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1.
Mol Psychiatry ; 2024 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-38503927

RESUMEN

Some data suggest that antipsychotics may adversely affect brain structure. We examined the relationship among olanzapine exposure, relapse, and changes in brain structure in patients with major depressive disorder with psychotic features. We analyzed data from the Study of the Pharmacotherapy of Psychotic Depression II trial (STOP-PD II), a randomized, placebo-controlled trial in patients with psychotic depression who attained remission on sertraline and olanzapine and were randomized to continue sertraline plus olanzapine or placebo for 36 weeks. Olanzapine steady state concentration (SSC) were calculated based on sparsely-sampled levels. Rates of relapse and changes in brain structure were assessed as outcomes. There were significant associations between dosage and relapse rates (N = 118; HR = 0.94, 95% CI [0.897, 0.977], p = 0.002) or changes in left cortical thickness (N = 44; B = -2.0 × 10-3, 95% CI [-3.1 × 10-3, -9.6 × 10-4], p < 0.001) and between SSC and changes in left cortical thickness (N = 44; B = -8.7 × 10-4, 95% CI [-1.4 × 10-3, -3.6 × 10-4], p = 0.001). Similar results were found for the right cortex. These associations were no longer significant when the analysis was restricted to participants treated with olanzapine. Our findings suggest that, within its therapeutic range, the effect of olanzapine on relapse or cortical thickness does not depend on its dosage or SSC. Further research is needed on the effect of olanzapine and other antipsychotics on mood symptoms and brain structure.

2.
World Psychiatry ; 23(1): 26-51, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38214624

RESUMEN

Functional neuroimaging emerged with great promise and has provided fundamental insights into the neurobiology of schizophrenia. However, it has faced challenges and criticisms, most notably a lack of clinical translation. This paper provides a comprehensive review and critical summary of the literature on functional neuroimaging, in particular functional magnetic resonance imaging (fMRI), in schizophrenia. We begin by reviewing research on fMRI biomarkers in schizophrenia and the clinical high risk phase through a historical lens, moving from case-control regional brain activation to global connectivity and advanced analytical approaches, and more recent machine learning algorithms to identify predictive neuroimaging features. Findings from fMRI studies of negative symptoms as well as of neurocognitive and social cognitive deficits are then reviewed. Functional neural markers of these symptoms and deficits may represent promising treatment targets in schizophrenia. Next, we summarize fMRI research related to antipsychotic medication, psychotherapy and psychosocial interventions, and neurostimulation, including treatment response and resistance, therapeutic mechanisms, and treatment targeting. We also review the utility of fMRI and data-driven approaches to dissect the heterogeneity of schizophrenia, moving beyond case-control comparisons, as well as methodological considerations and advances, including consortia and precision fMRI. Lastly, limitations and future directions of research in the field are discussed. Our comprehensive review suggests that, in order for fMRI to be clinically useful in the care of patients with schizophrenia, research should address potentially actionable clinical decisions that are routine in schizophrenia treatment, such as which antipsychotic should be prescribed or whether a given patient is likely to have persistent functional impairment. The potential clinical utility of fMRI is influenced by and must be weighed against cost and accessibility factors. Future evaluations of the utility of fMRI in prognostic and treatment response studies may consider including a health economics analysis.

3.
Brain Imaging Behav ; 18(1): 117-129, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37917311

RESUMEN

BACKGROUND: The neurobiology of psychotic depression is not well understood and can be confounded by antipsychotics. Magnetic resonance spectroscopy (MRS) is an ideal tool to measure brain metabolites non-invasively. We cross-sectionally assessed brain metabolites in patients with remitted psychotic depression and controls. We also longitudinally assessed the effects of olanzapine versus placebo on brain metabolites. METHODS: Following remission, patients with psychotic depression were randomized to continue sertraline + olanzapine (n = 15) or switched to sertraline + placebo (n = 18), at which point they completed an MRS scan. Patients completed a second scan either 36 weeks later, relapse, or discontinuation. Where water-scaled metabolite levels were obtained and a Point-RESolved Spectroscopy sequence was utilized, choline, myo-inositol, glutamate + glutamine (Glx), N-acetylaspartate, and creatine were measured in the left dorsolateral prefrontal cortex (L-DLPFC) and dorsal anterior cingulate cortex (dACC). An ANCOVA was used to compare metabolites between patients (n = 40) and controls (n = 46). A linear mixed-model was used to compare olanzapine versus placebo groups. RESULTS: Cross-sectionally, patients (compared to controls) had higher myo-inositol (standardized mean difference [SMD] = 0.84; 95%CI = 0.25-1.44; p = 0.005) in the dACC but not different Glx, choline, N-acetylaspartate, and creatine. Longitudinally, patients randomized to placebo (compared to olanzapine) showed a significantly greater change with a reduction of creatine (SMD = 1.51; 95%CI = 0.71-2.31; p = 0.0002) in the dACC but not glutamate + glutamine, choline, myo-inositol, and N-acetylaspartate. CONCLUSIONS: Patients with remitted psychotic depression have higher myo-inositol than controls. Olanzapine may maintain creatine levels. Future studies are needed to further disentangle the mechanisms of action of olanzapine.


