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1.
Psychophysiology ; : e14556, 2024 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-38459778

RESUMO

Transcranial direct current stimulation (tDCS) of the prefrontal cortex (PFC) modulates the autonomic nervous system by activating deeper brain areas via top-down pathway. However, effects on the nervous system are heterogeneous and may depend on the amount of current that penetrates. Therefore, we aimed to investigate the variable effects of tDCS on heart rate variability (HRV), a measure of the functional state of the autonomic nervous system. Using three prefrontal tDCS protocols (1.5, 3 mA and sham), we associated the simulated individual electric field (E-field) magnitude in brain regions of interest with the HRV effects. This was a randomized, double-blinded, sham-controlled and within-subject trial, in which healthy young-adult participants received tDCS sessions separated by 2 weeks. The brain regions of interest were the dorsolateral PFC (DLPFC), anterior cingulate cortex, insula and amygdala. Overall, 37 participants were investigated, corresponding to a total of 111 tDCS sessions. The findings suggested that HRV, measured by root mean squared of successive differences (RMSSD) and high-frequency HRV (HF-HRV), were significantly increased by the 3.0 mA tDCS when compared to sham and 1.5 mA. No difference was found between sham and 1.5 mA. E-field analysis showed that all brain regions of interest were associated with the HRV outcomes. However, this significance was associated with the protocol intensity, rather than inter-individual brain structural variability. To conclude, our results suggest a dose-dependent effect of tDCS for HRV. Therefore, further research is warranted to investigate the optimal current dose to modulate HRV.

2.
Neurosci Biobehav Rev ; 158: 105570, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38311046

RESUMO

This systematic review and a meta-analysis synthesised the results from contemporary, randomized and non-randomized controlled studies to assess lasting (one week minimum) changes on cognition/creativity, emotional processing and personality from serotonergic psychedelics. PubMed, Embase and PsycInfo were searched in July 2022. Risk of bias was assessed using Rob 2.0 and ROBINS-I. Ten studies met the eligibility criteria which involved 304 participants. No statistically significant effects were found for the majority outcome measures across the three constructs. A meta-analysis of emotional recognition outcomes found an overall significant effect for faster reaction times in the active treatment groups for disgust (SMD=-0.63, 95% CI=[-1.01 to -0.25], I2 = 65%) and sadness (SMD=-0.45, 95% CI=[-0.85 to -0.06], I2 = 60%). Future research should include larger samples, better control conditions, standardized doses and longer follow-up periods to confirm these preliminary findings.


Assuntos
Alucinógenos , Humanos , Cognição , Personalidade , Emoções
3.
Brain Sci ; 13(12)2023 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-38137113

RESUMO

(1) Background: Psychological interventions are effective in alleviating neuropsychiatric symptoms, though results can vary between patients. Repetitive transcranial magnetic stimulation (rTMS) has been proven to improve clinical symptoms and cognition. It remains unclear whether rTMS can augment the efficacy of psychological interventions. (2) Methods: We examined the effects of rTMS combined with psychological interventions on clinical, functional, and cognitive outcomes from randomized controlled trials conducted in healthy and clinical populations. We searched PubMed, EMBASE, Cochrane Library, and PsycINFO databases up to April 2023. (3) Results: Twenty-seven studies were ultimately included. Compared to sham rTMS combined with psychological interventions, active rTMS combined with psychological interventions significantly improved overall clinical symptoms (k = 16, SMD = 0.31, CIs 0.08 to 0.54, p < 0.01). We found that 10 or more sessions of rTMS combined with cognitive behavioural therapy significantly improved clinical outcomes overall (k = 3, SMD = 0.21, CIs 0.05 to 0.36, Z = 2.49, p < 0.01). RTMS combined with cognitive training (CT) significantly improved cognition overall compared to sham rTMS combined with CT (k = 13, SMD = 0.28, CIs 0.15 to 0.42, p < 0.01), with a significant effect on global cognition (k = 11, SMD = 0.45, CIs 0.21 to 0.68, p < 0.01), but not on the other cognitive domains. (4) Conclusion: The current results provide preliminary support for the augmentation effects of active rTMS on clinical and cognitive outcomes across diverse populations. Future clinical trials are required to confirm these augmentation effects for specific psychological interventions in specific clinical populations.

