showed that in children and adolescent patients with ADHD, GM volumes of frontal and temporal lobes, caudate, and cerebellum were negatively correlated with the overall score of illness severity, and particularly, attention problems 31. How these regions GM reduction links to inattention symptom or cognitive deficits is not entirely clear. Studies of adult patients with ADHD, relatively sparse compared to children, have shown GM alterations in less but more specific brain regions, with the cerebellum and frontal cortex 30, 32, 33 being reported more consistently than subcortical regions 25, 34, 35. Studies of children and/or adolescents have reported GM reduction in widespread brain regions, while the most common effects are in the subcortical regions 25, 26, 27 and cerebellum 28, followed by regions in the frontal, parietal, temporal cortex 29, 30, 31. The focus of this study is to investigate gray matter (GM) variation in relation to attention and working memory deficits in both adolescents and adults with ADHD 23, 24. Yet, the underlying neural mechanisms for the different presentations of children and adults with ADHD, as well as consistent presentations, remain elusive. Working memory deficits in ADHD have been consistently reported for both adolescents and adults 14, 20, 21, 22. Children with ADHD were affected in more diverse cognitive domains 12, 13, 14, 15, 16, 17, 18, 19 than adults, whose working memory impairments were most frequently documented 16, 20. Adult ADHD had a higher rate of comorbidity than children ADHD 10, complicating diagnosis 11. For instance, adults with ADHD were more affected by inattention than hyperactivity 7, while children presented symptoms in both inattention and hyperactivity domains. Predominant features of adults with ADHD also differ from that of children with ADHD. It is a highly heterogeneous disorder with three clinical presentations recognized in DSM-5 edition 5, and diverse neurocognitive impairments 6, 7, comorbid disorders, etc 6, 7, 8, 9. Recently ADHD persistence into adulthood has been observed in 15–50% of cases 1, 2, depending on whether or not counting partial remissions 3, 4. Our findings suggest although the gray matter reduction of these regions may not be indicative of persistency of ADHD, their persistent associations with inattention or working memory indicate an important role of these regions in the mechanism of persistence or remission of the disorder.Īttention-deficit/hyperactivity disorder (ADHD) is a childhood-onset neuropsychiatric disorder characterized by inattention, and/or hyperactivity and impulsivity. All these components presented a significant or nominal level of gray matter reduction for ADHD participants in adolescents, but only one showed nominal reduction in adults. One component in bilateral cerebellar tonsil and culmen identified in adults and one component in left cerebellar region identified in adolescents were significantly associated with inattention in both cohorts. Two components in the inferior, middle/superior frontal regions identified in adults and one component in the insula and inferior frontal region identified in adolescents were significantly associated with working memory in both cohorts. Then, we identified gray matter networks associated with inattention or working memory in each cohort, and projected them onto the other cohort for comparison. Independent component analysis was applied to the gray matter of each cohort, separately, to extract cohort-inherent networks. Two cohorts both presented significant attention and working memory deficits in individuals with ADHD. In this study, we investigated gray matter of two cohorts, 486 adults and 508 adolescents, each including participants from ADHD and healthy controls families. How neuronal underpinnings of deficits differ across adolescence and adulthood is not clear. Working memory and attention deficits have been reported to persist from childhood to adulthood. Attention-deficit/hyperactivity disorder (ADHD) is a childhood-onset neuropsychiatric disorder and may persist into adulthood.
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