ADHD affects working memory (WM) and other executive functions (EFs) and thereby negatively impacts school performance, clinical symptoms and functional impairment. The main aim of this study was to analyse the efficacy of computerized WM training (CWMT) on EF rating scales. A secondary objective was to assess its efficacy on performance-based measures of EF (PBMEF), learning, clinical symptoms and functional impairment. 66 children with combined-type ADHD between 7 and 12 years of age from the Child and Adolescent Psychiatric Unit (Spain) were included in this randomized, double-blind, placebo-controlled, parallel-group clinical trial. The participants were randomized (1:1) to an experimental group (EG) (CWMT) (n = 36) or a control group (CG) (placebo training). Assessments were conducted at baseline (T0), 1-2 weeks (T1), and 6 months post-intervention (T2) with the administration of EF rating scales, PBMEF, measures of academic achievement, and questionnaires regarding clinical symptoms and functional impairment. Participants, parents, teachers and professionals who performed the cognitive assessments were blinded. Adjusted multiple linear regression analysis showed significant improvements in EF scales-parent version, from T1 to T2, on the metacognition index [p = 0.03, d' = -0.78 (95 % CI -1.28 to -0.27)] and on WM (also significant at T2-T0) and plan/organize subscales. Significant improvements were also noted in EF scales-teacher version, from T0 to T1 and T2, on the metacognitive index [p = 0.05, d' = -0.37 (95 % CI -0.86 to 0.12) T1-T0, p = 0.02, d' = -0.81 (95 % CI -1.31 to -0.30) T2-T0] and on the initiate, WM, monitor and shift subscales. There were also significant improvements in PBMEF, ADHD symptoms, and functional impairment. CWMT had a significant impact on ADHD deficits by achieving long-term far-transfer effects.

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Background: Conduct disorder (CD) rarely occurs alone but is typically accompanied by comorbid psychiatric disorders, which complicates the clinical presentation and treatment of affected youths. The aim of this study was to investigate sex differences in comorbidity pattern in CD and to systematically explore the 'gender paradox' and 'delayed-onset pathway' hypotheses of female CD. Methods: As part of the FemNAT-CD multisite study, semistructured clinical interviews and rating scales were used to perform a comprehensive phenotypic characterization of 454 girls and 295 boys with CD (9-18 years), compared to 864 sex-and age-matched typically developing controls. Results: Girls with CD exhibited higher rates of current major depression, anxiety disorders, post-traumatic stress disorder and borderline personality disorder, whereas boys with CD had higher rates of current attention-deficit/ hyperactivity disorder. In line with the 'gender paradox' hypothesis, relative to boys, girls with CD showed significantly more lifetime psychiatric comorbidities (incl. Alcohol Use Disorder), which were accompanied by more severe CD symptoms. Female and male youths with CD also differed significantly in their CD symptom profiles and distribution of age-of-onset subtypes of CD (i.e. fewer girls with childhood-onset CD). In line with the 'delayed-onset pathway' hypothesis, girls with adolescent-onset CD showed similar levels of dimensional psychopathology like boys with childhood-onset CD, while boys with adolescent-onset CD had the lowest levels of internalizing psychopathology. Conclusions: Within the largest study of CD in girls performed to date, we found compelling evidence for sex differences in comorbidity patterns and clinical presentation of CD. Our findings further support aspects of the 'gender paradox' and 'delayed-onset pathway' hypotheses by showing that girls with CD had higher rates of comorbid lifetime mental disorders and functional impairments, and they usually developed CD during adolescence. These novel data on sex-specific clinical profiles of CD will be critical in informing intervention and prevention programmes.