4.
Br J Psychiatry ; 223(6): 533-541, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-38108319

RESUMO

BACKGROUND: Prior trials suggest that intravenous racemic ketamine is a highly effective for treatment-resistant depression (TRD), but phase 3 trials of racemic ketamine are needed. AIMS: To assess the acute efficacy and safety of a 4-week course of subcutaneous racemic ketamine in participants with TRD. Trial registration: ACTRN12616001096448 at www.anzctr.org.au. METHOD: This phase 3, double-blind, randomised, active-controlled multicentre trial was conducted at seven mood disorders centres in Australia and New Zealand. Participants received twice-weekly subcutaneous racemic ketamine or midazolam for 4 weeks. Initially, the trial tested fixed-dose ketamine 0.5 mg/kg versus midazolam 0.025 mg/kg (cohort 1). Dosing was revised, after a Data Safety Monitoring Board recommendation, to flexible-dose ketamine 0.5-0.9 mg/kg or midazolam 0.025-0.045 mg/kg, with response-guided dosing increments (cohort 2). The primary outcome was remission (Montgomery-Åsberg Rating Scale for Depression score ≤10) at the end of week 4. RESULTS: The final analysis (those who received at least one treatment) comprised 68 in cohort 1 (fixed-dose), 106 in cohort 2 (flexible-dose). Ketamine was more efficacious than midazolam in cohort 2 (remission rate 19.6% v. 2.0%; OR = 12.1, 95% CI 2.1-69.2, P = 0.005), but not different in cohort 1 (remission rate 6.3% v. 8.8%; OR = 1.3, 95% CI 0.2-8.2, P = 0.76). Ketamine was well tolerated. Acute adverse effects (psychotomimetic, blood pressure increases) resolved within 2 h. CONCLUSIONS: Adequately dosed subcutaneous racemic ketamine was efficacious and safe in treating TRD over a 4-week treatment period. The subcutaneous route is practical and feasible.


Assuntos
Transtorno Depressivo Resistente a Tratamento , Ketamina , Humanos , Ketamina/efeitos adversos , Depressão , Midazolam/efeitos adversos , Austrália , Transtorno Depressivo Resistente a Tratamento/tratamento farmacológico
5.
EClinicalMedicine ; 62: 102127, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37593223

RESUMO

Background: Intranasal esketamine has received regulatory approvals for the treatment of depression. Recently a large trial of repeated dose racemic ketamine also demonstrated efficacy in severe depression. However, uncertainties remain regarding comparative efficacy, dosage, and the time course of response. Methods: In this systematic review and meta-analysis, we searched Embase, Medline, Pubmed, PsycINFO, and CENTRAL up to April 13, 2023, for randomised controlled trials (RCTs) investigating ketamine for depression. Two investigators independently assessed study eligibility and risk of bias and extracted the data on depression severity scores, response and remission rates, and all-cause dropouts. Multivariable mixed-effects meta-regressions incorporated drug formulation (racemic (Rac) or esketamine (Esket)) and dose (Low or High) as covariates. Treatment effects were assessed: immediately following the first dose, during further repeated dosing, and follow-up after the final dose of a treatment course. This study is registered with PROSPERO (CRD42021221157). Findings: The systematic review identified 687 articles, of which 49 RCTs were eligible for analysis, comprising 3299 participants. Standardised mean differences (95% confidence intervals) immediately following the first/single treatment were moderate-high for all conditions (Rac-High: -0.73, -0.91 to -0.56; Esket-High: -0.48, -0.75 to -0.20; Rac-Low: -0.33, -0.54 to -0.12; Esket-Low: -0.55, -0.87 to -0.24). Ongoing effects during repeated dosing were significantly greater than the control for Rac-High (-0.61; -1.02 to -0.20) and Rac-Low (-0.55, -1.09 to -0.00), but not Esket-Low (-0.15, -0.49 to 0.19) or Esket-High (-0.22, -0.54 to 0.10). At follow-up effects remained significant for racemic ketamine (-0.65; -1.23 to -0.07) but not esketamine (-0.33; -0.96 to 0.31). All-cause dropout was similar between experiment and control conditions for both formulations combined (Odds Ratio = 1.18, 0.85-1.64). Overall heterogeneity varied from 5.7% to 87.6. Interpretation: Our findings suggested that effect sizes for depression severity, as well as response and remission rates, were numerically greater for racemic ketamine than esketamine. Higher doses were more effective than low doses. Differences were evident in initial effects, ongoing treatment, and lasting effects after the final dose. Funding: None.

