Revistas
Revista:
JOURNAL OF THE AMERICAN ACADEMY OF CHILD AND ADOLESCENT PSYCHIATRY
ISSN:
0890-8567
Año:
2024
Vol.:
63
N°:
2
Págs.:
154-171
Revista:
PSYCHOLOGICAL MEDICINE
ISSN:
0033-2917
Año:
2023
Vol.:
53
N°:
16
Págs.:
7883 - 7892
Abstract
Background
Intimate partner violence (IPV) and sexual violence (SV) are significant problems world-wide, and they affect women disproportionally. Whether individuals with attention-deficit/hyperactivity disorder (ADHD) are at an increased risk of being involved in these types of violence is unclear.
Methods
We carried out a systematic review and meta-analysis (PROSPERO registration CRD42022348165) of the associations between ADHD and being the victim or perpetrator of IPV and SV. Ratios of occurrence of violence were pooled in random-effects models and study risk of bias was evaluated using the Newcastle¿Ottawa Scale.
Results
A search on multiple databases, carried out on 7 October 2022, yielded 14 eligible studies (1 111 557 individuals). Analyses showed a higher risk of ADHD individuals being involved in IPV as perpetrators (six studies, OR 2.5, 95% CI 1.51¿4.15) or victims (four studies, OR 1.78, 95% CI 1.06¿3.0). Likewise, individuals with ADHD were at increased risk of being perpetrators (three studies, OR 2.73, 95% CI 1.35¿5.51) or victims of SV (six studies, OR 1.84, 95% CI 1.51¿2.24). Results were overall robust to different analytical choices.
Conclusions
Individuals with ADHD are at an increased risk of being involved in cases of violence, namely IPV and SV, either as victims or perpetrators. Although the causal path or mediating variables for these results are still unclear, this increased risk should inform evidence-based psychoeducation with individuals with ADHD, their families, and partners about romantic relationships and sexuality.
Autores:
Cortese, S.; Gabellone, A.; Marzulli, L.; et al.
Revista:
NEUROSCIENCE AND BIOBEHAVIORAL REVIEWS
ISSN:
0149-7634
Año:
2022
Vol.:
136
Págs.:
104592
There is mixed evidence on the link between autism spectrum disorder (ASD) and diabetes. We conducted the first systematic review/meta-analysis on their association. Based on a pre-registered protocol (PROSPERO: CRD42021261114), we searched Pubmed, Ovid, and Web of Science databases up to 6 December 2021, with no language/type of document restrictions. We assessed study quality using the Newcastle-Ottawa Scale (NOS). We included 24 studies (total: 3427,773 individuals; 237,529 with ASD and 92,832 with diabetes) in the systematic review and 20 in the meta-analysis (mean stars number on the NOS: 5.89/10). There was a significant association, albeit characterized by significant heterogeneity, when pooling unadjusted OR (1.535, 95% CI = 1.109¿2.126), which remained significant when restricting the analysis to children and type 2 diabetes, but became non-significant when considering adjusted ORs (OR: 1.528, 95% CI = 0.954¿2.448). No significant prospective association was found (n = 2) on diabetes predicting ASD (HR: 1.232, 0.826¿11.837). Therefore, the association between ASD and diabetes is likely confounded by demographic and clinical factors that should be systematically investigated in future studies.
Revista:
NEUROSCIENCE AND BIOBEHAVIORAL REVIEWS
ISSN:
0149-7634
Año:
2022
Vol.:
137
Págs.:
104662
We mapped the evidence on the type and strength of associations between a broad range of mental and physical conditions in children and adolescents, by carrying out an umbrella review, i.e., a quantitative synthesis of previous systematic reviews and meta-analyses. We also assessed to which extent the links between mental and physical conditions vary across disorders or, by contrast, are transdiagnostic. Based on a pre-established protocol, we retained 45 systematic reviews/meta-analyses, encompassing around 12.5 million of participants. In analyses limited to the most rigorous estimates, we found evidence for the following associations: ADHD-asthma, ADHD-obesity, and depression-asthma. A transdiagnostic association was confirmed between asthma and anxiety/ASD/depression/bipolar disorder, between obesity and ADHD/ASD/depression, and between dermatitis and ASD/ADHD. We conclude that obesity and allergic conditions are likely to be associated with mental disorders in children and adolescents. Our results can help clinicians explore potential links between mental and physical conditions in children/adolescent and provide a road map for future studies aimed at shading light on the underlying factors.
Autores:
Solmi, M.; Estradé, A.; Thompson, T.; et al.
Revista:
JOURNAL OF AFFECTIVE DISORDERS
ISSN:
0165-0327
Año:
2022
Vol.:
299
Págs.:
367 - 376
Background
The COVID-19 pandemic has altered daily routines and family functioning, led to closing schools, and dramatically limited social interactions worldwide. Measuring its impact on mental health of vulnerable children and adolescents is crucial.
Methods
The Collaborative Outcomes study on Health and Functioning during Infection Times (COH-FIT ¿ www.coh-fit.com) is an on-line anonymous survey, available in 30 languages, involving >230 investigators from 49 countries supported by national/international professional associations. COH-FIT has thee waves (until the pandemic is declared over by the WHO, and 6¿18 months plus 24¿36 months after its end). In addition to adults, COH-FIT also includes adolescents (age 14¿17 years), and children (age 6¿13 years), recruited via non-probability/snowball and representative sampling and assessed via self-rating and parental rating. Non-modifiable/modifiable risk factors/treatment targets to inform prevention/intervention programs to promote health and prevent mental and physical illness in children and adolescents will be generated by COH-FIT. Co-primary outcomes are changes in well-being (WHO-5) and a composite psychopathology P-Score. Multiple behavioral, family, coping strategy and service utilization factors are also assessed, including functioning and quality of life.
