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Psychoneuroendocrinology Feb 2022Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis has been implicated in the development of major depressive disorder (MDD) in adulthood. Less work has... (Meta-Analysis)
Meta-Analysis Review
INTRODUCTION
Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis has been implicated in the development of major depressive disorder (MDD) in adulthood. Less work has focused on the role of the HPA axis in depression in adolescence and young adulthood globally. The aim of this study was to conduct a systematic review and meta-analysis of worldwide research investigating the relationship between cortisol, a measure of HPA axis activity, and MDD in adolescence and young adulthood.
METHOD
We searched MEDLINE, PsycINFO, Cochrane Database of Systematic Reviews, Web of Science, Lilacs, African Journals Online, and Global Health for studies which examined the relationship between cortisol and MDD in global youth (10-24 years old).
RESULTS
Twenty-six studies were included in the systematic review and 14 were eligible for the meta-analysis, but only one study included young adults in their sample. Results from the meta-analysis demonstrated that elevated morning, but not evening, cortisol levels was prospectively associated with later MDD development in adolescence and young adulthood. However, morning cortisol levels did not significantly differ between healthy controls and individuals with MDD in cross-sectional studies. Afternoon cortisol and cortisol stress response also did not differ between adolescents with MDD and healthy controls. Qualitative synthesis of the three studies examining nocturnal cortisol showed higher nocturnal cortisol was both longitudinally and cross-sectionally associated with MDD in adolescence.
CONCLUSION
Our findings suggest elevated morning cortisol precedes depression in adolescence. Despite this, we did not find any differences in other cortisol measures in association with MDD in cross-sectional studies. Taken together, these findings suggest that elevated morning and nocturnal cortisol are risk factors for depression in adolescence rather than a biomarker of existing MDD. This supports a role for the hyperactivity of the HPA axis in the development of MDD in adolescence. Most of the studies were from high-income-countries (HICs) and thus further work would need to be conducted in low- and middle-income countries (LMICs) to understand if our findings are generalisable also to these populations.
Topics: Adolescent; Adult; Child; Cross-Sectional Studies; Depression; Depressive Disorder, Major; Humans; Hydrocortisone; Hypothalamo-Hypophyseal System; Pituitary-Adrenal System; Young Adult
PubMed: 34920399
DOI: 10.1016/j.psyneuen.2021.105625 -
Epilepsia Mar 2022Deep brain stimulation (DBS) is a neuromodulatory treatment used in patients with drug-resistant epilepsy (DRE). The primary goal of this systematic review and... (Meta-Analysis)
Meta-Analysis Review
Deep brain stimulation (DBS) is a neuromodulatory treatment used in patients with drug-resistant epilepsy (DRE). The primary goal of this systematic review and meta-analysis is to describe recent advancements in the field of DBS for epilepsy, to compare the results of published trials, and to clarify the clinical utility of DBS in DRE. A systematic literature search was performed by two independent authors. Forty-four articles were included in the meta-analysis (23 for anterior thalamic nucleus [ANT], 8 for centromedian thalamic nucleus [CMT], and 13 for hippocampus) with a total of 527 patients. The mean seizure reduction after stimulation of the ANT, CMT, and hippocampus in our meta-analysis was 60.8%, 73.4%, and 67.8%, respectively. DBS is an effective and safe therapy in patients with DRE. Based on the results of randomized controlled trials and larger clinical series, the best evidence exists for DBS of the anterior thalamic nucleus. Further randomized trials are required to clarify the role of CMT and hippocampal stimulation. Our analysis suggests more efficient deep brain stimulation of ANT for focal seizures, wider use of CMT for generalized seizures, and hippocampal DBS for temporal lobe seizures. Factors associated with clinical outcome after DBS for epilepsy are electrode location, stimulation parameters, type of epilepsy, and longer time of stimulation. Recent advancements in anatomical targeting, functional neuroimaging, responsive neurostimulation, and sensing of local field potentials could potentially lead to improved outcomes after DBS for epilepsy and reduced sudden, unexpected death of patients with epilepsy. Biomarkers are needed for successful patient selection, targeting of electrodes and optimization of stimulation parameters.