6.
Artigo em Inglês | MEDLINE | ID: mdl-36931456

RESUMO

INTRODUCTION: Prefrontal transcranial direct current stimulation (tDCS) shows promise as an effective treatment for depression. However, factors influencing treatment and the time-course of symptom improvements remain to be elucidated. METHODS: Individual participant data was collected from ten randomised controlled trials of tDCS in depression. Depressive symptom scores were converted to a common scale, and a linear mixed effects individual growth curve model was fit to the data using k-fold cross-validation to prevent overfitting. RESULTS: Data from 576 participants were analysed (tDCS: n = 311; sham: n = 265), of which 468 were unipolar and 108 had bipolar disorder. tDCS effect sizes reached a peak at approximately 6 weeks, and continued to diverge from sham up to 10 weeks. Significant predictors associated with worse response included higher baseline depression severity, treatment resistance, and those associated with better response included bipolar disorder and anxiety disorder. CONCLUSIONS: Our findings suggest that longer treatment courses, lasting at least 6 weeks in duration, may be indicated. Further, our results show that tDCS is effective for depressive symptoms in bipolar disorder. Compared to unipolar depression, participants with bipolar disorder may require additional maintenance sessions to prevent rapid relapse.


Assuntos
Transtorno Bipolar , Transtorno Depressivo Maior , Estimulação Transcraniana por Corrente Contínua , Humanos , Estimulação Transcraniana por Corrente Contínua/métodos , Transtorno Depressivo Maior/terapia , Transtorno Bipolar/terapia , Antidepressivos/uso terapêutico , Resultado do Tratamento , Método Duplo-Cego
7.
Neuropsychol Rev ; 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36857011

RESUMO

High-frequency repetitive transcranial magnetic stimulation (HF-rTMS) is a commonly used form of rTMS to treat neuropsychiatric disorders. Emerging evidence suggests that 'offline' HF-rTMS may have cognitive enhancing effects, although the magnitude and moderators of these effects remain unclear. We conducted a systematic review and meta-analysis to clarify the cognitive effects of offline HF-rTMS in healthy individuals. A literature search for randomised controlled trials with cognitive outcomes for pre and post offline HF-rTMS was performed across five databases up until March 2022. This study was registered on the PROSPERO international prospective protocol for systematic reviews (PROSPERO 2020 CRD 42,020,191,269). The Risk of Bias 2 tool was used to assess the risk of bias in randomised trials. Separate analyses examined the cognitive effects of excitatory and inhibitory forms of offline HF-rTMS on accuracy and reaction times across six cognitive domains. Fifty-three studies (N = 1507) met inclusion criteria. Excitatory offline HF-rTMS showed significant small sized effects for improving accuracy (k = 46, g = 0.12) and reaction time (k = 44, g = -0.13) across all cognitive domains collapsed. Excitatory offline HF-rTMS demonstrated a relatively greater effect for executive functioning in accuracy (k = 24, g = 0.14). Reaction times were also improved for the executive function (k = 21, g = -0.11) and motor (k = 3, g = -0.22) domains following excitatory offline HF-rTMS. The current review was restricted to healthy individuals and future research is required to examine cognitive enhancement from offline HF-rTMS in clinical cohorts.

8.
J Cogn Neurosci ; 35(3): 468-484, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36603051

RESUMO

The effects of transcranial direct current stimulation (tDCS) at the pFC are often investigated using cognitive paradigms, particularly working memory tasks. However, the neural basis for the neuromodulatory cognitive effects of tDCS, including which subprocesses are affected by stimulation, is not completely understood. We investigated the effects of tDCS on working memory task-related spectral activity during and after tDCS to gain better insights into the neurophysiological changes associated with stimulation. We reanalyzed data from 100 healthy participants grouped by allocation to receive either sham (0 mA, 0.016 mA, and 0.034 mA) or active (1 mA or 2 mA) stimulation during a 3-back task. EEG data were used to analyze event-related spectral power in frequency bands associated with working memory performance. Frontal theta event-related synchronization (ERS) was significantly reduced post-tDCS in the active group. Participants receiving active tDCS had slower RTs following tDCS compared with sham, suggesting interference with practice effects associated with task repetition. Theta ERS was not significantly correlated with RTs or accuracy. tDCS reduced frontal theta ERS poststimulation, suggesting a selective disruption to working memory cognitive control and maintenance processes. These findings suggest that tDCS selectively affects specific subprocesses during working memory, which may explain heterogenous behavioral effects.