Results
Up to June 2021, over 13,000 children and adolescents from 59 countries have participated in the COH-FIT project, with representative samples from eleven countries.
Limitations
Cross-sectional and anonymous design.
Conclusions
Evidence generated by COH-FIT will provide an international estimate of the COVID-19 effect on children's, adolescents¿ and families¿, mental and physical health, well-being, functioning and quality of life, informing the formulation of present and future evidence-based interventions and policies to minimize adverse effects of the present and future pandemics on youth.
Revista:
JOURNAL OF THE AMERICAN ACADEMY OF CHILD AND ADOLESCENT PSYCHIATRY
ISSN:
0890-8567
Año:
2022
Vol.:
61
N°:
8
Págs.:
982 - 996
Objective
This systematic review and meta-analysis aimed to (1) determine the accuracies of a broad range of screening tools for ADHD in children and adolescents and (2) compare the diagnostic accuracy of tools between population-based and clinical/high-risk samples, and across reporters.
Method
MEDLINE, PsycINFO, EMBASE and PubMed were searched up until February 20th, 2020 with no language restrictions. Studies reporting diagnostic accuracy of a screening tool against a diagnosis of ADHD in children <18 years were eligible for inclusion. Meta-analyses were undertaken to provide pooled estimates of the area under the curve (AUC), and sensitivity and specificity of groups of measures.
Results
Seventy-five studies published between 1985 and 2021 reporting on 41 screening tools that were grouped into four categories (ASEBA, DSM-IV symptom scales, SDQ, and Other Scales) were retained. The pooled AUC for studies using a combined ADHD symptoms score was 0.82 (95% CI 0.78-0.86), although this varied considerably across reporters (0.67-0.92) and populations (0.60-0.95). None of the measures met minimal standards for acceptable sensitivity (0.8) and specificity (0.8).
Conclusion
Most tools have excellent overall diagnostic accuracy as indicated by the AUC. However, a single measure, completed by a single reporter is unlikely to have sufficient sensitivity and specificity for clinical use or population screening.
Autores:
Solmi, M.; Estradé, A.; Thompson, T.; et al.
Revista:
JOURNAL OF AFFECTIVE DISORDERS
ISSN:
0165-0327
Año:
2022
Vol.:
299
Págs.:
393 - 407
Background: . High-quality comprehensive data on short-/long-term physical/mental health effects of the COVID-19 pandemic are needed.
Methods: . The Collaborative Outcomes study on Health and Functioning during Infection Times (COH-FIT) is an international, multi-language (n=30) project involving >230 investigators from 49 countries/territories/regions, endorsed by national/international professional associations. COH-FIT is a multi-wave, on-line anonymous, cross-sectional survey [wave 1: 04/2020 until the end of the pandemic, 12 months waves 2/3 starting 6/24 months threreafter] for adults, adolescents (14-17), and children (6-13), utilizing non-probability/snowball and representative sampling. COH-FIT aims to identify non-modifiable/modifiable risk factors/treatment targets to inform prevention/intervention programs to improve social/health outcomes in the general population/vulnerable subgrous during/after COVID-19. In adults, co-primary outcomes are change from pre-COVID-19 to intra-COVID-19 in well-being (WHO-5) and a composite psychopathology P-Score. Key secondary outcomes are a P-extended score, global mental and physical health. Secondary outcomes include health-service utilization/functioning, treatment adherence, functioning, symptoms/behaviors/emotions, substance use, violence, among others.
Results: . Starting 04/26/2020, up to 14/07/2021 >151,000 people from 155 countries/territories/regions and six continents have participated. Representative samples of ¿1,000 adults have been collected in 15 countries. Overall, 43.0% had prior physical disorders, 16.3% had prior mental disorders, 26.5% were health care workers, 8.2% were aged ¿65 years, 19.3% were exposed to someone infected with COVID-19, 76.1% had been in quarantine, and 2.1% had been COVID 19-positive.
Limitations: . Cross-sectional survey, preponderance of non-representative participants.
Conclusions: . Results from COH-FIT will comprehensively quantify the impact of COVID-19, seeking to identify high-risk groups in need for acute and long-term intervention, and inform evidence-based health policies/strategies during this/future pandemics.
Autores:
Cortese, S. (Autor de correspondencia); Arrondo, Gonzalo; Correll, C. U.; et al.
Revista:
JCPP ADVANCES
ISSN:
2692-9384
Año:
2021
Vol.:
1
N°:
4
Págs.:
e12051
Autores:
Correll, C.; Cortese, S.; Croatto, G.; et al.
