical education, it remains unclear how to determine when a resident is considered competent in applying knowledge of rTMS to patient care. Given inconsistencies between postgraduate training programmes with regards to training requirements, defining competencies will improve the standard of care in rTMS delivery. OBJECTIVE: The goal of this study was to develop competencies for rTMS that can be implemented into a competency-based training curriculum in postgraduate training programmes. METHODS: A working group drafted competencies for postgraduate psychiatry trainees. Fourteen rTMS experts from across Canada were invited to participate in the modified Delphi process. RESULTS: Ten experts participated in all three rounds of the modified Delphi process. A total of 20 items reached a consensus. There was improvement in the Cronbach's alpha over the rounds of modified Delphi process (Cronbach's alpha increased from 0.554 to 0.824) suggesting improvement in internal consistency. The intraclass correlation coefficient (ICC) increased from 0.543 to 0.805 suggesting improved interrater agreement. CONCLUSIONS: This modified Delphi process resulted in expert consensus on competencies to be acquired during postgraduate medical education programmes where a learner is training to become competent as a consultant and/or practitioner in rTMS treatment. This is a field that still requires development, and it is expected that as more evidence emerges the competencies will be further refined. These results will help the development of other curricula in interventional psychiatry.

Effects of repetitive paired associative stimulation on brain plasticity and working memory in Alzheimer's disease: a pilot randomized double-blind-controlled trial.

DESIGN: Pilot randomized double-blind-controlled trial of repetitive paired associative stimulation (rPAS), a paradigm that combines transcranial magnetic stimulation (TMS) of the dorsolateral prefrontal cortex (DLPFC) with peripheral median nerve stimulation. OBJECTIVES: To study the impact of rPAS on DLPFC plasticity and working memory performance in Alzheimer's disease (AD). METHODS: Thirty-two patients with AD (females = 16), mean (SD) age = 76.4 (6.3) years were randomized 1:1 to receive a 2-week (5 days/week) course of active or control rPAS. DLPFC plasticity was assessed using single session PAS combined with electroencephalography (EEG) at baseline and on days 1, 7, and 14 post-rPAS. Working memory and theta-gamma coupling were assessed at the same time points using the N-back task and EEG. RESULTS: There were no significant differences between the active and control rPAS groups on DLPFC plasticity or working memory performance after the rPAS intervention. There were significant main effects of time on DLPFC plasticity, working memory, and theta-gamma coupling, only for the active rPAS group. Further, on post hoc within-group analyses done to generate hypotheses for future research, as compared to baseline, only the rPAS group improved on post-rPAS day 1 on all three indices. Finally, there was a positive correlation between working memory performance and theta-gamma coupling. CONCLUSIONS: This study did not show a beneficial effect of rPAS for DLPFC plasticity or working memory in AD. However, post hoc analyses showed promising results favoring rPAS and supporting further research on this topic. (Clinicaltrials.gov-NCT01847586).

Association between lean muscle mass and treatment-resistant late-life depression in the IRL-GRey randomized controlled trial.

OBJECTIVE: To investigate the relationship between lean muscle mass and treatment response in treatment-resistant late-life depression (TR-LLD). We hypothesized that lower lean muscle mass would be associated with older age, higher physical comorbidities, higher depressive symptom severity, and poorer treatment response. DESIGN: Secondary analysis of a randomized, placebo-controlled trial. SETTING: Three academic hospitals in the United States and Canada. PARTICIPANTS: Adults aged 60+ years with major depressive disorder who did not remit following open treatment with venlafaxine extended-release (XR) (n = 178). MEASUREMENTS: We estimated lean muscle mass using dual-energy X-ray absorptiometry (DEXA) scans prior to and following randomized treatment with aripiprazole or placebo added to venlafaxine XR. Multivariate regressions estimated influence of demographic and clinical factors on baseline lean muscle mass, and whether baseline lean muscle mass was associated with treatment response, adjusted for treatment arm. RESULTS: Low lean muscle mass was present in 22 (12.4%) participants. Older age and female sex, but not depressive symptom severity, were independently associated with lower lean muscle mass at baseline. Marital status, baseline depressive symptom severity, and treatment group were associated with improvement of depressive symptoms in the randomized treatment phase. Baseline lean muscle mass was not associated with improvement, regardless of treatment group. CONCLUSION: As expected, older age and female sex were associated with lower lean muscle mass in TR-LLD. However, contrary to prior results in LLD, lean muscle mass was not associated with depression severity or outcome. This suggests that aripiprazole augmentation may be useful for TR-LLD, even in the presence of anomalous body composition.clinicaltrials.gov Identifier: NCT00892047.

