Targeting Symptom-Specific Networks With Transcranial Magnetic Stimulation

Comparison between accelerated and standard or sham rTMS in the treatment of depression: A systematic review

Major depressive disorder (MDD) represents a major global health challenge, with a significant proportion of patients being resistant to drug treatment (TRD). Repetitive transcranial magnetic stimulation (rTMS) has shown promise in the treatment of MDD/TRD, with a single stimulation session per day for five days per week over several weeks (the "standard" protocol). The two main paradigms used are high-frequency rTMS and intermittent theta burst stimulation (iTBS) delivered to the left dorsolateral prefrontal cortex (DLPFC). Accelerated TMS (aTMS) protocols aim to make the treatment more effective, or at least more rapidly effective, by delivering more stimulations in a shorter time, which could also facilitate the implementation of the protocols for a larger number of patients. In this systematic literature review, articles comparing in the same study an aTMS protocol to a standard or sham rTMS protocol were retained for analysis. Thus, 23 articles were retained and the analysis focused on the efficacy of aTMS protocols used for the treatment of depression (MDD/TRD) as well as on the impact of various stimulation parameters, such as stimulation pattern, intersession interval, dosage, and methods of cortical targeting. Although some studies did not report significant differences between aTMS and standard or sham protocols, others suggested potential advantages of aTMS, such as twice-daily HF-rTMS of the left DLPFC or more intensive iTBS protocols with a long interval between two sessions and personalized cortical targeting. Our results highlight the influence of the number of sessions or pulses per session (dosage), the duration of the interval between sessions, and the precision of target localization (using image-guided neuronavigation) on therapeutic efficacy. However, limitations in sample size, few independent studies replicating the same methodology, and variability in the clinical profile of treated patients, given different definitions of treatment resistance or the presence of comorbidities, hamper definitive conclusions.

Multidimensional mechanisms of anxiety and depression in Parkinson's disease: Integrating neuroimaging, neurocircuits, and molecular pathways

Anxiety and depression are common non-motor symptoms of Parkinson's disease (PD) that significantly affect patients' quality of life. In recent years, our understanding of PD has advanced through multifaceted studies on the pathological mechanisms associated with anxiety and depression in PD. These classic psychiatric symptoms involve complex pathophysiology, with both distinct features and connections to the mechanisms underlying the aetiology of PD. Furthermore, the co-occurrence of anxiety and depression in PD blurs the boundaries between them. Therefore, a comprehensive summary of the pathogenic mechanisms associated with anxiety and depression will aid in better addressing the emergence of these classic psychiatric symptoms in PD. This article integrates neuroanatomical, neural projection, neurotransmitter, neuroinflammatory, brain-gut axis, neurotrophic, hypothalamic-pituitary-adrenal axis, and genetic perspectives to provide a comprehensive description of the core pathological alterations underlying anxiety and depression in PD, aiming to provide an up-to-date perspective and broader therapeutic prospects for PD patients suffering from anxiety or depression.

Chronic Intermittent Hypoxia-Induced Neural Injury: Pathophysiology, Neurodegenerative Implications, and Therapeutic Insights

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is a sleep-related respiratory disorder that poses a global threat to human health. Chronic intermittent hypoxia (CIH) is its main pathological feature. With the advancements in medical research, the study of CIH-induced neural injury has gained increasing attention. Studies have shown that CIH can lead to or aggravate neuroinflammation and apoptosis by increasing blood-brain barrier (BBB) permeability, promoting oxidative stress, activating glial cells, and triggering multiple signaling pathways, ultimately resulting in neural injury. These processes contribute to the development of Alzheimer's disease, Parkinson's disease, and stroke. This review aims to summarize the progress in CIH-induced neural injury and explore various underlying mechanisms, with the goal of providing new insights for the development of therapeutic interventions targeting CIH-related neural damage.

The current clinical approach to feeding and eating disorders aimed to increase personalization of management

Feeding and eating disorders (FEDs) are a heterogeneous grouping of disorders at the mind-body interface, with typical onset from childhood into emerging adulthood. They occur along a spectrum of disordered eating and compensatory weight management behaviors, and from low to high body weight. Psychiatric comorbidities are the norm. In contrast to other major psychiatric disorders, first-line treatments for FEDs are mainly psychological and/or nutrition-focused, with medications playing a minor adjunctive role. Patients, carers and clinicians all have identified personalization of treatment as a priority. Yet, for all FEDs, the evidence base supporting this personalization is limited. Importantly, disordered eating and related behaviors can have serious physical consequences and may put the patient's life at risk. In these cases, immediate safety and risk management considerations may at least for a period need to be prioritized over other efforts at personalization of care. This paper systematically reviews several key domains that may be relevant to the characterization of the individual patient with a FED aimed at personalization of management. These domains include symptom profile, clinical subtypes, severity, clinical staging, physical complications and consequences, antecedent and concomitant psychiatric conditions, social functioning and quality of life, neurocognition, social cognition and emotion, dysfunctional cognitive schemata, personality traits, family history, early environmental exposures, recent environmental exposures, stigma, and protective factors. Where possible, validated assessment measures for use in clinical practice are identified. The limitations of the current evidence are pointed out, and possible directions for future research are highlighted. These also include novel and emerging approaches aimed at providing more fine-grained and sophisticated ways to personalize treatment of FEDs, such as those that utilize neurobiological markers. We additionally outline remote measurement technologies designed to delineate patients' illness and recovery trajectories and facilitate development of novel intervention approaches.

A systematic review of structural and functional magnetic resonance imaging studies on the neurobiology of depressive symptoms in schizophrenia spectrum disorders

Depressive symptoms in Schizophrenia Spectrum Disorders (SSDs) negatively impact suicidality, prognosis, and quality of life. Despite this, efficacious treatments are limited, largely because the neural mechanisms underlying depressive symptoms in SSDs remain poorly understood. We conducted a systematic review to provide an overview of studies that investigated the neural correlates of depressive symptoms in SSDs using neuroimaging techniques. We searched MEDLINE, PsycINFO, EMBASE, Web of Science, and Cochrane Library databases from inception through June 19, 2023. Specifically, we focused on structural and functional magnetic resonance imaging (MRI), encompassing: (1) T1-weighted imaging measuring brain morphology; (2) diffusion-weighted imaging assessing white matter integrity; or (3) T2*-weighted imaging measures of brain function. Our search yielded 33 articles; 14 structural MRI studies, 18 functional (f)MRI studies, and 1 multimodal fMRI/MRI study. Reviewed studies indicate potential commonalities in the neurobiology of depressive symptoms between SSDs and major depressive disorders, particularly in subcortical and frontal brain regions, though confidence in this interpretation is limited. The review underscores a notable knowledge gap in our understanding of the neurobiology of depression in SSDs, marked by inconsistent approaches and few studies examining imaging metrics of depressive symptoms. Inconsistencies across studies' findings emphasize the necessity for more direct and comprehensive research focusing on the neurobiology of depression in SSDs. Future studies should go beyond "total score" depression metrics and adopt more nuanced assessment approaches considering distinct subdomains. This could reveal unique neurobiological profiles and inform investigations of targeted treatments for depression in SSDs.