Methylphenidate is more effective to improve inhibitory control and working memory compared to tDCS in children and adolescents with attention deficit/hyperactivity disorder: a proof-of-concept study.

Introduction: Attention-deficit/hyperactivity disorder (ADHD) is characterized by an inappropriate, pervasive and persistent pattern of inattention, hyperactivity, and/or impulsivity and associated with substantial functional impairment. Despite considerable advances in the understanding and management of ADHD, some patients do not respond well to methylphenidate (MPH), the first-choice pharmacological treatment. Over the past decades, among non-invasive brain stimulation techniques, transcranial direct current stimulation (tDCS) has proven to be an effective and safe technique to improve behavior and cognition in children with neurodevelopmental disorders, including ADHD, by modifying cortical excitability. However, the effect of tDCS has never been directly compared with that of the MPH. The present randomized sham-controlled trial evaluated the effect of a single session of anodal tDCS compared with the administration of a single dose of MPH in children and adolescents with ADHD. Methods: After completing baseline assessment (T0), 26 children and adolescents with ADHD were exposed to 3 conditions with a 24-h interval-sessions: (A) a single session of anodal tDCS over the left dorsolateral prefrontal cortex (DLPFC); (B) a single session of sham tDCS over the left DLPFC; (C) a single dose of MPH. Results: Our results showed that after administering a single dose of MPH, children and adolescents with ADHD improved inhibitory control and visual-spatial WM compared with baseline, anodal, and sham tDCS. However, a single session of active tDCS over the left DLPFC was not effective compared with either baseline or sham tDCS. Discussion: In conclusion, our protocol in ADHD involving a single tDCS session did not demonstrate consistent improvements in neurocognitive features compared with baseline, sham tDCS, or single MPH administration. Different protocols need to be developed to further test the effectiveness of tDCS in improving ADHD symptoms.

Age-related clinical characteristics of children and adolescents with ADHD.

Introduction: Attention deficit hyperactivity disorder (ADHD) has been associated with difficulties in regulating aversion states, high functional impairment, and a high risk of psychopathology across the lifespan. ADHD is clinically heterogeneous, with a wide spectrum of severity and associated symptoms. Clinical characteristics need to be carefully defined in different periods of life as ADHD course, symptoms, and comorbidities may fluctuate and change over time. Adolescence usually represents the transition from primary to secondary education, with a qualitative and quantitative change in environmental and functional demands, thus driving symptoms' change. Methods: In order to characterize age-related clinical features of children (<11 years) and adolescents (≥11 years) with ADHD, we conducted a naturalistic study on 750 children and adolescents assessed for ADHD at our Neuropsychiatry Unit over the course of 3 years (2018-2020). Results: We found that ADHD symptoms were significantly higher in children than adolescents. More importantly, we found worse global functioning, lower adaptive skills, higher levels of anxiety and depressive symptoms, somatic complaints, emotional dysregulation, social problems, and aggression in adolescents, despite a lower severity of ADHD-specific symptoms. Conclusion: These results should be confirmed in longitudinal observational studies of adequate sample size in order to reliably describe a potential course characterized by worsening of functioning, reduction in ADHD-specific symptoms and increase in general psychopathology during the transition from childhood to adolescence.

Later onset of Childhood Disintegrative Disorder (CDD): a case report.

Childhood Disintegrative Disorder (CDD) is a rare condition characterized by regression of developmental and behavioral functioning after a period of apparently normal development, with an age of onset around 4 years. CDD is not included within the latest edition of the Diagnostic and Statistical Manual of Mental Disorders. We present a case report of an 11-year-old male who achieved normal development for up to 7 years followed by a deterioration of previously acquired linguistic, intellectual, and social skills. Following treatment with lithium carbonate combined with risperidone, the patient experienced a reduction in irritability and aggression. CDD is a rare condition; therefore, the data presented may be useful to investigate its characteristics of the onset, to improve the understanding of the aspects of differentiation from the Autism Spectrum Disorder and finally to propose the possibility of treatment.

Sleep Disturbances in Children with Attentional Deficit Hyperactivity Disorder and Specific Learning Disorders.

Sleep disturbances may be a significant source of distress for children with neurodevelopmental disorders, and consequently also for their families. Crucially, sleep disturbances might be influenced by comorbidity. Attention deficit hyperactivity disorder (ADHD) and specific learning disorder (SLD) often co-occur, and consequently, investigating sleep disturbances in children with comorbidity of ADHD and SLD is essential. Our study aimed at detecting sleep difficulties in a group of 74 children with ADHD, 78 children with SLD, and 76 children with ADHD and SLD by using the Sleep Disturbances Scale for Children. The results showed that sleep difficulties emerge more clearly in children with comorbid ADHD and SLD compared to children with only ADHD or SLD. These sleep difficulties were not due to differences in ages and behavioral/emotional problems. In conclusion, evaluating sleep disturbances is important when assessing and managing children with ADHD, SLD, and particularly with the two comorbid conditions, to better understand their difficulties and develop tailored interventions.

Comparing the Effect of Methylphenidate and Anodal tDCS on Inhibitory Control and Working-Memory in Children and Adolescents with Attention Deficit/Hyperactivity Disorder: A Study Protocol for a Randomized, within-Subject Trial.