Asunto(s)
Antipsicóticos , Encéfalo , Depresión , Humanos , Antipsicóticos/farmacología , Ácido Aspártico , Encéfalo/diagnóstico por imagen , Encéfalo/metabolismo , Colina/metabolismo , Creatina/metabolismo , Depresión/tratamiento farmacológico , Glutamina/metabolismo , Inositol/metabolismo , Imagen por Resonancia Magnética , Olanzapina/farmacología , Sertralina/farmacología
4.
Psychol Med ; 54(6): 1142-1151, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37818656

RESUMEN

BACKGROUND: Remitted psychotic depression (MDDPsy) has heterogeneity of outcome. The study's aims were to identify subgroups of persons with remitted MDDPsy with distinct trajectories of depression severity during continuation treatment and to detect predictors of membership to the worsening trajectory. METHOD: One hundred and twenty-six persons aged 18-85 years participated in a 36-week randomized placebo-controlled trial (RCT) that examined the clinical effects of continuing olanzapine once an episode of MDDPsy had remitted with sertraline plus olanzapine. Latent class mixed modeling was used to identify subgroups of participants with distinct trajectories of depression severity during the RCT. Machine learning was used to predict membership to the trajectories based on participant pre-trajectory characteristics. RESULTS: Seventy-one (56.3%) participants belonged to a subgroup with a stable trajectory of depression scores and 55 (43.7%) belonged to a subgroup with a worsening trajectory. A random forest model with high prediction accuracy (AUC of 0.812) found that the strongest predictors of membership to the worsening subgroup were residual depression symptoms at onset of remission, followed by anxiety score at RCT baseline and age of onset of the first lifetime depressive episode. In a logistic regression model that examined depression score at onset of remission as the only predictor variable, the AUC (0.778) was close to that of the machine learning model. CONCLUSIONS: Residual depression at onset of remission has high accuracy in predicting membership to worsening outcome of remitted MDDPsy. Research is needed to determine how best to optimize the outcome of psychotic MDDPsy with residual symptoms.


Asunto(s)
Trastorno Depresivo Mayor , Trastornos Psicóticos , Humanos , Olanzapina/uso terapéutico , Depresión , Trastorno Depresivo Mayor/diagnóstico , Trastorno Depresivo Mayor/tratamiento farmacológico , Trastornos Psicóticos/tratamiento farmacológico , Sertralina/uso terapéutico
5.
Mol Psychiatry ; 28(8): 3305-3313, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37258617

RESUMEN

The effect of antipsychotic medication on resting state functional connectivity in major depressive disorder (MDD) is currently unknown. To address this gap, we examined patients with MDD with psychotic features (MDDPsy) participating in the Study of the Pharmacotherapy of Psychotic Depression II. All participants were treated with sertraline plus olanzapine and were subsequently randomized to continue sertraline plus olanzapine or be switched to sertraline plus placebo. Participants completed an MRI at randomization and at study endpoint (study completion at Week 36, relapse, or early termination). The primary outcome was change in functional connectivity measured within and between specified networks and the rest of the brain. The secondary outcome was change in network topology measured by graph metrics. Eighty-eight participants completed a baseline scan; 73 completed a follow-up scan, of which 58 were usable for analyses. There was a significant treatment X time interaction for functional connectivity between the secondary visual network and rest of the brain (t = -3.684; p = 0.0004; pFDR = 0.0111). There was no significant treatment X time interaction for graph metrics. Overall, functional connectivity between the secondary visual network and the rest of the brain did not change in participants who stayed on olanzapine but decreased in those switched to placebo. There were no differences in changes in network topology measures when patients stayed on olanzapine or switched to placebo. This suggests that olanzapine may stabilize functional connectivity, particularly between the secondary visual network and the rest of the brain.