Revista:
WORLD PSYCHIATRY
ISSN:
1723-8617
Año:
2021
Vol.:
20
N°:
2
Págs.:
244 - 275
Top-tier evidence on the safety/tolerability of 80 medications in children/adolescents with mental disorders has recently been reviewed in this jour-nal. To guide clinical practice, such data must be combined with evidence on efficacy and acceptability. Besides medications, psychosocial inter-ventions and brain stimulation techniques are treatment options for children/adolescents with mental disorders. For this umbrella review, we systematically searched network meta-analyses (NMAs) and meta-analyses (MAs) of randomized controlled trials (RCTs) evaluating 48 medications, 20 psychosocial interventions, and four brain stimulation techniques in children/adolescents with 52 different mental disorders or groups of mental disorders, reporting on 20 different efficacy/acceptability outcomes. Co-primary outcomes were disease-specific symptom reduction and all-cause discontinuation ("acceptability"). We included 14 NMAs and 90 MAs, reporting on 15 mental disorders or groups of mental disorders. Overall, 21 medications outperformed placebo regarding the co-primary outcomes, and three psychosocial interventions did so (while seven outperformed waiting list/no treatment). Based on the meta-analytic evidence, the most convincing efficacy profile emerged for amphetamines, methylphenidate and, to a smaller extent, behavioral therapy in attention-deficit/hyperactivity disorder; aripiprazole, risperidone and several psychosocial interventions in autism; risperidone and behavioral interventions in disruptive behavior disorders; several antipsychotics in schizophrenia spectrum disorders; fluoxetine, the combination of fluoxetine and cognitive behavioral therapy (CBT), and interpersonal therapy in depression; aripiprazole in mania; fluoxetine and group CBT in anxiety disorders; fluoxetine/selective serotonin reuptake inhibitors, CBT, and behavioral therapy with exposure and response prevention in obsessive-compulsive disorder; CBT in post-traumatic stress disorder; imipramine and alarm behavioral intervention in enuresis; behavioral therapy in encopresis; and family therapy in anorexia nervosa. Results from this umbrella review of interventions for mental disorders in children/adolescents provide evidence-based information for clinical decision making.
Revista:
FRONTIERS IN PSYCHOLOGY
ISSN:
1664-1078
Año:
2021
Vol.:
12
Págs.:
652948
Background: The use of electronic interventions to improve reading is becoming a common resource. This systematic review aims to describe the main characteristics of randomized controlled trials or quasi-experimental studies that have used these tools to improve first-language reading, in order to highlight the features of the most reliable studies and guide future research.
Methods: The whole procedure followed the PRISMA guidelines, and the protocol was registered before starting the process (doi: 10.17605/OSF.IO/CKM4N). Searches in Scopus, PubMed, Web of Science and an institutional reference aggregator (Unika) yielded 6,230 candidate articles. After duplicate removal, screening, and compliance of eligibility criteria, 55 studies were finally included.
Results: They were research studies on improving first-language reading, both in children and adults, and including a control group. Thirty-three different electronic tools were employed, most of them in English, and studies were very diverse in sample size, length of intervention, and control tasks. Risk of bias was analyzed with the PEDro scale, and all studies had a medium or low risk. However, risk of bias due to conflicts of interest could not be evaluated in most studies, since they did not include a statement on this issue.
Conclusion: Future research on this topic should include randomized intervention and control groups, with sample sizes over 65 per group, interventions longer than 15 h, and a proper disclosure.
Autores:
Knolle, F.; Garofalo, S. ; Viviani, R.; et al.
Revista:
NEUROIMAGE. CLINICAL
ISSN:
2213-1582
Año:
2020
Vol.:
27
Págs.:
102277
Objective
Current research does not provide a clear explanation for why some patients with Parkinson¿s Disease (PD) develop psychotic symptoms. The `aberrant salience hypothesis¿ of psychosis has been influential and proposes that dopaminergic dysregulation leads to inappropriate attribution of salience to irrelevant/non-informative stimuli, facilitating the formation of hallucinations and delusions. The aim of this study is to investigate whether non-motivational salience is altered in PD patients and possibly linked to the development of psychotic symptoms.
Methods
We investigated salience processing in 14 PD patients with psychotic symptoms, 23 PD patients without psychotic symptoms and 19 healthy controls. All patients were on dopaminergic medication for their PD. We examined emotional salience using a visual oddball fMRI paradigm that has been used to investigate early stages of schizophrenia spectrum psychosis, controlling for resting cerebral blood flow as assessed with arterial spin labelling fMRI.
Results
We found significant differences between patient groups in brain responses to emotional salience. PD patients with psychotic symptoms had enhanced brain responses in the striatum, dopaminergic midbrain, hippocampus and amygdala compared to patients without psychotic symptoms. PD patients with psychotic symptoms showed significant correlations between the levels of dopaminergic drugs they were taking and BOLD signalling, as well as psychotic symptom scores.
Conclusion
Our study suggests that enhanced signalling in the striatum, dopaminergic midbrain, the hippocampus and amygdala is associated with the development of psychotic symptoms in PD, in line with that proposed in the `aberrant salience hypothesis¿ of psychosis in schizophrenia.
Revista:
EVIDENCE - BASED MENTAL HEALTH
ISSN:
1362-0347
Año:
2020
Vol.:
23
N°:
4
Págs.:
135 - 139
Introduction Although several systematic reviews (SRs)/meta-analyses (MAs) on the association between specific mental disorders and specific somatic conditions are available, an overarching evidence synthesis across mental disorders and somatic conditions is currently lacking. We will conduct an umbrella review of SRs/MAs to test: 1) the strength of the association between individual mental disorders and individual somatic conditions in children/adolescents and adults; 2) to which extent associations are specific to individual mental and somatic conditions .