Topics: Anterior Thalamic Nuclei; Death, Sudden; Deep Brain Stimulation; Drug Resistant Epilepsy; Epilepsy; Hippocampus; Humans; Intralaminar Thalamic Nuclei; Seizures
PubMed: 34981509
DOI: 10.1111/epi.17157 -
Neuropsychology Review Jun 2023Deep brain stimulation (DBS) of the subthalamic nucleus (STN) or globus pallidum internus (GPi) improves motor functions in patients with Parkinson's disease (PD) but... (Meta-Analysis)
Meta-Analysis Review
Deep brain stimulation (DBS) of the subthalamic nucleus (STN) or globus pallidum internus (GPi) improves motor functions in patients with Parkinson's disease (PD) but may cause a decline in specific cognitive domains. The aim of this systematic review and meta-analysis was to assess the long-term (1-3 years) effects of STN or GPi DBS on four cognitive functions: (i) memory (delayed recall, working memory, immediate recall), (ii) executive functions including inhibition control (Color-Word Stroop test) and flexibility (phonemic verbal fluency), (iii) language (semantic verbal fluency), and (iv) mood (anxiety and depression). Medline and Web of Science were searched, and studies published before July 2021 investigating long-term changes in PD patients following DBS were included. Random-effects model meta-analyses were performed using the R software to estimate the standardized mean difference (SMD) computed as Hedges' g with 95% CI. 2522 publications were identified, 48 of which satisfied the inclusion criteria. Fourteen meta-analyses were performed including 2039 adults with a clinical diagnosis of PD undergoing DBS surgery and 271 PD controls. Our findings add new information to the existing literature by demonstrating that, at a long follow-up interval (1-3 years), both positive effects, such as a mild improvement in anxiety and depression (STN, Hedges' g = 0,34, p = 0,02), and negative effects, such as a decrease of long-term memory (Hedges' g = -0,40, p = 0,02), verbal fluency such as phonemic fluency (Hedges' g = -0,56, p < 0,0001), and specific subdomains of executive functions such as Color-Word Stroop test (Hedges' g = -0,45, p = 0,003) were observed. The level of evidence as qualified with GRADE varied from low for the pre- verses post-analysis to medium when compared to a control group.
Topics: Adult; Humans; Parkinson Disease; Deep Brain Stimulation; Subthalamic Nucleus; Globus Pallidus; Cognition; Neuropsychological Tests
PubMed: 35318587
DOI: 10.1007/s11065-022-09540-9 -
Journal of Psychiatry & Neuroscience :... Jan 2021Repetitive transcranial magnetic stimulation (rTMS) or transcranial direct current stimulation (tDCS) could provide treatment alternatives to stimulant medication for... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Repetitive transcranial magnetic stimulation (rTMS) or transcranial direct current stimulation (tDCS) could provide treatment alternatives to stimulant medication for attention-deficit/hyperactivity disorder (ADHD), given some evidence for improvements in cognition and clinical symptoms. However, despite a lack of solid evidence for their use, rTMS and tDCS are already offered clinically and commercially in ADHD. This systematic review and meta-analysis aimed to critically appraise rTMS and tDCS studies in ADHD to inform good research and clinical practice.
METHODS
A systematic search (up to February 2019) identified 18 studies (rTMS 4, tDCS 14; 311 children and adults with ADHD) stimulating mainly the dorsolateral prefrontal cortex (dlPFC). We included 12 anodal tDCS studies (232 children and adults with ADHD) in 3 random-effects meta-analyses of cognitive measures of attention, inhibition and processing speed.
RESULTS
The review of rTMS and tDCS showed positive effects in some functions but not others, and little evidence for clinical improvement. The meta-analyses of 1 to 5 sessions of anodal tDCS over mainly the left or bilateral dlPFC showed trend-level improvements in inhibition and processing speed, but not in attention.
LIMITATIONS
Heterogeneity in stimulation parameters, patient age and outcome measures limited the interpretation of findings.
CONCLUSION
The review and meta-analysis showed limited evidence that 1 to 5 sessions of rTMS and tDCS, mostly of the dlPFC, improved clinical or cognitive measures of ADHD. These findings did not support using rTMS or tDCS of the dlPFC as an alternative neurotherapy for ADHD as yet. Larger, multi-session stimulation studies identifying more optimal sites and stimulation parameters in combination with cognitive training could achieve larger effects.