Asunto(s)
Antipsicóticos , Trastorno Depresivo Mayor , Humanos , Antipsicóticos/uso terapéutico , Trastorno Depresivo Mayor/tratamiento farmacológico , Olanzapina/uso terapéutico , Sertralina/uso terapéutico , Benzodiazepinas , Quimioterapia Combinada , Imagen por Resonancia Magnética
6.
J Affect Disord ; 334: 317-324, 2023 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-37149056

RESUMEN

BACKGROUND: Psychomotor disturbance is common in psychotic depression and is associated with relapse. In this analysis, we examined whether white matter microstructure is associated with relapse probability in psychotic depression and, if so, whether white matter microstructure accounts for the association between psychomotor disturbance and relapse. METHODS: We used tractography to characterize diffusion-weighted MRI data in 80 participants enrolled in a randomized clinical trial that compared efficacy and tolerability of sertraline plus olanzapine with sertraline plus placebo in the continuation treatment of remitted psychotic depression. Cox proportional hazard models tested the relationships between psychomotor disturbance (processing speed and CORE score) at baseline, white matter microstructure (fractional anisotropy [FA] and mean diffusivity [MD]) in 15 selected tracts at baseline, and relapse probability. RESULTS: CORE was significantly associated with relapse. Higher mean MD was significantly associated with relapse in the each of the following tracts: corpus callosum, left striato-frontal, left thalamo-frontal, and right thalamo-frontal. CORE and MD were each associated with relapse in the final models. LIMITATIONS: As a secondary analysis with a small sample size, this study was not powered for its aims, and is vulnerable to types I and II statistical errors. Further, the sample size was not sufficient to test the interaction of the independent variables and randomized treatment group with relapse probability. CONCLUSIONS: While both psychomotor disturbance and MD were associated with psychotic depression relapse, MD did not account for the relationship between psychomotor disturbance and relapse. The mechanism by which of psychomotor disturbance increases the risk of relapse requires further investigation. CLINICAL TRIAL REGISTRATION: Study of the Pharmacotherapy of Psychotic Depression II (STOP-PD II); NCT01427608. URL: https://clinicaltrials.gov/ct2/show/NCT01427608.


Asunto(s)
Trastorno Depresivo Mayor , Trastornos Psicóticos , Sustancia Blanca , Humanos , Sustancia Blanca/diagnóstico por imagen , Sertralina/uso terapéutico , Depresión , Trastorno Depresivo Mayor/diagnóstico por imagen , Trastorno Depresivo Mayor/tratamiento farmacológico , Trastornos Psicóticos/diagnóstico por imagen , Trastornos Psicóticos/tratamiento farmacológico , Encéfalo , Anisotropía
7.
J Psychiatr Res ; 157: 285-290, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36535116

RESUMEN

Psychotic depression has a high rate of relapse. The study aims were to identify a prediction model of risk of relapse of psychotic depression and examine whether predictors moderated the effect of treatment on relapse. One hundred and twenty-six men and women aged 18-85 years, who experienced sustained remission or near-remission of psychotic depression with sertraline plus olanzapine, participated in a 36-week randomized controlled trial that compared sertraline plus olanzapine with sertraline plus placebo in preventing relapse (NCT01427608). Cox regression analyses were performed to identify significant predictors of relapse and to model the combined role of significant predictors. Concordance statistic was calculated to determine the accuracy of the best fit multivariable models in predicting relapse. Finally, interaction terms were tested for each significant predictor to examine whether they moderated the effect of treatment on risk of relapse. Lifetime number of depressive episodes, severity of residual depressive symptoms at the time of randomization, and psychomotor disturbance both at acute enrollment when participants were depressed and at the time of randomization predicted risk of relapse. Multivariable models had 69-70% accuracy in predicting relapse. Psychomotor disturbance was associated with increased risk of relapse in the sertraline plus olanzapine group compared with sertraline plus placebo, whereas the other predictors did not moderate the effect of treatment on relapse. Future research is needed to determine whether a combination of clinical and biological variables can further increase the accuracy of prediction of relapse of psychotic depression.


