Medicina
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Attention-deficit/hyperactivity disorder (ADHD) has been the focus of magnetic resonance imaging studies for more than 30 years, with more than 2200 articles listed in PubMed. Nevertheless, the brain substrates of ADHD remain poorly understood. This reflects the crisis of replicability across nearly all scientific endeavors, deriving from factors such as small sample sizes combined with a proliferation in analytical approaches, yielding high rates of false positive results. ⋯ Adolescent Behavior & Cognitive Developm ent Study (ABCD). Both embrace the culture of open science, and are beginning to yield credible findings, despite being limited initially to cross-sectional analyses. As the field continues to mature, these and other ongoing longitudinal large-scale studies are poised to transform our understanding of the pathophysiology of ADHD to bring closer the day when neuroimaging can contribute to clinical utility.
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This study aims to contribute to a better understanding of attention deficit hyperactivity disorder (ADHD) by comprehensively examining the relationship between two of the main cognitive deficits of the disorder (attention and inhibitory control), symptomatology (inattention and hyperactivity/impulsivity) and functional impairment in 85 children and adolescents with ADHD without other comorbid disorders. We found, independent of general intellectual functioning and age, that i) greater attentional and inhibitory deficits predicted greater severity of ADHD symptoms, ii) greater attentional and inhibitory deficits predicted greater functional impairment, but not in a direct way but through symptoms, and iii) greater symptomatic severity predicted greater functional impairment. Beginning to explore and understand the complexity of ADHD is key to advance our knowledge of the disorder and for correct clinical decision making.
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Modern neuroscience addresses the problem of the global functioning of the brain in order to understand the neurobiological processes that underlie mental functions, and especially, consciousness. Brain activity is based on the exchange of information between neurons through contacts or synapses. Neurons form networks of connection between them (circuits), which are dedicated to processing a specific type of information (visual, auditory, motor ...). ⋯ The question about whether knowledge of an individual's connectome would allow us to predict his or her behavior seems to have no clear answer yet, because we do not know the physical parameters that link the complexity of the brain's connections with the appearance of mental functions and consciousness. At the moment, it seems that the complex and unpredictable behavior is not the simple result of linear processes of neuronal interaction. Uncertainty prevails over determinism, which opens the door to the possibility of a quantum mechanism to explain consciousness.
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Autism is a neurobiological developmental disorder characterized by poor social interaction and communication, narrow interests, and stereotyped behaviors. It has been associated with disorders of synaptogenesis and multiple etiologies. ⋯ We analyze how DNA methylation disorders, histone modification, remodeling and chromosomal regulation mediated by non-coding RNA are related to various genetic syndromes such as fragile X, Rett, Pathias Mecp2, Phelam McDermid, prenatal toxins such as alcohol, valproic. acid, cannabis, and environmental toxins such as maternal stress, all associated with a higher prevalence of autism. In conclusion: the recognition of these mechanisms opens up new possibilities for prevention and it is likely that, in genetic entities, it will allow the development of specific treatments with modifications tailored to each entity.
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The scientific concept of High Intellectual Ability (HIA) is expanded attending the question of discrepancy between the high cognitive potential and the low performance of some people with HIA. The study of the pathways and conditioning factors that lead to low performance is necessary in order to facilitate the development and optimal expression of high potential. The role of executive and metacognitive regulation of high intellectual resources is highlighted, in interaction with other endogenous and exogenous modulators. ⋯ The executive, metacognitive and perfectionism measures obtained in a sample of n = 140 schoolchildren, diagnosed as HIA, are statistically analyzed using Structural Equation Models. Two relational models are obtained: one indicating that executive function influences metacognition, and the other indicates that perfectionism influences executive functioning. The need for more concrete analyses of the direct, indirect or total influence among these regulation constructs is concluded and discussed, with derivations for the need of effective measures that guide the optimal expression of HIA, preserving personal well-being.