Methods and analysis We will search a broad set of electronic databases and contact study authors. We will include SRs with MA or SRs reporting the effect size from individual studies on the association between a number of somatic and mental conditions (as per the International Classification of Diseases, 11th Revision). We will follow an algorithm to select only one SR or MA when more than one are available on the same association. We will rate the quality of included SRs/MAs using the AMSTAR-2 tool. We will assess to which extent mental disorders are selectively associated with specific somatic conditions or if there are transdiagnostic, across-spectra or diagnostic spectrum-specific associations between mental disorders and somatic conditions based on the Transparent, Reporting, Appraising, Numerating, Showing (TRANSD) recommendations.
Discussion The present umbrella review will shed light on the association between mental health disorders and somatic conditions, providing useful data for the care of patients with mental health disorders, in particular for early detection and intervention. This work might also add insight to the pathophysiology of mental health conditions, and contribute to the current debate on the value of a transdiagnostic approach in psychiatry.
Revista:
EUROPEAN JOURNAL OF NEUROLOGY
ISSN:
1468-1331
Año:
2020
Vol.:
27
N°:
2
Págs.:
213 - 214
Revista:
FRONTIERS IN PSYCHOLOGY
ISSN:
1664-1078
Background/objective: Adult Lower Secondary Education is an education program for basic qualifications for the labor market. Our study aimed to compare lifetime mental health problems between current Adult Lower Secondary Education students and higher Vocational Education students, as the former constitutes a highly distinct and understudied group.
Methods: Findings were based on a cross-sectional self-report survey. Lifetime relative odds of occurrence of mental disorders [i.e., psychiatric disorders typically diagnosed in adults, learning difficulties or deficit hyperactivity disorder (ADHD)] were compared between Adult Lower Secondary Education students (n = 134) and Vocational Education students (n = 149).
Results: While the frequency of mental health problems was high in both groups, psychiatric disorders typically diagnosed in adults were more common in Adult Lower Secondary Education students than among other students. Vocational Education students reported higher rates of ADHD.
Conclusion: There is a need for additional psychological resources for Adult Lower Secondary Education students, an educational level that is the last path for many to acquire a basic degree.
Revista:
ZONA HOSPITALARIA
ISSN:
2253-9034
Año:
2019
N°:
79
Págs.:
18 - 19
Artículo de divulgación científica sobre el TDAH en adultos
Revista:
CUADERNOS DE PEDAGOGIA
ISSN:
0210-0630
Año:
2019
N°:
501
Págs.:
65 - 70
Revisamos la relación entre una visión integradora del concepto de hábito y el trastorno por déficit de atención e hiperactividad (TDAH), a partir de dificultades propias de esta condición para el estudio, la accidentabilidad, la dieta y el ejercicio, o los procesos adictivos. Proponemos que muchas consecuencias del TDAH pueden entenderse como una dificultad para la creación y el mantenimiento de hábitos positivos.
Revista:
SCIENTIFIC REPORTS
ISSN:
2045-2322
Año:
2018
Vol.:
8
Págs.:
7584
Poisoning, a subtype of physical injury, is an important hazard in children and youth. Individuals with ADHD may be at higher risk of poisoning. Here, we conducted a systematic review and meta-analysis to quantify this risk. Furthermore, since physical injuries, likely share causal mechanisms with those of poisoning, we compared the relative risk of poisoning and injuries pooling studies reporting both. As per our pre-registered protocol (PROSPERO ID CRD42017079911), we searched 114 databases through November 2017. From a pool of 826 potentially relevant references, screened independently by two researchers, nine studies (84,756 individuals with and 1,398,946 without the disorder) were retained. We pooled hazard and odds ratios using Robust Variance Estimation, a meta-analytic method aimed to deal with non-independence of outcomes. We found that ADHD is associated with a significantly higher risk of poisoning (Relative Risk = 3.14, 95% Confidence Interval = 2.23 to 4.42). Results also indicated that the relative risk of poisoning is significantly higher than that of physical injuries when comparing individuals with and without ADHD (Beta coefficient = 0.686, 95% Confidence Interval = 0.166 to 1.206). These findings should inform clinical guidelines and public health programs aimed to reduce physical risks in children/adolescents with ADHD.