Asunto(s)
Antipsicóticos , Sertralina , Masculino , Femenino , Humanos , Olanzapina/uso terapéutico , Sertralina/uso terapéutico , Sertralina/efectos adversos , Antipsicóticos/efectos adversos , Depresión , Benzodiazepinas , Quimioterapia Combinada , Método Doble Ciego , Enfermedad Crónica , Resultado del Tratamiento
8.
J Clin Psychopharmacol ; 42(5): 489-494, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35977030

RESUMEN

BACKGROUND: In the 1980s, the response rate of major depressive disorder with psychotic features (MDD-Psy) to placebo pills was reported to be close to 0%. To our knowledge, this placebo response rate has not been systematically reassessed. We undertook a systematic review of randomized controlled trials (RCTs) that have used a placebo or sham control group for MDD-Psy. METHODS: We searched MEDLINE and identified 9 relevant publications reporting on 10 studies comparing a placebo or sham interventions versus an active intervention. We extracted reported rates of response or of dropout for all causes associated with placebo versus active intervention(s) and aggregated response and dropout rates across trials. RESULTS: Two sham-controlled electroconvulsive therapy (ECT) trials did not provide response rates. In the 3 pharmacotherapy studies published in the 1980s, 0 of 12 participants (0%) responded to placebo versus 13 of 38 (34.2%) responding to the active interventions. In contrast, 5 RCTs published in the 2000s, 114 of 339 participants (33.6%) randomized to placebo responded versus 149 of 373 participants (39.9%) randomized to active interventions; dropout rates were 71/236 (30.1%) for placebo versus 84/282 (29.8%) for the active interventions. CONCLUSIONS: As expected, response rates to placebo pills in RCTs for MDD-Psy increased markedly from the 1980s to the 2000s. Methodological issues in the design and conduct of more recent RCTs may have contributed to the high placebo response. However, one needs to consider this placebo response rate when interpreting the result of recent trials of MDD-Psy, which typically have not included a "pure" placebo condition.


Asunto(s)
Trastorno Depresivo Mayor , Humanos , Antidepresivos/uso terapéutico , Trastorno Depresivo Mayor/tratamiento farmacológico , Efecto Placebo , Ensayos Clínicos Controlados Aleatorios como Asunto
9.
Psychiatry Res ; 314: 114648, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35623239

RESUMEN

The CORE instrument is commonly used to measure psychomotor disturbance. We examined the factor structure of the CORE in 266 adults with an acute episode psychotic depression, a disorder with a high rate of psychomotor disturbance. Exploratory factor analysis identified a two-factor solution: Factor 1 corresponded to the CORE's retardation and non-interactiveness items and Factor 2 corresponded to its agitation items. Internal consistency was excellent for Factor 1 but questionable for Factor 2. These findings suggest that the CORE's retardation and non-interactiveness items should be combined in one subscale when assessing patients with an acute episode of psychotic depression.


Asunto(s)
Trastorno Bipolar , Trastorno Depresivo Mayor , Trastornos Psicóticos , Adulto , Depresión , Trastorno Depresivo Mayor/complicaciones , Análisis Factorial , Humanos , Trastornos Psicóticos/complicaciones
10.
Psychol Med ; : 1-7, 2021 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-33766150

RESUMEN

BACKGROUND: Little is known about the relationship between psychomotor disturbance (PMD) and treatment outcome of psychotic depression. This study examined the association between PMD and subsequent remission and relapse of treated psychotic depression. METHODS: Two hundred and sixty-nine men and women aged 18-85 years with an episode of psychotic depression were treated with open-label sertraline plus olanzapine for up to 12 weeks. Participants who remained in remission or near-remission following an 8-week stabilization phase were eligible to participate in a 36-week randomized controlled trial (RCT) that compared the efficacy and tolerability of sertraline plus olanzapine (n = 64) with sertraline plus placebo (n = 62). PMD was measured with the psychiatrist-rated sign-based CORE at acute phase baseline and at RCT baseline. Spearman's correlations and logistic regression analyses were used to analyze the association between CORE total score at acute phase baseline and remission/near-remission and CORE total score at RCT baseline and relapse. RESULTS: Higher CORE total score at acute phase baseline was associated with lower frequency of remission/near-remission. Higher CORE total score at RCT baseline was associated with higher frequency of relapse, in the RCT sample as a whole, as well as in each of the two randomized groups. CONCLUSIONS: PMD is associated with poorer outcome of psychotic depression treated with sertraline plus olanzapine. Future research needs to examine the neurobiology of PMD in psychotic depression in relation to treatment outcome.