Topics: Adolescent; Adult; Attention Deficit Disorder with Hyperactivity; Child; Humans; Outcome Assessment, Health Care; Prefrontal Cortex; Transcranial Direct Current Stimulation; Transcranial Magnetic Stimulation; Young Adult
PubMed: 33009906
DOI: 10.1503/jpn.190179 -
Journal of Affective Disorders Apr 2022Background We evaluated the efficacy and safety of repetitive transcranial magnetic stimulation (rTMS) for obsessive-compulsive disorder (OCD), and ranked the relative... (Meta-Analysis)
Meta-Analysis Review
Background We evaluated the efficacy and safety of repetitive transcranial magnetic stimulation (rTMS) for obsessive-compulsive disorder (OCD), and ranked the relative efficacy of different stimulation protocols. Methods We performed a search for randomised, sham-controlled trials of rTMS for OCD. The primary analysis included both a pairwise meta-analysis and a series of frequentist network meta-analyses (NMA) of OCD symptom severity. Secondary analyses were carried out on relevant clinical factors and safety. Results 21 studies involving 662 patients were included. The pairwise meta-analysis showed that rTMS for OCD is efficacious across all protocols (Hedges' g=-0.502 [95%CI= -0.708, -0.296]). The first NMA, with stimulation protocols clustered only by anatomical location, showed that both dorsolateral prefrontal cortex (dlPFC) stimulation and medial frontal cortex stimulation were efficacious. In the second NMA, considering each unique combination of frequency and location separately, low frequency (LF) pre-supplementary motor area (preSMA) stimulation, high frequency (HF) bilateral dlPFC stimulation, and LF right dlPFC stimulation were all efficacious . LF right dlPFC was ranked highest in terms of efficacy, although the corresponding confidence intervals overlapped with the other two protocols. Limitations Evidence base included mostly small studies, with only a few studies using similar protocols, giving a sparse network. Studies were heterogeneous, and a risk of publication bias was found. Conclusions rTMS for OCD was efficacious compared with sham stimulation. LF right dlPFC, HF bilateral dlPFC and LF preSMA stimulation were all efficacious protocols with significant and comparable clinical improvements. Future studies should further investigate the relative merits of these three protocols.
Topics: Humans; Motor Cortex; Network Meta-Analysis; Obsessive-Compulsive Disorder; Prefrontal Cortex; Transcranial Magnetic Stimulation; Treatment Outcome
PubMed: 35041869
DOI: 10.1016/j.jad.2022.01.048 -
The Lancet. Psychiatry Apr 2023The left dorsolateral prefrontal cortex is a prime target for repetitive transcranial magnetic stimulation (TMS) to treat neuropsychiatric disorders; thus, abundant... (Meta-Analysis)
Meta-Analysis
Effects of repetitive transcranial magnetic stimulation of the left dorsolateral prefrontal cortex on symptom domains in neuropsychiatric disorders: a systematic review and cross-diagnostic meta-analysis.
BACKGROUND
The left dorsolateral prefrontal cortex is a prime target for repetitive transcranial magnetic stimulation (TMS) to treat neuropsychiatric disorders; thus, abundant efficacy data from controlled trials are available. A cross-diagnostic meta-analysis was conducted to identify the symptom domains susceptible to repetitive TMS to the left dorsolateral prefrontal cortex.
METHODS
This systematic review and meta-analysis investigated the effects of repetitive TMS to the left dorsolateral prefrontal cortex on neuropsychiatric symptoms presenting across diagnoses. We searched PubMed, MEDLINE, Embase, Web of Science, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, and WHO International Clinical Trials Registry Platform for randomised and sham controlled trials published from inception to Aug 17, 2022. Included studies assessed symptoms using clinical measures and reported sufficient data to calculate effect sizes pooled with a random effects model. Two independent reviewers conducted screening and used the Cochrane risk-of-bias tool for quality assessment. Summary data were extracted from published reports. The main outcome was the therapeutic effects of repetitive TMS of the left dorsolateral prefrontal cortex on distinct symptom domains. This study is registered with PROSPERO (CRD42021278458).
FINDINGS
Of 9056 studies identified (6704 from databases and 2352 from registers), 174 were included in the analysis including 7905 patients. 163 of 174 studies reported gender data; 3908 (52·35%) of 7465 patients were male individuals, and 3557 (47·65%) were female individuals. Mean age was 44·63 years (range 19·79-72·80). Ethnicity data were mostly not available. Effect size was large for craving (Hedges'g -0·803 [95% CI -1·099 to -0·507], p<0·0001; I=82·40%), medium for depressive symptoms (-0·725 [-0·889 to -0·561], p<0·0001; I=85·66%), small for anxiety, obsessions or compulsions, pain, global cognition, declarative memory, working memory, cognitive control, and motor coordination (Hedges'g -0·198 to -0·491), and non-significant for attention, suicidal ideation, language, walking ability, fatigue, and sleep.
INTERPRETATION
The cross-diagnostic meta-analysis shows the efficacy of repetitive TMS of the left dorsolateral prefrontal cortex on distinct symptom domains, providing a novel framework for assessing target or efficacy interactions of repetitive TMS, and informing personalised applications for conditions for which regular trials are uninformative.
FUNDING
The University Grants Committee of Hong Kong and the Mental Health Research Center, The Hong Kong Polytechnic University.