Assuntos
Estimulação Transcraniana por Corrente Contínua , Humanos , Memória de Curto Prazo/fisiologia , Córtex Pré-Frontal/fisiologia , Cognição/fisiologia
9.
BMJ Open ; 12(12): e068313, 2022 12 22.
Artigo em Inglês | MEDLINE | ID: mdl-36549738

RESUMO

INTRODUCTION: There have been important advances in the use of electroconvulsive therapy (ECT) to treat major depressive episodes. These include variations to the type of stimulus the brain regions stimulated, and the stimulus parameters (eg, stimulus duration/pulse width). Our aim is to investigate ECT types using a network meta-analysis (NMA) approach and report on comparative treatment efficacy, cognitive side effects and acceptability. METHOD: We will conduct a systematic review to identify randomised controlled trials that compared two or more ECT protocols to treat depression. This will be done using the following databases: Embase, MEDLINE PubMed, Web of Science, Scopus, PsycINFO, Cochrane CENTRAL and will be supplemented by personal contacts with researchers in the field. All authors will be contacted to provide missing information. Primary outcomes will be symptom severity on a validated continuous clinician-rated scale of depression, cognitive functioning measured using anterograde verbal recall, and acceptability calculated using all-cause drop-outs. Secondary outcomes will include response and remission rates, autobiographical memory following a course of ECT, and anterograde visuospatial recall.Bayesian random effects hierarchical models will compare ECT types. Additional meta-regressions may be conducted to determine the impact of effect modifiers and patient-specific prognostic factors if sufficient data are available. DISCUSSION: This NMA will facilitate clinician decision making and allow more sophisticated selection of ECT type according to the balance of efficacy, cognitive side effects and acceptability. ETHICS: This systematic review and NMA does not require research ethics approval as it will use published aggregate data and will not collect nor disclose individually identifiable participant data. PROSPERO REGISTRATION NUMBER: CRD42022357098.


Assuntos
Transtorno Depressivo Maior , Eletroconvulsoterapia , Humanos , Eletroconvulsoterapia/efeitos adversos , Eletroconvulsoterapia/métodos , Transtorno Depressivo Maior/terapia , Depressão/terapia , Metanálise em Rede , Teorema de Bayes , Cognição , Revisões Sistemáticas como Assunto , Metanálise como Assunto
10.
Sci Data ; 9(1): 717, 2022 11 21.
Artigo em Inglês | MEDLINE | ID: mdl-36414684

RESUMO

Theta burst stimulation (TBS) is a new form of repetitive transcranial magnetic stimulation (TMS) capable of non-invasively modulating cortical excitability. In recent years TBS has been increasingly used as a neuroscientific investigative tool and therapeutic intervention for psychiatric disorders, in which the dorsolateral prefrontal cortex (DLPFC) is often the primary target. However, the neuromodulatory effects of TBS on prefrontal regions remain unclear. Here we share EEG and ECG recordings and structural MRI scans, including high-resolution DTI, from twenty-four healthy participants who received intermittent TBS (two sessions), continuous TBS (two sessions), and sham stimulation (one session) applied to the left DLPFC using a single-blinded crossover design. Each session includes eyes-open resting-state EEG and single-pulse TMS-EEG obtained before TBS and 2-, 15-, and 30-minutes post-stimulation. This dataset enables foundational basic science investigations into the neuromodulatory effects of TBS on the DLPFC.


Assuntos
Córtex Pré-Frontal , Estimulação Magnética Transcraniana , Humanos , Voluntários Saudáveis , Imageamento por Ressonância Magnética
11.
Exp Brain Res ; 240(1): 71-80, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34625838

RESUMO

Repetitive transcranial magnetic stimulation (rTMS) has the potential to be developed as a novel treatment for cognitive dysfunction. However, current methods of targeting rTMS for cognition fail to consider inter-individual functional variability. This study explored the use of a cognitive task to individualise the target site for rTMS administered to the left dorsolateral prefrontal cortex (L-DLPFC). Twenty-five healthy participants were enrolled in a sham-controlled, crossover study. Participants performed a random letter generation task under the following conditions: no stimulation, sham and active 'online' rTMS applied to F3 (International 10-20 System) and four standardised surrounding sites. Across all sites combined, active 'online' rTMS was associated with significantly reduced performance compared to sham rTMS for unique trigrams (p = 0.012), but not for unique digrams (p > 0.05). Using a novel localisation methodology based on performance outcomes from both measures, a single optimal individualised site was identified for 92% [n = 23] of participants. At the individualised site, performance was significantly poorer compared to a common standard site (F3) and both control conditions (ps < 0.01). The current results suggest that this localisation methodology using a cognitive task could be used to individualise the rTMS target site at the L-DLPFC for modulating and potentially enhancing cognitive functioning.