11.
JAMA Psychiatry ; 77(7): 674-683, 2020 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-32101271

RESUMEN

Importance: Prescriptions for antipsychotic medications continue to increase across many brain disorders, including off-label use in children and elderly individuals. Concerning animal and uncontrolled human data suggest antipsychotics are associated with change in brain structure, but to our knowledge, there are no controlled human studies that have yet addressed this question. Objective: To assess the effects of antipsychotics on brain structure in humans. Design, Setting, and Participants: Prespecified secondary analysis of a double-blind, randomized, placebo-controlled trial over a 36-week period at 5 academic centers. All participants, aged 18 to 85 years, were recruited from the multicenter Study of the Pharmacotherapy of Psychotic Depression II (STOP-PD II). All participants had major depressive disorder with psychotic features (psychotic depression) and were prescribed olanzapine and sertraline for a period of 12 to 20 weeks, which included 8 weeks of remission of psychosis and remission/near remission of depression. Participants were then were randomized to continue receiving this regimen or to be switched to placebo and sertraline for a subsequent 36-week period. Data were analyzed between October 2018 and February 2019. Interventions: Those who consented to the imaging study completed a magnetic resonance imaging (MRI) scan at the time of randomization and a second MRI scan at the end of the 36-week period or at time of relapse. Main Outcomes and Measures: The primary outcome measure was cortical thickness in gray matter and the secondary outcome measure was microstructural integrity of white matter. Results: Eighty-eight participants (age range, 18-85 years) completed a baseline scan; 75 completed a follow-up scan, of which 72 (32 men and 40 women) were useable for final analyses. There was a significant treatment-group by time interaction in cortical thickness (left, t = 3.3; P = .001; right, t = 3.6; P < .001) but not surface area. No significant interaction was found for fractional anisotropy, but one for mean diffusivity of the white matter skeleton was present (t = -2.6, P = .01). When the analysis was restricted to those who sustained remission, exposure to olanzapine compared with placebo was associated with significant decreases in cortical thickness in the left hemisphere (ß [SE], 0.04 [0.009]; t34.4 = 4.7; P <.001), and the right hemisphere (ß [SE], 0.03 [0.009]; t35.1 = 3.6; P <.001). Post hoc analyses showed that those who relapsed receiving placebo experienced decreases in cortical thickness compared with those who sustained remission. Conclusions and Relevance: In this secondary analysis of a randomized clinical trial, antipsychotic medication was shown to change brain structure. This information is important for prescribing in psychiatric conditions where alternatives are present. However, adverse effects of relapse on brain structure support antipsychotic treatment during active illness. Trial Registration: ClinicalTrials.gov Identifier: NCT01427608.


Asunto(s)
Antipsicóticos/farmacología , Corteza Cerebral , Trastorno Depresivo Mayor , Olanzapina/farmacología , Evaluación de Resultado en la Atención de Salud , Trastornos Psicóticos , Sertralina/farmacología , Sustancia Blanca , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Corteza Cerebral/diagnóstico por imagen , Corteza Cerebral/efectos de los fármacos , Corteza Cerebral/patología , Trastorno Depresivo Mayor/diagnóstico por imagen , Trastorno Depresivo Mayor/tratamiento farmacológico , Trastorno Depresivo Mayor/patología , Imagen de Difusión Tensora , Método Doble Ciego , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Trastornos Psicóticos/diagnóstico por imagen , Trastornos Psicóticos/tratamiento farmacológico , Trastornos Psicóticos/patología , Sustancia Blanca/diagnóstico por imagen , Sustancia Blanca/efectos de los fármacos , Sustancia Blanca/patología , Adulto Joven
12.
Neuropsychopharmacology ; 45(7): 1223-1231, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32109935

RESUMEN

Major depressive disorder with psychotic features (psychotic depression) is a severe disorder. Compared with other psychotic disorders such as schizophrenia, relatively few studies on the neurobiology of psychotic depression have been pursued. Neuroimaging studies investigating psychotic depression have provided evidence for distributed structural brain abnormalities implicating the insular cortex and limbic system. We examined structural brain networks in participants (N = 245) using magnetic resonance imaging. This sample included healthy controls (n = 159) and the largest cross-sectional sample of patients with remitted psychotic depression (n = 86) collected to date. All patients participated in the Study of Pharmacotherapy of Psychotic Depression II randomized controlled trial. We used a novel, whole-brain, data-driven parcellation technique-non-negative matrix factorization-and applied it to cortical thickness data to derive structural covariance networks. We compared patients with remitted psychotic depression to healthy controls and found that patients had significantly thinner cortex in five structural covariance networks (insular-limbic, occipito-temporal, temporal, parahippocampal-limbic, and inferior fronto-temporal), confirming our hypothesis that affected brain networks would incorporate cortico-limbic regions. We also found that cross-sectional depression and severity scores at the time of scanning were associated with the insular-limbic network. Furthermore, the insular-limbic network predicted future severity scores that were collected at the time of recurrence of psychotic depression or sustained remission. Overall, decreased cortical thickness was found in five structural brain networks in patients with remitted psychotic depression and brain-behavior relationships were observed, particularly between the insular-limbic network and illness severity.