Revista:
NEUROSCIENCE AND BIOBEHAVIORAL REVIEWS
ISSN:
0149-7634
Año:
2018
Vol.:
84
Págs.:
63-71
A systematic review with meta-analyses was performed to: 1) quantify the association between ADHD and risk of unintentional physical injuries in children/adolescents ("risk analysis"); 2) assess the effect of ADHD medications on this risk ("medication analysis"). We searched 114 databases through June 2017. For the risk analysis, studies reporting sex-controlled odds ratios (ORs) or hazard ratios (HRs) estimating the association between ADHD and injuries were combined. Pooled ORs (28 studies, 4,055,620 individuals without and 350,938 with ADHD) and HRs (4 studies, 901,891 individuals without and 20,363 with ADHD) were 1.53 (95% CI=1.40,1.67) and 1.39 (95% CI=1.06,1.83), respectively. For the medication analysis, we meta-analysed studies that avoided the confounding-by-indication bias [four studies with a self-controlled methodology and another comparing risk over time and groups (a "difference in differences" methodology)]. The pooled effect size was 0.879 (95% CI=0.838,0.922) (13,254 individuals with ADHD). ADHD is significantly associated with an increased risk of unintentional injuries and ADHD medications have a protective effect, at least in the short term, as indicated by self-controlled studie
Revista:
ANALES DE PEDIATRIA
ISSN:
1695-4033
Año:
2018
Vol.:
88
N°:
5
Págs.:
294 - 295
Revista:
FRONTIERS IN NEUROLOGY
ISSN:
1664-2295
Año:
2017
Vol.:
8
Págs.:
156
Psychotic symptoms frequently occur in Parkinson's disease (PD), but their pathophysiology is poorly understood. According to the National Institute of Health RDoc programme, the pathophysiological basis of neuropsychiatric symptoms may be better understood in terms of dysfunction of underlying domains of neurocognition in a trans-diagnostic fashion. Abnormal cortico-striatal reward processing has been proposed as a key domain contributing to the pathogenesis of psychotic symptoms in schizophrenia. This theory has received empirical support in the study of schizophrenia spectrum disorders and preclinical models of psychosis, but has not been tested in the psychosis associated with PD. We, therefore, investigated brain responses associated with reward expectation and prediction error signaling during reinforcement learning in PD-associated psychosis. An instrumental learning task with monetary gains and losses was conducted during an fMRI study in PD patients with (n¿=¿12), or without (n¿=¿17), a history of psychotic symptoms, along with a sample of healthy controls (n¿=¿24). We conducted region of interest analyses in the ventral striatum (VS), ventromedial prefrontal and posterior cingulate cortices, and whole-brain analyses. There was reduced activation in PD patients with a history of psychosis, compared to those without, in the posterior cingulate cortex and the VS during reward anticipation (p¿<¿0.05 small volume corrected). The results suggest that cortical and striatal
Revista:
BMJ OPEN
ISSN:
2044-6055
Año:
2017
Vol.:
7
N°:
9
Págs.:
e018027
Attention-deficit hyperactivity disorder (ADHD) has been related to increased rates of unintentional injuries. However, the magnitude of the effect and to which extent variables such as sex, age or comorbidity can influence this relationship is unknown. Additionally, and importantly, it is unclear if, and to which degree, ADHD medications can decrease the number of unintentional injuries. Due to the amount of economic and social resources invested in the treatment of injuries, filling these gaps in the literature is highly relevant from a public health standpoint. Here, we present a protocol for a systematic review and meta-analysis to estimate the relationship between ADHD and unintentional injuries and assess the impact of pharmacological treatment for ADHD METHODS AND ANALYSIS: We will combine results from 114 bibliographic databases for studies relating ADHD and risk of injuries. Bibliographic searches and data extraction will be carried out independently by two researchers. The studies' risk of bias will be assessed using the Newcastle-Ottawa Scale. Articles reporting ORs or HRs of suffering an injury in ADHD compared with controls (or enough data to calculate them) will be combined using Robust Variance Estimation, a method that permits to include multiple non-independent outcomes in the analysis. All analyses will be carried out in Stata. Age, sex and comorbid conduct disorders will be considered as potential causes of variance and their effect analysed through meta-re
Revista:
EDUCACION MEDICA
ISSN:
1575-1813
Año:
2017
Vol.:
18
N°:
4
Págs.:
267 - 269
La conformación de las estructuras anatómicas es compleja en los 3 planos del espacio. Históricamente, la enseñanza de la anatomía se ha hecho a partir de representaciones bidimensionales, de modelos físicos tridimensionales o de cuerpos reales. Solo recientemente ha sido factible crear modelos anatómicos digitales tridimensionales, que pueden ser explorados en línea a través de Internet. El objetivo del presente trabajo es analizar 2 de las herramientas en línea más conocidas para la visualización anatómica (Anatomography® y BioDigital® Human), y presentar una experiencia docente de uso en el área de neurociencias. Se crearon imágenes de estructuras cerebrales animadas que se usaron en clase posteriormente, y se preguntó a los alumnos sobre su interés y utilidad. Los resultados indicaron que la utilización de este tipo de recursos es interesante por su flexibilidad, atractivo y coste.
Autores:
Segarra, N.; Metastasio, A.; Ziauddeen, H.; et al.
Revista:
NEUROPSYCHOPHARMACOLOGY
ISSN:
0893-133X
Año:
2016
Vol.:
41
N°:
8
Págs.:
2001 - 2010
Alterations in reward processes may underlie motivational and anhedonic symptoms in depression and schizophrenia. However it remains unclear whether these alterations are disorder-specific or shared, and whether they clearly relate to symptom generation or not. We studied brain responses to unexpected rewards during a simulated slot-machine game in 24 patients with depression, 21 patients with schizophrenia, and 21 healthy controls using functional magnetic resonance imaging. We investigated relationships between brain activation, task-related motivation, and questionnaire rated anhedonia. There was reduced activation in the orbitofrontal cortex, ventral striatum, inferior temporal gyrus, and occipital cortex in both depression and schizophrenia in comparison with healthy participants during receipt of unexpected reward. In the medial prefrontal cortex both patient groups showed reduced activation, with activation significantly more abnormal in schizophrenia than depression. Anterior cingulate and medial frontal cortical activation predicted task-related motivation, which in turn predicted anhedonia severity in schizophrenia. Our findings provide evidence for overlapping hypofunction in ventral striatal and orbitofrontal regions in depression and schizophrenia during unexpected reward receipt, and for a relationship between unexpected reward processing in the medial prefrontal cortex and the generation of motivational states.