Topics: Humans; Male; Female; Young Adult; Adult; Middle Aged; Aged; Transcranial Magnetic Stimulation; Dorsolateral Prefrontal Cortex; Pain; Anxiety Disorders; Cognition
PubMed: 36898403
DOI: 10.1016/S2215-0366(23)00026-3 -
Journal of Neuroengineering and... Feb 2022Transcranial magnetic stimulation (TMS) has attracted plenty of attention as it has been proved to be effective in facilitating motor recovery in patients with stroke.... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Transcranial magnetic stimulation (TMS) has attracted plenty of attention as it has been proved to be effective in facilitating motor recovery in patients with stroke. The aim of this study was to systematically review the effects of repetitive TMS (rTMS) and theta burst stimulation (TBS) protocols in modulating cortical excitability after stroke.
METHODS
A literature search was carried out using PubMed, Medline, EMBASE, CINAHL, and PEDro, to identify studies that investigated the effects of four rTMS protocols-low and high frequency rTMS, intermittent and continuous TBS, on TMS measures of cortical excitability in stroke. A random-effects model was used for all meta-analyses.
RESULTS
Sixty-one studies were included in the current review. Low frequency rTMS was effective in decreasing individuals' resting motor threshold and increasing the motor-evoked potential of the non-stimulated M1 (affected M1), while opposite effects occurred in the stimulated M1 (unaffected M1). High frequency rTMS enhanced the cortical excitability of the affected M1 alone. Intermittent TBS also showed superior effects in rebalancing bilateral excitability through increasing and decreasing excitability within the affected and unaffected M1, respectively. Due to the limited number of studies found, the effects of continuous TBS remained inconclusive. Motor impairment was significantly correlated with various forms of TMS measures.
CONCLUSIONS
Except for continuous TBS, it is evident that these protocols are effective in modulating cortical excitability in stroke. Current evidence does support the effects of inhibitory stimulation in enhancing the cortical excitability of the affected M1.
Topics: Cortical Excitability; Evoked Potentials, Motor; Humans; Motor Cortex; Stroke; Transcranial Magnetic Stimulation
PubMed: 35193624
DOI: 10.1186/s12984-022-00999-4 -
Psychological Medicine Apr 2020People with attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) have abnormalities in frontal, temporal, parietal and striato-thalamic... (Comparative Study)
Comparative Study Meta-Analysis
Comparative meta-analyses of brain structural and functional abnormalities during cognitive control in attention-deficit/hyperactivity disorder and autism spectrum disorder.
BACKGROUND
People with attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) have abnormalities in frontal, temporal, parietal and striato-thalamic networks. It is unclear to what extent these abnormalities are distinctive or shared. This comparative meta-analysis aimed to identify the most consistent disorder-differentiating and shared structural and functional abnormalities.
METHODS
Systematic literature search was conducted for whole-brain voxel-based morphometry (VBM) and functional magnetic resonance imaging (fMRI) studies of cognitive control comparing people with ASD or ADHD with typically developing controls. Regional gray matter volume (GMV) and fMRI abnormalities during cognitive control were compared in the overall sample and in age-, sex- and IQ-matched subgroups with seed-based d mapping meta-analytic methods.
RESULTS
Eighty-six independent VBM (1533 ADHD and 1295 controls; 1445 ASD and 1477 controls) and 60 fMRI datasets (1001 ADHD and 1004 controls; 335 ASD and 353 controls) were identified. The VBM meta-analyses revealed ADHD-differentiating decreased ventromedial orbitofrontal (z = 2.22, p < 0.0001) but ASD-differentiating increased bilateral temporal and right dorsolateral prefrontal GMV (zs ⩾ 1.64, ps ⩽ 0.002). The fMRI meta-analyses of cognitive control revealed ASD-differentiating medial prefrontal underactivation but overactivation in bilateral ventrolateral prefrontal cortices and precuneus (zs ⩾ 1.04, ps ⩽ 0.003). During motor response inhibition specifically, ADHD relative to ASD showed right inferior fronto-striatal underactivation (zs ⩾ 1.14, ps ⩽ 0.003) but shared right anterior insula underactivation.
CONCLUSIONS
People with ADHD and ASD have mostly distinct structural abnormalities, with enlarged fronto-temporal GMV in ASD and reduced orbitofrontal GMV in ADHD; and mostly distinct functional abnormalities, which were more pronounced in ASD.
Topics: Adolescent; Adult; Attention Deficit Disorder with Hyperactivity; Autism Spectrum Disorder; Brain; Cerebral Cortex; Child; Cognition; Female; Gray Matter; Humans; Magnetic Resonance Imaging; Male; Parietal Lobe; Thalamus; Young Adult
PubMed: 32216846
DOI: 10.1017/S0033291720000574 -
PloS One 2023Binaural beats are an auditory phenomenon that occurs when two tones of different frequencies, which are presented separately to each ear, elicit the sensation of a...