Asunto(s)
Encéfalo , Trastorno Depresivo Mayor , Trastornos Psicóticos , Encéfalo/diagnóstico por imagen , Estudios Transversales , Depresión , Trastorno Depresivo Mayor/diagnóstico por imagen , Trastorno Depresivo Mayor/tratamiento farmacológico , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Trastornos Psicóticos/diagnóstico por imagen , Trastornos Psicóticos/tratamiento farmacológico
13.
BMJ Glob Health ; 4(5): e001853, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31750000

RESUMEN

BACKGROUND: Collaborations are often a cornerstone of global health research. Power dynamics can shape if and how local researchers are included in manuscripts. This article investigates how international collaborations affect the representation of local authors, overall and in first and last author positions, in African health research. METHODS: We extracted papers on 'health' in sub-Saharan Africa indexed in PubMed and published between 2014 and 2016. The author's affiliation was used to classify the individual as from the country of the paper's focus, from another African country, from Europe, from the USA/Canada or from another locale. Authors classified as from the USA/Canada were further subclassified if the author was from a top US university. In primary analyses, individuals with multiple affiliations were presumed to be from a high-income country if they contained any affiliation from a high-income country. In sensitivity analyses, these individuals were presumed to be from an African country if they contained any affiliation an African country. Differences in paper characteristics and representation of local coauthors are compared by collaborative type using χ² tests. RESULTS: Of the 7100 articles identified, 68.3% included collaborators from the USA, Canada, Europe and/or another African country. 54.0% of all 43 429 authors and 52.9% of 7100 first authors were from the country of the paper's focus. Representation dropped if any collaborators were from USA, Canada or Europe with the lowest representation for collaborators from top US universities-for these papers, 41.3% of all authors and 23.0% of first authors were from country of paper's focus. Local representation was highest with collaborators from another African country. 13.5% of all papers had no local coauthors. DISCUSSION: Individuals, institutions and funders from high-income countries should challenge persistent power differentials in global health research. South-South collaborations can help African researchers expand technical expertise while maintaining presence on the resulting research.

14.
Neuroimage ; 199: 325-335, 2019 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-31176833

RESUMEN

During word and object recognition, extensive activation has consistently been observed in the left ventral occipito-temporal cortex (vOT), focused around the occipito-temporal sulcus (OTs). Previous studies have shown that there is a hierarchy of responses from posterior to anterior vOT regions (along the y-axis) that corresponds with increasing levels of recognition - from perceptual to semantic processing, respectively. In contrast, the functional differences between superior and inferior vOT responses (i.e. along the z-axis) have not yet been elucidated. To investigate, we conducted an extensive review of the literature and found that peak activation for reading varies by more than 1 cm in the z-axis. In addition, we investigated functional differences between superior and inferior parts of left vOT by analysing functional MRI data from 58 neurologically normal skilled readers performing 8 different visual processing tasks. We found that group activation in superior vOT was significantly more sensitive than inferior vOT to the type of task, with more superior vOT activation when participants were matching visual stimuli for their semantic or perceptual content than producing speech to the same stimuli. This functional difference along the z-axis was compared to existing boundaries between cytoarchitectonic areas around the OTs. In addition, using dynamic causal modelling, we show that connectivity from superior vOT to anterior vOT increased with semantic content during matching tasks but not during speaking tasks whereas connectivity from inferior vOT to anterior vOT was sensitive to semantic content for matching and speaking tasks. The finding of a functional dissociation between superior and inferior parts of vOT has implications for predicting deficits and response to rehabilitation for patients with partial damage to vOT following stroke or neurosurgery.


Asunto(s)
Mapeo Encefálico , Lóbulo Occipital/fisiología , Reconocimiento Visual de Modelos/fisiología , Lectura , Lóbulo Temporal/fisiología , Adolescente , Adulto , Anciano , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Lóbulo Occipital/diagnóstico por imagen , Lóbulo Temporal/diagnóstico por imagen , Adulto Joven
16.
EBioMedicine ; 36: 446-453, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-30287158