Assuntos
Córtex Pré-Frontal Dorsolateral , Estimulação Magnética Transcraniana , Cognição , Estudos Cross-Over , Humanos , Córtex Pré-Frontal
12.
J Affect Disord ; 295: 559-568, 2021 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-34509071

RESUMO

OBJECTIVE: Major depressive disorder (MDD) is associated with deficits in working memory. Several cognitive subprocesses interact to produce working memory, including attention, encoding, maintenance and manipulation. We sought to clarify the contribution of functional deficits in these subprocesses in MDD by varying cognitive load during a working memory task. METHODS: 41 depressed participants and 41 age and gender-matched healthy controls performed the n-back working memory task at three levels of difficulty (0-, 1-, and 2-back) in a pregistered study. We assessed response times, accuracy, and event-related electroencephalography (EEG), including P2 and P3 amplitudes, and frontal theta power (4-8 Hz). RESULTS: MDD participants had prolonged response times and more positive frontal P3 amplitudes (i.e., Fz) relative to controls, mainly in the most difficult 2-back condition. Working memory accuracy, P2 amplitudes and frontal theta event-related synchronisation did not differ between groups at any level of task difficulty. CONCLUSIONS: Depression is associated with generalized psychomotor slowing of working memory processes, and may involve compensatory hyperactivity in frontal and parietal regions. SIGNIFICANCE: These findings provide insights into MDD working memory deficits, indicating that depressed individuals dedicate greater levels of cortical processing and cognitive resources to achieve comparable working memory performance to controls.


Assuntos
Transtorno Depressivo Maior , Memória de Curto Prazo , Atenção , Eletroencefalografia , Humanos , Transtornos da Memória
13.
J Affect Disord ; 284: 1-8, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33581489

RESUMO

BACKGROUND: Depression is associated with cognitive deficits across multiple domains, including working memory. The n-back task, a convenient psychometric tool capable of computerised delivery and concurrent use with neuroimaging, can provide enhanced insight into working memory dysfunction in depression. This meta-analysis sought to investigate the n-back task under varying cognitive load conditions (i.e. different levels of 'n') to clarify the pattern of working memory deficits in depression. METHODS: We conducted a systematic review and meta-analysis of studies involving unipolar depressed participants and matched controls utilising the n-back task. Meta-analyses were performed for accuracy and response times at four levels of cognitive load (0-, 1-, 2-, and 3-back). RESULTS: 31 studies (total 1,666 participants) met inclusion criteria and were included for quantitative analyses. Depressed individuals had significantly reduced accuracy compared to controls for 1-, 2-, and 3-back tasks, but not the attentional 0-back task. Likewise, response latencies were prolonged for all task levels (0-, 1-, 2-, and 3-back). Additional meta-regression analyses indicated that participant age and clinical status (i.e. inpatient/outpatient) may exacerbate working memory deficits associated with depression. LIMITATIONS: Our results indicate high levels of heterogeneity between studies, particularly for response times. CONCLUSIONS: Accuracy impairments were worse at higher levels of n, with the largest effect size obtained on the 2-back task, suggesting deficits to higher executive functions. Response times were consistently prolonged at all cognitive loads in agreement with a pattern of generalised psychomotor retardation.


Assuntos
Transtornos Cognitivos , Memória de Curto Prazo , Depressão , Função Executiva , Humanos , Transtornos da Memória , Testes Neuropsicológicos
14.
Artigo em Inglês | MEDLINE | ID: mdl-33497753

