Subcortico-Cortical Dysconnectivity in ADHD: A Voxel-Wise Mega-Analysis Across Multiple Cohorts.

OBJECTIVE: A large body of functional MRI research has examined a potential role for subcortico-cortical loops in the pathogenesis of attention deficit hyperactivity disorder (ADHD), but has produced inconsistent findings. The authors performed a mega-analysis of six neuroimaging data sets to examine associations between ADHD diagnosis and traits and subcortico-cortical connectivity. METHODS: Group differences were examined in the functional connectivity of four subcortical seeds in 1,696 youths with ADHD diagnoses (66.39% males; mean age, 10.83 years [SD=2.17]) and 6,737 unaffected control subjects (47.05% males; mean age, 10.33 years [SD=1.30]). The authors examined associations between functional connectivity and ADHD traits (total N=9,890; 50.3% males; mean age, 10.77 years [SD=1.96]). Sensitivity analyses were used to examine specificity relative to commonly comorbid internalizing and non-ADHD externalizing problems. The authors further examined results within motion-matched subsamples, and after adjusting for estimated intelligence. RESULTS: In the group comparison, youths with ADHD showed greater connectivity between striatal seeds and temporal, fronto-insular, and supplementary motor regions, as well as between the amygdala and dorsal anterior cingulate cortex, compared with control subjects. Similar findings emerged when ADHD traits were considered and when alternative seed definitions were adopted. Dominant associations centered on the connectivity of the caudate bilaterally. Findings were not driven by in-scanner motion and were not shared with commonly comorbid internalizing and externalizing problems. Effect sizes were small (largest peak d, 0.15). CONCLUSIONS: The findings from this large-scale mega-analysis support established links with subcortico-cortical circuits, which were robust to potential confounders. However, effect sizes were small, and it seems likely that resting-state subcortico-cortical connectivity can capture only a fraction of the complex pathophysiology of ADHD.

Direct formation of copper nanoparticles from atoms at graphitic step edges lowers overpotential and improves selectivity of electrocatalytic CO2 reduction.

A key strategy for minimizing our reliance on precious metals is to increase the fraction of surface atoms and improve the metal-support interface. In this work, we employ a solvent/ligand/counterion-free method to deposit copper in the atomic form directly onto a nanotextured surface of graphitized carbon nanofibers (GNFs). Our results demonstrate that under these conditions, copper atoms coalesce into nanoparticles securely anchored to the graphitic step edges, limiting their growth to 2-5 nm. The resultant hybrid Cu/GNF material displays high selectivity in the CO2 reduction reaction (CO2RR) for formate production with a faradaic efficiency of ~94% at -0.38 V vs RHE and a high turnover frequency of 2.78 × 106 h-1. The Cu nanoparticles adhered to the graphitic step edges significantly enhance electron transfer to CO2. Long-term CO2RR tests coupled with atomic-scale elucidation of changes in Cu/GNF reveal nanoparticles coarsening, and a simultaneous increase in the fraction of single Cu atoms. These changes in the catalyst structure make the onset of the CO2 reduction potential more negative, leading to less formate production at -0.38 V vs RHE, correlating with a less efficient competition of CO2 with H2O for adsorption on single Cu atoms on the graphitic surfaces, revealed by density functional theory calculations.

Exposure and response prevention versus stress management training for adults and adolescents with obsessive compulsive disorder: A randomized clinical trial.

OBJECTIVE: Though exposure and response prevention (ERP) is a well-proven treatment for OCD across the lifespan, prior RCTs have not studied adolescent and adult patients with the same ERP protocol relative to an active comparator that controls for non-specific effects of treatment. This approach assesses differences in the effect of OCD-specific exposures in affected adolescents and adults and in response to ERP compared to a stress-management control therapy (SMT). METHODS: This assessor-blinded, parallel, 2-arm, randomized, ambulatory clinical superiority trial randomized adolescents (aged 12-18) and adults (24-46) with OCD (N = 126) to 12 weekly sessions of ERP or SMT. OCD severity was measured before, during and after treatment using the child or adult version of the Yale-Brown Obsessive Compulsive Scale (C/Y-BOCS), depending on participant age. We predicted that ERP would produce greater improvement in OCD symptoms than SMT and that there would be no significant post-treatment differences across age groups. RESULTS: ERP (n = 63) produced significantly greater improvements on C/Y-BOCS scores at post-treatment than SMT (n = 63) (Effect size = -0.72, CI = -0.52 to -0.91, p < .001). ERP also produced more treatment responders (ERP = 86%, SMT = 32%; χ2 = 46.37, p < .001) and remitters than SMT (ERP = 39%, SMT = 7%; χ2 = 16.14, p < .001). Finally, there were no statistically significant post-treatment differences in C/Y-BOCS scores between adolescents and adults assigned to ERP. CONCLUSION: A single ERP protocol is superior to SMT in treating both adolescents and adults with OCD. OCD-specific therapy is necessary across the lifespan for optimal outcomes in this highly disabling disorder, though non-specific treatments like SMT are still all-too-commonly provided.