RESUMEN

BACKGROUND: There is paucity of neurobiological knowledge about major depressive disorder with psychotic features ("psychotic depression"). This study addresses this knowledge gap by using resting state functional magnetic resonance imaging (R-fMRI) to compare functional connectivity in patients with psychotic depression and healthy controls. METHODS: We scanned patients who participated in a randomized controlled trial as well as healthy controls. All patients achieved remission from depressive and psychotic symptoms with sertraline and olanzapine. We employed Independent Component Analysis in independent samples to isolate the default mode network (DMN) and compared patients and controls. FINDINGS: The Toronto sample included 28 patients (mean [SD], age 56·2 [13·7]) and 39 controls (age 55·1 [13·5]). The Replication sample included 29 patients (age 56·1 [17·7]) and 36 controls (age 48·3 [17·9]). Patients in the Toronto sample demonstrated decreased between-network functional connectivity between the DMN and bilateral insular, somatosensory/motor, and auditory cortices with peak activity in the right planum polare (t = 4·831; p = 0·001, Family Wise Error (FWE) corrected). A similar pattern of between-network functional connectivity was present in our Replication sample with peak activity in the right precentral gyrus (t = 4·144; p = 0·003, FWE corrected). INTERPRETATION: Remission from psychotic depression is consistently associated with an absence of increased DMN-related functional connectivity and presence of decreased between-network functional connectivity. Future research will evaluate this abnormal DMN-related functional connectivity as a potential biomarker for treatment trajectories. FUNDING: National Institute of Mental Health.


Asunto(s)
Encéfalo/fisiopatología , Conectoma , Depresión/psicología , Trastorno Depresivo Mayor/psicología , Descanso/psicología , Adulto , Anciano , Mapeo Encefálico , Estudios de Casos y Controles , Trastorno Depresivo Mayor/fisiopatología , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Ontario
17.
Psychiatr Q ; 89(4): 855-867, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-29785673

RESUMEN

The neurobiological basis of bipolar disorders (BD) has received increased attention and several brain regions and brain circuits have been correlated with clinical symptoms. These brain regions and circuits may represent targets for neuromodulation techniques such as transcranial Direct Current Stimulation (tDCS). We systematically reviewed the literature to explore the risks and benefits of tDCS in BD and examined all mood states. Following the PRISMA guidelines, a systematic literature search using several databases was performed from April 2002 to June 2017. From the 135 eligible studies, we retained 19 relevant articles for the systematic review, including 170 patients with BD treated by tDCS. Data from 10 studies suggest that tDCS improves depressive symptoms in BD. One case report of add-on-tDCS reported a significant positive response on manic symptoms. In 4 studies, tDCS impacted specific neurocognitive functions in euthymic patients. There is also preliminary evidence that tDCS improves neurological soft signs and sleep quality in euthymia. Side effects were predominantly transient and low-intensity, although 6 cases of hypomanic/manic affective switches have been reported. The majority of studies have been open trials with few patients. More sufficiently powered randomized controlled trials are needed to clarify the effectiveness of tDCS. Preliminary data suggests that tDCS holds promise as a treatment for BD, especially during depressive episodes. Perhaps most promising are emerging data suggesting tDCS may impact neurocognition and sleep quality in euthymia and be useful for relapse prevention.


Asunto(s)
Trastorno Bipolar/terapia , Disfunción Cognitiva/terapia , Depresión/terapia , Evaluación de Resultado en la Atención de Salud , Trastornos del Sueño-Vigilia/terapia , Estimulación Transcraneal de Corriente Directa/métodos , Trastorno Bipolar/complicaciones , Disfunción Cognitiva/etiología , Humanos , Trastornos del Sueño-Vigilia/etiología
18.
Artículo en Inglés | MEDLINE | ID: mdl-28552295

RESUMEN

OBJECTIVE: Bipolar disorder (BD) is a severe and recurrent brain disorder that can manifest in manic or depressive episodes. Transcranial Direct Current Stimulation (tDCS) has been proposed as a novel therapeutic modality for patients experiencing bipolar depression, for which standard treatments are often inefficient. While several studies have been conducted in this patient group, there has been no systematic review or meta-analysis that specifically examines bipolar depression. We aimed to address this gap in the literature and evaluated the efficacy and tolerability of tDCS in patients fulfilling DSM-IV-TR criteria for BD I, II, or BD not otherwise specified (NOS). METHODS: We systematically searched the literature from April 2002 to November 2016 to identify relevant publications for inclusion in our systematic review and meta-analysis. Effect sizes for depression rating-scale scores were expressed as the standardized mean difference (SMD) before and after tDCS. RESULTS: Thirteen of 382 identified studies met eligibility criteria for our systematic review. The meta-analysis included 46 patients from 7 studies with depression rating-scale scores pre- and post-tDCS. Parameters of tDCS procedures were heterogeneous. Depression scores decreased significantly with a medium effect size after acute-phase of treatment (SMD 0.71 [0.25-1.18], z=3.00, p=0.003) and at the furthest endpoint (SMD 1.27 [0.57-1.97], z=3.57, p=0.0004). Six cases of affective switching under tDCS treatment protocols were observed. CONCLUSIONS: Depressive symptoms respond to tDCS in patients with BD. Additional studies, and particularly randomized controlled trials, are needed to clarify the effectiveness of tDCS in bipolar depression, the frequency of tDCS-emergent hypomania/mania, and which tDCS modalities are most efficient.