RESUMO

BACKGROUND: Randomised clinical trials (RCTs) investigating transcranial direct current stimulation (tDCS) efficacy for depression show significant heterogeneity in outcomes. OBJECTIVE: To investigate the magnitude of the sham tDCS response and its potential moderators in the treatment of depression. METHODOLOGY: A systematic review and aggregate meta-analysis (PROSPERO ID CRD42020161254). The systematic review was conducted in the PubMed, Scopus (EMBASE) and Cochrane Library databases. Only RCTs enrolling adult subjects with an acute depressive episode with a sham tDCS group were included. RESULTS: Twenty-three studies (twenty-five datasets, 501 participants) were included. Sham tDCS response was large (Hedges' g = 1.09; 95% CI: 0.8;1.38). Secondary and subgroup analyses showed that sham protocols employing a ramp-up/ramp-down at the beginning and end of stimulation presented a significantly lower sham response compared to other protocols. Univariate meta-regression analyses found that sham response was associated with higher risk of blinding bias, and with thetreatment effect size of the active tDCS group. Subgroup analyses also showed that placement of the cathode over the lateral right frontal area (F8) presented a significantly lower sham response. Other moderators, including treatment resistance, baseline severity of depressive symptoms, and total charge delivered were not associated with the magnitude of the sham response. CONCLUSION: The sham tDCS response was large. Our findings demonstrate the need for standardization of sham tDCS protocols and bring attention to important considerations that can guide future RCTs employing tDCS for the treatment of MDD.


Assuntos
Transtorno Depressivo/terapia , Estimulação Transcraniana por Corrente Contínua , Humanos , Resultado do Tratamento
15.
Neuropsychology ; 34(6): 726-734, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32324004

RESUMO

BACKGROUND: Major depressive disorder (MDD) is commonly associated with neurocognitive dysfunction. However, there remains substantial heterogeneity between patients and inconsistent findings regarding the magnitude and prevalence of specific neurocognitive deficits. This study aimed to investigate the potential for different neurocognitive subgroups in patients diagnosed with MDD. METHOD: Data were pooled from 4 different clinical trials that involved adults diagnosed with MDD. Neurocognitive outcomes included measures of verbal learning and memory, executive function, attention, and processing speed. Latent class analysis was conducted to examine for different subgroups based on neurocognitive profiles of performance across outcome measures. Subgroups were compared to a separate sample of age-matched adult healthy controls, across illness factors, and individual mood items on the Montgomery-Åsberg Depression Rating Scale (MADRS). RESULTS: Within the MDD cohort (N = 149), 45% of participants were considered relatively "cognitively preserved," with the remainder "cognitively reduced" (39%) or "cognitively impaired" (16%). Verbal memory performance was significantly poorer compared to attention and processing speed only in the "cognitively impaired" subgroup. There was no association between subgroup membership and relevant illness factors, including ratings on individual MADRS items. LIMITATIONS: Data were pooled from several studies that included different neurocognitive measures and cohorts. CONCLUSIONS: Approximately half of MDD participants had no or minimal objective cognitive difficulties, and neurocognitive functioning was found generally unrelated to illness factors. Future longitudinal research is warranted to determine whether the people who are relatively cognitively impaired are at increased risk for further cognitive decline. (PsycInfo Database Record (c) 2020 APA, all rights reserved).


Assuntos
Transtornos Cognitivos/classificação , Transtornos Cognitivos/psicologia , Transtorno Depressivo Maior/classificação , Transtorno Depressivo Maior/psicologia , Adulto , Idoso , Atenção , Transtornos Cognitivos/etiologia , Transtorno Depressivo Maior/complicações , Manual Diagnóstico e Estatístico de Transtornos Mentais , Método Duplo-Cego , Função Executiva , Feminino , Humanos , Masculino , Memória , Pessoa de Meia-Idade , Testes Neuropsicológicos , Escalas de Graduação Psiquiátrica , Tempo de Reação , Aprendizagem Verbal
16.
Brain Stimul ; 13(2): 450-456, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31889671

RESUMO

BACKGROUND: The anaesthetic approach adopted in ECT practice has the potential to influence patient outcomes. However, the impact of the time interval between anaesthetic induction and ECT stimulus administration has not been studied prospectively to date. This variable may represent an indirect measure of anaesthetic concentration at the time of stimulation, and therefore may influence the quality of seizures induced. OBJECTIVE: To examine the impact of the anaesthetic to ECT stimulus time interval, and ventilation rate pre-treatment, on ictal seizure quality. METHODS: In a prospective, crossover trial, 54 depressed participants were randomised to variations in anaesthetic technique at four sequential ECT treatment sessions, in a 2 x 2 design: randomisation to a short or long anaesthetic-ECT time interval, and randomisation to normal ventilation or hyperventilation during anaesthetic induction with thiopentone. Ictal EEG data were collected at each study session and assessed by a blinded rater for ictal quality (seizure amplitude, regularity, post-ictal suppression and general seizure quality), using a quantitative-qualitative structured rating scale. Linear mixed effects models were used to analyse the effect of the anaesthetic-ECT time interval, and that of ventilation rate, on seizure quality indices. RESULTS: The anaesthetic-ECT time interval had a significant impact on ictal EEG quality indices (p < 0.01), with longer time intervals producing higher quality seizures. Ventilation rate did not significantly influence quality measures. CONCLUSION: The time between anaesthetic induction and ECT stimulus administration has a significant impact on ictal EEG seizure quality. Conversely, manipulations of ventilation rate did not significantly affect seizure quality. These results suggest the anaesthetic-ECT time interval should be routinely monitored clinically and potentially optimised for maximising seizure quality with ECT.


