Padrões de sono e Transtorno do Déficit de Atenção e Hiperatividade (TDAH): perspectivas observacional e genética

Abstract

Despite the high comorbidity between Attention Deficit Hyperactivity Disorder (ADHD) and sleep problems, short sleep duration and circadian dysfunctions reported in the literature, it is not yet clear whether these sleep patterns are side effects or a risk factor for ADHD. Few studies use longitudinal design and analysis to study the temporal relationship of this relationship. Furthermore, studies that have sought to understand the genetic relationship between the two conditions have used the candidate-gene strategy and the results are restricted to a few genetic markers. This thesis aims at investigating the relationship between sleep patterns and ADHD through both observational and genetic approaches. The first study explored the association between sleep duration and sleep problems in the first years of life (1,2 and 4 years) and ADHD at 11 years of age in the 2004 Pelotas birth cohort. Based on the recent discovery of associated genetic markers provided by Genome Wide Association Studies for the phenotypes evaluated in this thesis, the second article sought to assess the genetic contribution and causal relationship between sleep/circadian cycle and ADHD. The third article aimed to evaluate the mediating effect of executive functions related to attention in the relationship between early sleep problems and ADHD in adolescence. Finally, the volume has an additional article, which aimed to investigate the association between markers of the CLOCK gene and ADHD in a clinical sample of children / adolescents. Considering all the findings, it can be concluded that sleep problems, especially those related to chronic sleep deprivation, are predictors of ADHD, and have components of shared genetics and mechanisms related to neuroactivity functions in the process of signaling. Still, it was identified that executive functions related to attention would not mediate the effect of early sleep problems in ADHD.