Differential Placebo Responses for Pharmacotherapy and Neurostimulation in Late-Life Depression.

BACKGROUND: The magnitude of the placebo response depends on both the modality used as the "placebo" and the intervention with which it is compared, both of which can complicate the interpretation of randomized controlled trials (RCTs) for depression in late life. Given that neurostimulation and pharmacotherapy are among the most common interventions studied for late-life depression, comparing the relative placebo responses in studies of these interventions can aid interpretation of relative effect sizes. MATERIALS AND METHODS: We analyzed data from two RCTs of adults aged ≥60 years in an episode of treatment-resistant major depression, one comparing aripiprazole and matching placebo pills and the other comparing deep repetitive transcranial magnetic stimulation (rTMS) and sham rTMS. In both RCTs, depression was assessed using the 17-item Hamilton Depression Rating Scale (HDRS-17). The primary comparison occurred after four weeks using analysis of covariance (ANCOVA) of HDRS-17 scores in participants who received placebo pills or sham rTMS. Relevant covariates included years of education, duration of depressive episode, and baseline HDRS-17 score. RESULTS: Accounting for covariates, there was a larger reduction of HDRS-17 after four weeks in the sham rTMS group (estimated marginal mean ± SE: -5.90 ± 1.45; 95% CI: [-8.82, 2.98]) than in the placebo pills group (-1.07 ± 1.45; [-3.98, 1.85]). There were no significant differences between these groups in the binary outcome analysis of response and remission rates at four weeks or any outcome at trial end point comparison. CONCLUSIONS: Sham rTMS may have a larger placebo response than placebo pills early in the treatment of older adults with treatment-resistant depression. Differential placebo responses should be considered in both the interpretation and design of RCTs.

A Critical Appraisal of Evidence on the Efficacy and Safety of Serotonergic Psychedelic Drugs as Emerging Antidepressants: Mind the Evidence Gap.

PURPOSE/BACKGROUND: There has been resurgence of interest in the therapeutic use of serotonergic ("classic") psychedelics in major depressive disorder (MDD) and end-of-life distress. This commentary offers a critical appraisal of current evidence for antidepressant effects of classic psychedelics from contemporary clinical trials and highlights pitfalls that should be addressed before clinical translation. METHODS/PROCEDURES: A narrative review was conducted to identify clinical trials of serotonergic psychedelics for the treatment of MDD and end-of-life distress. Trials published between January 1990 and May 2022 were identified on PubMed using combinations of search terms. FINDINGS/RESULTS: Psilocybin, lysergic acid diethylamide, and ayahuasca have clinical trials to evaluate antidepressant effects. Two studies showed preliminary positive effects of single-dose ayahuasca for treatment-resistant depression. Similar results were seen in lysergic acid diethylamide for end-of-life distress. Small randomized clinical trials (RCTs) of psilocybin combined with psychotherapy showed superiority to waitlist controls and comparable efficacy and safety to an active comparator in MDD, with additional RCTs showing efficacy in end-of-life distress. Adverse events associated with psychedelics were reported as mild and transient. Small homogenous samples, expectancy bias, functional unblinding, and lack of consensus and standardization of psychotherapy are major limitations of all studies. IMPLICATIONS/CONCLUSIONS: Given the methodological limitations of published RCTs, the evidence supporting the efficacy and safety of serotonergic psychedelics for depression is currently of low level. Future research should assess the role of expectancy and psychedelic effects in moderating and mediating treatment response. Innovative trial designs are needed to overcome functional unblinding. For now, psychedelics should remain experimental interventions used within clinical trials.