Assuntos
Depressão/terapia , Eletroconvulsoterapia/métodos , Convulsões/fisiopatologia , Adulto , Anestesia Intravenosa/métodos , Ondas Encefálicas , Eletroconvulsoterapia/efeitos adversos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Taxa Respiratória
17.
Int J Neuropsychopharmacol ; 23(3): 146-156, 2020 04 21.
Artigo em Inglês | MEDLINE | ID: mdl-31899509

RESUMO

BACKGROUND: Transcranial electrical stimulation has broad potential as a treatment for depression. Transcranial random noise stimulation, which delivers randomly fluctuating current intensities, may have greater cortical excitatory effects compared with other forms of transcranial electrical stimulation. We therefore aimed to investigate the antidepressant efficacy of transcranial random noise stimulation. METHODS: Depressed participants were randomly assigned by computer number generator to receive 20 sessions of either active or sham transcranial random noise stimulation over 4 weeks in a double-blinded, parallel group randomized-controlled trial. Transcranial random noise stimulation was delivered for 30 minutes with a direct current offset of 2 mA and a random noise range of 2 mA. Primary analyses assessed changes in depression severity using the Montgomery-Asperg Depression Rating Scale. Neuroplasticity, neuropsychological, and safety outcomes were analyzed as secondary measures. RESULTS: Sixty-nine participants were randomized, of which 3 discontinued treatment early, leaving 66 (sham n = 34, active n = 32) for per-protocol analysis. Depression severity scores reduced in both groups (Montgomery-Asperg Depression Rating Scale reduction in sham = 7.0 [95% CI = 5.0-8.9]; and active = 5.2 [95% CI = 3.2-7.3]). However, there were no differences between active and sham groups in the reduction of depressive symptoms or the number of participants meeting response (sham = 14.7%; active = 3.1%) and remission criteria (sham = 5.9%; active = 0%). Erythema, paresthesia, fatigue, and dizziness/light-headedness occurred more frequently in the active transcranial random noise stimulation group. Neuroplasticity, neuropsychological, and acute cognitive effects were comparable between groups. CONCLUSION: Our results do not support the use of transcranial random noise stimulation with the current stimulation parameters as a therapeutic intervention for the treatment of depression. CLINICAL TRIAL REGISTRATION AT CLINICALTRIALS: gov/NCT01792414.


Assuntos
Transtorno Bipolar/terapia , Depressão/terapia , Transtorno Depressivo Maior/terapia , Estimulação Transcraniana por Corrente Contínua , Adulto , Transtorno Bipolar/complicações , Disfunção Cognitiva/etiologia , Disfunção Cognitiva/terapia , Depressão/complicações , Transtorno Depressivo Maior/complicações , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Plasticidade Neuronal/fisiologia , Placebos , Índice de Gravidade de Doença , Estimulação Transcraniana por Corrente Contínua/efeitos adversos , Estimulação Transcraniana por Corrente Contínua/métodos , Falha de Tratamento
18.
Eur J Neurosci ; 51(10): 2119-2133, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31859397

RESUMO

Transcranial direct current stimulation (tDCS), a form of non-invasive brain stimulation, is a promising treatment for depression. Recent research suggests that tDCS efficacy can be augmented using concurrent cognitive-emotional training (CET). However, the neurophysiological changes associated with this combined intervention remain to be elucidated. We therefore examined the effects of tDCS combined with CET using electroencephalography (EEG). A total of 20 participants with treatment-resistant depression took part in this open-label study and received 18 sessions over 6 weeks of tDCS and concurrent CET. Resting-state and task-related EEG during a 3-back working memory task were acquired at baseline and immediately following the treatment course. Results showed an improvement in mood and working memory accuracy, but not response time, following the intervention. We did not find significant effects of the intervention on resting-state power spectral density (frontal theta and alpha asymmetry), time-frequency power (alpha event-related desynchronisation and theta event-related synchronisation) or event-related potentials (P2 and P3 components). We therefore identified little evidence of neurophysiological changes associated with treatment using tDCS and concurrent CET, despite significant improvements in mood and near-transfer effects of cognitive training to working memory accuracy. Further research incorporating a sham-controlled group may be necessary to identify the neurophysiological effects of the intervention.