Binaural beats to entrain the brain? A systematic review of the effects of binaural beat stimulation on brain oscillatory activity, and the implications for psychological research and intervention.
Binaural beats are an auditory phenomenon that occurs when two tones of different frequencies, which are presented separately to each ear, elicit the sensation of a third tone oscillating at the difference frequency of the two tones. Binaural beats can be perceived in the frequency range of about 1-30 Hz, a range that coincides with the main human EEG frequency bands. The brainwave entrainment hypothesis, which assumes that external stimulation at a certain frequency leads to the brain's electrocortical activity oscillating at the same frequency, provides the basis for research on the effects of binaural beat stimulation on cognitive and affective states. Studies, particularly in more applied fields, usually refer to neuroscientific research demonstrating that binaural beats elicit systematic changes in EEG parameters. At first glance, however, the available literature on brainwave entrainment effects due to binaural beat stimulation appears to be inconclusive at best. The aim of the present systematic review is, thus, to synthesize existing empirical research. A sample of fourteen published studies met our criteria for inclusion. The results corroborate the impression of an overall inconsistency of empirical outcomes, with five studies reporting results in line with the brainwave entrainment hypothesis, eight studies reporting contradictory, and one mixed results. What is to be noticed is that the fourteen studies included in this review were very heterogeneous regarding the implementation of the binaural beats, the experimental designs, and the EEG parameters and analyses. The methodological heterogeneity in this field of study ultimately limits the comparability of research outcomes. The results of the present systematic review emphasize the need for standardization in study approaches so as to allow for reliable insight into brainwave entrainment effects in the future.
Topics: Humans; Acoustic Stimulation; Brain; Auditory Cortex; Brain Waves
PubMed: 37205669
DOI: 10.1371/journal.pone.0286023 -
Neurosurgical Focus Feb 2023Despite its relatively low prevalence, schizophrenia has a high burden of illness due to its lifelong effects and the fact that it is often refractory to psychotropic...
OBJECTIVE
Despite its relatively low prevalence, schizophrenia has a high burden of illness due to its lifelong effects and the fact that it is often refractory to psychotropic treatment. This review investigated how neurosurgical interventions, primarily neuromodulation through deep brain stimulation (DBS), can mitigate treatment-refractory schizophrenia. Pathophysiological data and ongoing clinical trials were reviewed to suggest which targets hold promise for neurosurgical efficacy.
METHODS
A systematic review of the literature was conducted via an electronic search of the PubMed, Scopus, and Web of Science databases. Included papers were human or animal studies of neurosurgical interventions for schizophrenia conducted between 2012 and 2022. An electronic search of ClinicalTrials.gov and the International Clinical Trials Registry Platform was conducted to find ongoing clinical trials. The ROBINS-I (Risk of Bias in Nonrandomized Studies of Interventions) assessment tool was used to evaluate risk of bias in the study.
RESULTS
Eight human and 2 rat studies were included in the review. Of the human studies, 5 used DBS targeting the nucleus accumbens, subgenual anterior cingulate cortex, habenula, and substantial nigra pars reticulata. The remaining 3 human studies reported the results of subcaudate tractotomies and anterior capsulotomies. The rat studies investigated DBS of the nucleus accumbens and medial prefrontal cortex. Overall, human studies demonstrated long-term reduction in Positive and Negative Syndrome Scale scores in many participants, with a low incidence of surgical and psychological side effects. The rat studies demonstrated improved prepulse and latent inhibition in the targeted areas after DBS.
CONCLUSIONS
As identified in this review, recent studies have investigated the potential effects of therapeutic DBS for schizophrenia, with varying results. DBS targets that have been explored include the hippocampus, subgenual anterior cingulate cortex, habenula, substantia nigra pars reticulata, and medial prefrontal cortex. In addition to DBS, other neuromodulatory techniques such as neuroablation have been studied. Current evidence suggests that neuroablation in the subcaudate tract and anterior capsulotomy may be beneficial for some patients. The authors recommend further exploration of neuromodulation for treatment-refractory schizophrenia, under the condition that rigorous standards be upheld when considering surgical candidacy for these treatments, given that their safety and efficacy remain to be determined.
Topics: Humans; Rats; Animals; Schizophrenia; Neurosurgery; Neurosurgical Procedures; Psychosurgery; Nucleus Accumbens; Deep Brain Stimulation
PubMed: 36724524
DOI: 10.3171/2022.11.FOCUS22620