Asunto(s)
Trastorno Bipolar/terapia , Estimulación Transcraneal de Corriente Directa , Humanos , Resultado del Tratamiento
19.
J Psychiatr Pract ; 23(1): 25-35, 2017 01.
Artículo en Inglés | MEDLINE | ID: mdl-28072642

RESUMEN

Helicobacter pylori infects half the global population. Because serious complications can result from this infection, a so-called "triple therapy" is recommended: treatment with a proton-pump inhibitor and clarithromycin, along with amoxicillin or metronidazole. Although these antibiotics have been associated with neuropsychiatric symptoms, it is difficult to disentangle the effects of antibiotics from the effects of acute infections that may precipitate acute neuropsychiatric symptoms. Study of patients with chronic H. pylori infections who undergo antibiotic treatment may provide a clearer view of the associations between acute neuropsychiatric symptoms and antibiotics. The literature concerning this association in patients with H. pylori has not been reviewed. We therefore undertook a review of MEDLINE and postmarket surveillance data concerning this issue and identified 25 cases. Postmarket data indicated that gastrointestinal symptoms were the most commonly reported adverse reactions, followed by neurological adverse reactions; neuropsychiatric symptoms were less commonly reported, with variable and nonspecific terminology used to describe them. More specific, yet still variable terminology was found in the literature. Anxiety, delirium, dissociation, mania, and psychosis were reported, with approximately half of these neuropsychiatric symptoms occurring without symptoms of delirium. The use of standardized neuropsychiatric symptom rating scales and the Confusion Assessment Method for monitoring adverse reactions may improve our knowledge of neuropsychiatric symptoms and their association with antibiotics and thus mitigate underreporting. Physicians should remain alert to the possibility that neuropsychiatric symptoms may occur during antibiotic treatment of H. pylori and recognize that rapid resolution typically occurs with discontinuation of the antibiotics.


Asunto(s)
Antibacterianos/efectos adversos , Infecciones por Helicobacter/tratamiento farmacológico , Trastornos Mentales/inducido químicamente , Enfermedades del Sistema Nervioso/inducido químicamente , Humanos
20.
J Psychiatr Res ; 62: 23-30, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25684151

RESUMEN

BACKGROUND: Electroconvulsive therapy (ECT) remains one of the most effective tools in the psychiatric treatment armamentarium, particularly for refractory depression. Yet, there remains a subset of patients who do not respond to ECT or for whom clinically adequate seizures cannot be elicited, for whom ketamine has emerged as a putative augmentation agent. METHODS: We searched EMBASE, PsycINFO, CENTRAL, and MEDLINE from 1962 to April 2014 to identify randomized controlled trials evaluating ketamine in ECT (PROSPERO #CRD42014009035). Clinical remission, response, and change in depressive symptom scores were extracted by two independent raters. Adverse events were recorded. Drop-outs were assessed as a proxy for acceptability. Meta-analyses employed a random effects model. RESULTS: Data were synthesized from 5 RCTs, representing a total of 182 patients with major depressive episodes (n = 165 Major Depressive Disorder, n = 17 Bipolar Disorder). ECT with ketamine augmentation was not associated with higher rates of clinical remission (Risk Difference (RD) = 0.00; 95%CI = -0.08 to 0.10), response (RD = -0.01; 95%CI = -0.11 to 0.08), or improvements in depressive symptoms (SMD = 0.38; 95%CI = -0.41 to 1.17). Ketamine augmentation was associated with higher rates of confusion/disorientation/prolonged delirium (OR = 6.59, 95%CI: 1.28-33.82, NNH = 3), but not agitation, hypertension or affective switches. CONCLUSION: Our meta-analysis of randomized controlled trials of ketamine augmentation in the ECT setting suggests a lack of clinical efficacy, and an increased likelihood of confusion. Individuals for whom adequate seizures or therapeutic response cannot be obtained have not been studied using randomized controlled designs. Additional research is required to address the role of ketamine in this population.


Asunto(s)
Anticonvulsivantes/uso terapéutico , Terapia Electroconvulsiva/métodos , Epilepsia/terapia , Ketamina/uso terapéutico , Animales , Humanos , Ensayos Clínicos Controlados Aleatorios como Asunto
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