Assuntos
Estimulação Transcraniana por Corrente Contínua , Cognição , Depressão , Humanos , Memória de Curto Prazo , Córtex Pré-Frontal
19.
J Int Neuropsychol Soc ; 25(9): 972-984, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31397255

RESUMO

OBJECTIVES: Noninvasive brain stimulation methods, including high-definition transcranial direct current stimulation (HD-tDCS) and theta burst stimulation (TBS) have emerged as novel tools to modulate and explore brain function. However, the relative efficacy of these newer stimulation approaches for modulating cognitive functioning remains unclear. This study investigated the cognitive effects of HD-tDCS, intermittent TBS (iTBS) and prolonged continuous TBS (ProcTBS) and explored the potential of these approaches for modulating hypothesized functions of the left posterior parietal cortex (PPC). METHODS: Twenty-two healthy volunteers attended four experimental sessions in a cross-over experimental design. In each session, participants either received HD-tDCS, iTBS, ProcTBS or sham, and completed cognitive tasks, including a divided attention task, a working memory maintenance task and an attention task (emotional Stroop test). RESULTS: The results showed that compared to sham, HD-tDCS, iTBS and ProcTBS caused significantly faster response times on the emotional Stroop task. The effect size (Cohen's d) was d = .32 for iTBS (p < .001), .21 for ProcTBS (p = .01) and .15 for HD-tDCS (p = .044). However, for the performance on the divided attention and working memory maintenance tasks, no significant effect of stimulation was found. CONCLUSIONS: The results suggest that repetitive transcranial magnetic stimulation techniques, including TBS, may have greater efficacy for modulating cognition compared with HD-tDCS, and extend existing knowledge about specific functions of the left PPC.


Assuntos
Atenção/fisiologia , Função Executiva/fisiologia , Memória de Curto Prazo/fisiologia , Lobo Parietal/fisiologia , Estimulação Transcraniana por Corrente Contínua/métodos , Estimulação Magnética Transcraniana/métodos , Adulto , Estudos Cross-Over , Feminino , Humanos , Masculino , Adulto Jovem
20.
J Affect Disord ; 252: 135-140, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-30981950

RESUMO

BACKGROUND: The time between anaesthetic induction and ECT stimulus administration has been hypothesised to significantly impact ictal EEG quality. In this study, our aim was to examine the effect of the time interval between anaesthetic induction and the ECT stimulus for ictal seizure quality in ECT sessions utilising thiopentone anaesthesia. METHODS: 413 EEG traces from 42 patients, collected retrospectively, were manually rated using a quantitative-qualitative structured rating scale (indices including seizure amplitude, regularity, post-ictal suppression and general seizure quality). Linear Mixed Effects Models were used to analyse the effect of the anaesthetic-ECT time interval on seizure quality indices, seizure duration and orientation scores after ECT, controlling for patient and ECT treatment factors. RESULTS: The anaesthetic-ECT time interval had a significant impact on ictal EEG quality indices (p < 0.05), with longer times producing higher quality seizures. Seizure duration and orientation scores after ECT were not significantly influenced by the anaesthetic-ECT time interval. Age, anaesthetic dose, ECT type and ECT treatment number also had a significant impact on measures of seizure quality (p < 0.05). LIMITATIONS: The effect of ventilation technique was not explicitly measured. Only manual ratings of ictal quality were analysed. CONCLUSIONS: The time between anaesthetic induction and ECT stimulus administration has a significant impact on the ictal EEG seizure quality observed, with thiopentone anaesthetic. These results are consistent with prior findings with propofol anaesthesia, and suggest a need for routine clinical monitoring of this time interval. This variable warrants consideration when interpreting ictal EEGs, which often informs subsequent dosing decisions.


Assuntos
Eletroconvulsoterapia/métodos , Convulsões/induzido quimicamente , Convulsões/fisiopatologia , Tiopental/farmacologia , Adolescente , Adulto , Anestésicos Intravenosos/administração & dosagem , Anestésicos Intravenosos/farmacologia , Eletroencefalografia/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Tempo , Adulto Jovem
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