Revista:
EUROPEAN NEUROPSYCHOPHARMACOLOGY
ISSN:
0924-977X
Año:
2015
Vol.:
25
N°:
6
Págs.:
817 - 827
Studies on animals and humans have demonstrated the importance of dopamine in modulating decision-making processes. In this work, we have tested dopaminergic modulation of economic decision-making and its neural correlates by administering either placebo or metoclopramide, a dopamine D2-receptor antagonist, to healthy subjects, during a functional MRI study. The decision-making task combined probability and time delay with a fixed monetary reward. For individual behavioral characterization, we used the Probability Time Trade-off (PTT) economic model, which integrates the traditional trade-offs of reward magnitude-time and reward magnitude-probability into a single measurement, thereby quantifying the subjective value of a delayed and probabilistic outcome. A regression analysis between BOLD signal and the PTT model index permitted to identify the neural substrate encoding the subjective reward-value. Behaviorally, medication reduced the rate of temporal discounting over probability, reflected in medicated subjects being more prone to postpone the reward in order to increase the outcome probability. In addition, medicated subjects showed less activity during the task in the postcentral gyrus as well as frontomedian areas, whereas there were no differences in the ventromedial orbitofrontal cortex (VMOFC) between groups when coding the subjective value. The present study demonstrates by means of behavior and imaging that dopamine modulation alters the probability-time trade-off in human economic decision-making.
Revista:
BRITISH JOURNAL OF PSYCHIATRY
ISSN:
0007-1250
Año:
2015
Vol.:
207
N°:
1
Págs.:
79 - 80
Depression and borderline personality disorder (BPD) are both thought to be accompanied by alterations in the subjective experience of environmental rewards. We evaluated responses to sweet, bitter and neutral tastes (juice, quinine and water) in 29 women with depression, 17 women with BPD and 27 female healthy controls (HC). BPD patients gave lower pleasantness and higher disgust ratings for quinine and juice compared to controls; depression patients did not differ significantly from controls. Juice disgust ratings were related to self-disgust in BPD, suggesting close links between abnormal sensory processing and self-identity in BPD.
Revista:
FRONTIERS IN PSYCHOLOGY
ISSN:
1664-1078
Año:
2015
Vol.:
6
Págs.:
1280
In the research domain framework (RDoC), dysfunctional reward expectation has been proposed to be a cross-diagnostic domain in psychiatry, which may contribute to symptoms common to various neuropsychiatric conditions, such as anhedonia or apathy/avolition. We used a modified version of the Monetary Incentive Delay (MID) paradigm to obtain functional MRI images from 22 patients with schizophrenia, 24 with depression and 21 controls. Anhedonia and other symptoms of depression, and overall positive and negative symptomatology were also measured. We hypothesized that the two clinical groups would have a reduced activity in the ventral striatum when anticipating reward (compared to anticipation of a neutral outcome) and that striatal activation would correlate with clinical measures of motivational problems and anhedonia. Results were consistent with the first hypothesis: two clusters in both the left and right ventral striatum were found to differ between the groups in reward anticipation. Post-hoc analysis showed that this was due to higher activation in the controls compared to the schizophrenia and the depression groups in the right ventral striatum, with activation differences between depression and controls also seen in the left ventral striatum. No differences were found between the two patient groups, and there were no areas of abnormal cortical activation in either group that survived correction for multiple comparisons. Reduced ventral striatal activity was related to greater anhedonia and overall depressive symptoms in the schizophrenia group, but not in the participants with depression. Findings are discussed in relation to previous literature but overall are supporting evidence of reward system dysfunction across the neuropsychiatric continuum, even if the specific clinical relevance is still not fully understood. We also discuss how the RDoC approach may help to solve some of the replication problems in psychiatric fMRI research.
Revista:
PLOS ONE
ISSN:
1932-6203
Año:
2015
Vol.:
10
N°:
7
Págs.:
e0131536
BACKGROUND:
Imaging studies help to understand the evolution of key cognitive processes related to aging, such as working memory (WM). This study aimed to test three hypotheses in older adults. First, that the brain activation pattern associated to WM processes in elderly during successful low load tasks is located in posterior sensory and associative areas; second, that the prefrontal and parietal cortex and basal ganglia should be more active during high-demand tasks; third, that cerebellar activations are related to high-demand cognitive tasks and have a specific lateralization depending on the condition.
METHODS:
We used a neuropsychological assessment with functional magnetic resonance imaging and a core N-back paradigm design that was maintained across the combination of four conditions of stimuli and two memory loads in a sample of twenty elderly subjects.
RESULTS:
During low-loads, activations were located in the visual ventral network. In high loads, there was an involvement of the basal ganglia and cerebellum in addition to the frontal and parietal cortices. Moreover, we detected an executive control role of the cerebellum in a relatively symmetric fronto-parietal network. Nevertheless, this network showed a predominantly left lateralization in parietal regions associated presumably with an overuse of verbal storage strategies. The differential activations between conditions were stimuli-dependent and were located in sensory areas.
CONCLUSION:
Successful WM processes in the elderly population are accompanied by an activation pattern that involves cerebellar regions working together with a fronto-parietal network.
