Computerized Cognitive Training for ADHD as an Add-On Treatment to Stimulants: A Randomized Clinical Trial.

Objective: Computerized cognitive training (CCT) as add-on treatment to stimulants for ADHD core symptoms is scarcely investigated. The purpose of this study is to assess the effect of CCT in a randomized controlled clinical trial for ADHD in children and adolescents treated with stimulants. Method: Fifty-three participants aged 6 to 13 years receiving stimulant treatment and presenting ADHD residual symptoms were randomized either to a CCT (n = 29) or to a controlled nonactive condition (n = 24) for four sessions/week during 12 weeks. The main outcome measure was inattentive symptoms assessed using the Swanson, Nolan, and Pelham-IV (SNAP-IV) Scale. Secondary outcomes include, among others, hyperactive/impulsive symptoms and cognitive tests. Results: There were neither significant group differences on ADHD-inattentive symptoms after the intervention nor on both ADHD-hyperactivity/impulsivity symptoms and cognitive measures. Conclusion: Our study does not provide evidence for the benefits of cognitive training over nonactive training on core ADHD symptoms in medicated ADHD children and adolescents.

Streptococcus mutans and Actinomyces naeslundii Interaction in Dual-Species Biofilm.

The study of bacterial interaction between Streptococcus mutans and Actinomyces naeslundii may disclose important features of biofilm interspecies relationships. The aim of this study was to characterize-with an emphasis on biofilm formation and composition and metabolic activity-single- and dual-species biofilms of S. mutans or A. naeslundii, and to use a drip flow reactor (DFR) to evaluate biofilm stress responses to 0.2% chlorhexidine diacetate (CHX). Single- and dual-species biofilms were grown for 24 h. The following factors were evaluated: cell viability, biomass and total proteins in the extracellular matrix, 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide-"XTT"-reduction and lactic acid production. To evaluate stress response, biofilms were grown in DFR. Biofilms were treated with CHX or 0.9% sodium chloride (NaCl; control). Biofilms were plated for viability assessment. Confocal laser-scanning microscopy (CLSM) was also performed. Data analysis was carried out at 5% significance level. S. mutans viability and lactic acid production in dual-species biofilms were significantly reduced. S. mutans showed a higher resistance to CHX in dual-species biofilms. Total protein content, biomass and XTT reduction showed no significant differences between single- and dual-species biofilms. CLSM images showed the formation of large clusters in dual-species biofilms. In conclusion, dual-species biofilms reduced S. mutans viability and lactic acid production and increased S. mutans' resistance to chlorhexidine.

Effects of computerized cognitive training as add-on treatment to stimulants in ADHD: a pilot fMRI study.

The neurofunctional effects of Cognitive training (CT) are poorly understood. Our main objective was to assess fMRI brain activation patterns in children with ADHD who received CT as an add-on treatment to stimulant medication. We included twenty children with ADHD from a clinical trial of stimulant medication and CT (10 in medication + CT and 10 in medication + non-active training). Between-group differences were assessed in performance and in brain activation during 3 fMRI paradigms of working memory (N-back: 0-back, 1-back, 2-back, 3-back), sustained attention (Sustained Attention Task - SAT: 2 s, 5 s and 8 s delays) and inhibitory control (Go/No-Go). We found significant group x time x condition interactions in working memory (WM) and sustained attention on brain activation. In N-back, decreases were observed in the BOLD signal change from baseline to endpoint with increasing WM load in the right insula, right putamen, left thalamus and left pallidum in the CT compared to the non-active group; in SAT - increases in the BOLD signal change from baseline to endpoint with increasing delays were observed in bilateral precuneus, right insula, bilateral associative visual cortex and angular gyrus, right middle temporal, precentral, postcentral, superior frontal and middle frontal gyri in the CT compared to the non-active group. CT in ADHD was associated with changes in activation in task-relevant parietal and striato-limbic regions of sustained attention and working memory. Changes in brain activity may precede behavioral performance modifications in working memory and sustained attention, but not in inhibitory control.