Revista:
IEEE TRANSACTIONS ON MEDICAL IMAGING
ISSN:
0278-0062
Año:
2014
Vol.:
33
N°:
5
Págs.:
1044 - 1053
Repetitive and alternating lower limb movements are a specific component of human gait. Due to technical challenges, the neural mechanisms underlying such movements have not been previously studied with functional magnetic resonance imaging. In this study, we present a novel treadmill device employed to investigate the kinematics and the brain activation patterns involved in alternating and repetitive movements of the lower limbs. Once inside the scanner, 19 healthy subjects were guided by two visual cues and instructed to perform a motor task which involved repetitive and alternating movements of both lower limbs while selecting their individual comfortable amplitude on the treadmill. The device facilitated the performance of coordinated stepping while registering the concurrent lower-limb displacements, which allowed us to quantify some movement primary kinematic features such as amplitude and frequency. During stepping, significant blood oxygen level dependent signal increases were observed bilaterally in primary and secondary sensorimotor cortex, the supplementary motor area, premotor cortex, prefrontal cortex, superior and inferior parietal lobules, putamen and cerebellum, regions that are known to be involved in lower limb motor control. Brain activations related to individual adjustments during motor performance were identified in a right lateralized network including striatal, extrastriatal, and fronto-parietal areas.
Revista:
NEUROIMAGE
ISSN:
1053-8119
Año:
2013
Vol.:
83
Págs.:
646 - 657
High-resolution isotropic three-dimensional reconstructions of human brain gray and white matter structures can be characterized to quantify aspects of their shape, volume and topological complexity. In particular, methods based on fractal analysis have been applied in neuroimaging studies to quantify the structural complexity of the brain in both healthy and impaired conditions. The usefulness of such measures for characterizing individual differences in brain structure critically depends on their within-subject reproducibility in order to allow the robust detection of between-subject differences. This study analyzes key analytic parameters of three fractal-based methods that rely on the box-counting algorithm with the aim to maximize within-subject reproducibility of the fractal characterizations of different brain objects, including the pial surface, the cortical ribbon volume, the white matter volume and the gray matter/white matter boundary. Two separate datasets originating from different imaging centers were analyzed, comprising 50 subjects with three and 24 subjects with four successive scanning sessions per subject, respectively. The reproducibility of fractal measures was statistically assessed by computing their intra-class correlations. Results reveal differences between different fractal estimators and allow the identification of several parameters that are critical for high reproducibility. Highest reproducibility with intra-class correlations in the range of 0.9-0.95 is achieved with the correlation dimension. Further analyses of the fractal dimensions of parcellated cortical and subcortical gray matter regions suggest robustly estimated and region-specific patterns of individual variability. These results are valuable for defining appropriate parameter configurations when studying changes in fractal descriptors of human brain structure, for instance in studies of neurological diseases that do not allow repeated measurements or for disease-course longitudinal studies.
Revista:
JOURNAL OF ALZHEIMERS DISEASE
ISSN:
1387-2877
Año:
2013
Vol.:
33
N°:
4
Págs.:
1009 - 1019
The aim of our study was to elucidate whether specific patterns of gray matter loss were associated with apolipoprotein E epsilon 4 (APOE epsilon 4) and microtubule-associated protein tau (MAPT)-H1) genetic variants in subjects with mild cognitive impairment (MCI) at a baseline visit. Gray matter voxel-based morphometry analysis of T1 magnetic resonance imaging scans were performed in 65 amnestic-MCI subjects. MCI APOE epsilon 4 carriers compared with non-carriers showed increased brain atrophy in right hippocampus and rostral amygdala, superior and middle temporal gyrus, and right parietal operculum, including inferior frontal gyrus, inferior parietal, and supramarginal gyrus. MAPT-H1/H1 MCI carriers showed an increased bilateral atrophy in superior frontal gyri (including frontal eye fields and left prefrontal cortex) and precentral gyrus but also unilateral left atrophy in the inferior temporal gyrus and calcarine gyrus. In addition, MCI subjects carrying both APOE epsilon 4 and MAPT-H1/H1 variants showed gray matter loss in the supplementary motor area and right pre- and postcentral gyri. The effect of APOE epsilon 4 on gray matter loss in right hippocampus suggests that, at least in some AD sub-types, the neuronal vulnerability could be increased in the right hemisphere. The pattern of frontal gray matter loss observed among MCI MAPT H1/H1 carriers has also been found in other tauopathies, suggesting that MCI may share etiological factors with other tauopathies. Frontal and parietal cortex vulnerability was found when adding MAPT H1/H1 and APOE epsilon 4 effects, suggesting a synergistic effect of these variants. These results could be due to changes in APOE epsilon 4 and MAPT expression.
Revista:
PLOS ONE
ISSN:
1932-6203
Año:
2011
Vol.:
6
N°:
3
Págs.:
e17408
Decision making can be regarded as the outcome of cognitive processes leading to the selection of a course of action among several alternatives. Borrowing a central measurement from information theory, Shannon entropy, we quantified the uncertainties produced by decisions of participants within an economic decision task under different configurations of reward probability and time. These descriptors were used to obtain blood oxygen level-dependent (BOLD) signal correlates of uncertainty and two clusters codifying the Shannon entropy of task configurations were identified: a large cluster including parts of the right middle cingulate cortex (MCC) and left and right pre-supplementary motor areas (pre-SMA) and a small cluster at the left anterior thalamus. Subsequent functional connectivity analyses using the psycho-physiological interactions model identified areas involved in the functional integration of uncertainty. Results indicate that clusters mostly located at frontal and temporal cortices experienced an increased connectivity with the right MCC and left and right pre-SMA as the uncertainty was higher. Furthermore, pre-SMA was also functionally connected to a rich set of areas, most of them associative areas located at occipital and parietal lobes. This study provides a map of the human brain segregation and integration (i.e., neural substrate and functional connectivity respectively) of the uncertainty associated to an economic decision making paradigm.
Revista:
Cognitive Processing - Heidelberg
ISSN:
1612-4782
Año:
2011
Vol.:
12
N°:
2
Págs.:
183 - 186
Semantic memory is the subsystem of human memory that stores knowledge of concepts or meanings, as opposed to life-specific experiences. How humans organize semantic information remains poorly understood. In an effort to better understand this issue, we conducted a verbal fluency experiment on 200 participants with the aim of inferring and representing the conceptual storage structure of the natural category of animals as a network. This was done by formulating a statistical framework for co-occurring concepts that aims to infer significant concept-concept associations and represent them as a graph. The resulting network was analyzed and enriched by means of a missing links recovery criterion based on modularity. Both network models were compared to a thresholded co-occurrence approach. They were evaluated using a random subset of verbal fluency tests and comparing the network outcomes (linked pairs are clustering transitions and disconnected pairs are switching transitions) to the outcomes of two expert human raters. Results show that the network models proposed in this study overcome a thresholded co-occurrence approach, and their outcomes are in high agreement with human evaluations. Finally, the interplay between conceptual structure and retrieval mechanisms is discussed.
Revista:
JOURNAL OF CLINICAL AND EXPERIMENTAL NEUROPSYCHOLOGY
ISSN:
1380-3395
Año:
2010
Vol.:
33
N°:
2
Págs.:
169-175
The aim of the study was to analyze lexical access strategies in patients with multiple sclerosis (MS) and their changes over time. We studied lexical access strategies during semantic and phonemic verbal fluency tests and also confrontation naming in a 2-year prospective cohort of 45 MS patients and 20 healthy controls. At baseline, switching lexical access strategy (both in semantic and in phonemic verbal fluency tests) and confrontation naming were significantly impaired in MS patients compared with controls. After 2 years follow-up, switching score decreased, and cluster size increased over time in semantic verbal fluency tasks, suggesting a failure in the retrieval of lexical information rather than an impairment of the lexical pool. In conclusion, these findings underline the significant presence of lexical access problems in patients with MS and could point out their key role in the alterations of high-level communications abilities in MS.
Revista:
THE EUROPEAN NEUROLOGICAL JOURNAL
ISSN:
2041-8000
Año:
2010
Vol.:
2
N°:
1
Págs.:
11
Background: Language is frequently impaired in multiple sclerosis (MS) in which, in addition to dysarthria and loss of fluency, other language deficits might affect patients and impinge on their quality of life. Aims: The aim of this study was to examine spontaneous language production in MS and to assess its relationship with cognitive deterioration. Methods: Sixteen MS patients and 10 healthy control subjects matched by age and education were studied. Participants were instructed to talk about their life for half an hour. After the transcription of the texts, several parameters were measured, including the number of words, mean and maximum sentence length, lexical density, and number of words produced by the evaluator to maintain conversation. The cognitive impairment of the patients was classified using the Brief Repeatable Battery—Neuropsychology (BRB-N). Results: A decrease in the number of words and in sentence length was detected, as well as an increase in the interventions by the neuropsychologist in patients with MS. Patients with cognitive impairment performed worse in most parameters than control subjects and patients with no cognitive impairment. In addition, the number of words spoken by patients and the interventions by the evaluator were correlated with performance in the Paced Auditory Serial Addition Task and phonetic fluency tests of the BRB-N. Moreover, lexical density was correlated with all cognitive domains. Conclusions: MS patients have structural problems in language production, and flexibility when constructing a complex discourse is also impaired, with both difficulties being related to cognitive impairment, particularly with executive dysfunction. Cognitive impairment is also related to impoverished lexical access.
Revista:
International Journal of Bifurcation and Chaos
ISSN:
0218-1274
Año:
2010
Vol.:
20
N°:
3
Págs.:
913 - 922
Semantic memory is the subsystem of human memory that stores knowledge of concepts or meanings, as opposed to life specific experiences. The organization of concepts within semantic memory can be understood as a semantic network, where the concepts (nodes) are associated (linked) to others depending on perceptions, similarities, etc. Lexical access is the complementary part of this system and allows the retrieval of such organized knowledge. While conceptual information is stored under certain underlying organization (and thus gives rise to a specific topology), it is crucial to have an accurate access to any of the information units, e. g. the concepts, for efficiently retrieving semantic information for real-time need. An example of an information retrieval process occurs in verbal fluency tasks, and it is known to involve two different mechanisms: "clustering", or generating words within a subcategory, and, when a subcategory is exhausted, "switching" to a new subcategory. We extended this approach to random-walking on a network (clustering) in combination to jumping (switching) to any node with certain probability and derived its analytical expression based on Markov chains. Results show that this dual mechanism contributes to optimize the exploration of different network models in terms of the mean first passage time. Additionally, this cognitive inspired dual mechanism opens a new framework to better understand and evaluate exploration, propagation and transport phenomena in other complex systems where switching-like phenomena are feasible.