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterized by inappropriate levels of attention, hyperactivity, and impulsivity that interfere with individual functioning. The international guidelines recommend targeting ADHD-related neurochemical brain abnormalities by intervening via drug treatment, such as methylphenidate (MPH), as first choice. Drug treatments are usually associated with a huge amount of cost for families and the healthcare system, suspension for low compliance, poor long-term efficacy, and side effects. Transcranial direct current stimulation (tDCS) has been suggested as a possible noninvasive means to safely manipulate brain activity and, in turn, improve behavior and cognition in developmental ages. Several studies have shown that tDCS has the potential to improve ADHD-related cognitive deficits, but the effect of tDCS compared with MPH has never been evaluated. The aim of the present within-subject, sham-controlled, randomized proof-of-concept study is to demonstrate the positive effect of one-session anodal tDCS analogous to the MPH drug on inhibitory control and working memory in children and adolescents with ADHD. We strongly believe that this study protocol will serve to accelerate research into low-cost, drug-free, feasible interventions for ADHD.

Clinical characteristics of children and adolescents with ADHD with or without methylphenidate prescription at their first diagnostic assessment.

Attention Deficit/Hyperactivity Disorder (ADHD) is the most prevalent neurodevelopmental disorder diagnosed in the scholar age. It is associated with significant impairment in global functioning, and in moderate/severe presentations the outcome is critically dependent on pharmacological optimization of the multi-modal treatment. Methylphenidate (MPH) is the first-choice pharmacological treatment in children and adolescents with ADHD, with substantial evidence of significant efficacy and effectiveness on global functioning and symptoms' severity. There is some evidence supporting a few clinical and socio-demographic variables as predictors of pharmacological treatment prescription in children with ADHD independently of ADHD symptoms severity. However, it is warranted to investigate clinical and general psychopathological characteristics potentially associated with negative outcomes and the need for pharmacological treatment to inform appropriate prescription strategies. In this context, we compared 268 children and adolescents who were prescribed MPH (ADHD/MPH) for the first time after their first diagnostic assessment at our center, and 444 children and adolescents with ADHD (ADHD/noMPH) who were recommended non-pharmacological evidence-based interventions alone. ADHD/MPH group had higher severity of non-ADHD psychopathological symptoms compared to the ADHD/noMPH group, as documented by higher scores on the Child Behavior Checklist (CBCL) subscales, higher severity of ADHD symptoms, lower average IQ and lower adaptive levels independently of IQ. More specifically, beside externalizing symptoms, also internalizing symptoms were significantly higher in the ADHD/MPH group. The presence of significant non-ADHD psychopathology should be considered as a clinical factor associated with the need for MPH prescription in children and adolescents with ADHD.

Moderators and Other Predictors of Methylphenidate Response in Children and Adolescents with ADHD.

Methylphenidate (MPH) is the treatment of first choice for developmental ADHD. To date, no reliable method to predict how patients will respond to MPH exists and conflicting results are reported on clinical characteristics of responders. The present study aims to give a more precise characterization of the patients who will respond best to MPH to help clinicians in defining the treatment plan. Age, neuropsychological functioning (i.e., attention and working memory), and behavioral/emotional symptoms of 48 drug-naïve children and adolescents with ADHD (42 boys and 6 girls, age-range 6-16 years, mean age 10.5 ± 2.5 years, mean IQ 101.3 ± 11.2) were studied to assess how these different characteristics affected a single-dose MPH response. Four hierarchical linear regression models were used to explore whether age, neuropsychological measures at baseline, and behavioral/emotional symptoms could predict attention and working memory measures after a single-dose MPH administration. We found that improvement in attention and working memory was predicted by age, neuropsychological measures at baseline, and severity of ADHD symptoms. No behavioral and emotional symptoms predicted single-dose MPH response with the exception of conduct symptoms.

Gender-Related Clinical Characteristics in Children and Adolescents with ADHD.

Attention Deficit/Hyperactivity Disorder (ADHD) is the most frequently diagnosed neurodevelopmental disorder in school-age children, and it is usually associated with a significant impairment in global functioning. Traditionally, boys with ADHD are more likely to be referred for clinical assessments due to a higher prevalence of externalizing symptoms. However, as regards gender-related differential clinical characteristics between boys and girls with ADHD, further investigation is warranted in light of conflicting results found in currently available literature. In fact, a more precise clinical characterization could help increase appropriate diagnoses and treatment planning. In this context, we carried out a retrospective observational study on 715 children and adolescents diagnosed with ADHD from 2018 to 2020 at our center, in order to describe their gender-related clinical characteristics. Boys displayed higher average IQs, but they were comparable to girls in functional impairments and adaptive skills. Girls displayed higher scores on the Attention Problems subscale of the CBCL 6-18 and on several CPRS-R:L subscales, suggesting higher general ADHD symptom severity. Boys showed higher scores on CBCL 6-18 subscales, such as withdrawn/depressed, internalizing, and obsessive-compulsive problems. In conclusion, girls showed more severe ADHD features and lower IQ in clinically referred settings, while boys showed more internalizing problems and obsessive-compulsive symptoms.

Implicit and Explicit Memory in Youths with High-Functioning Autism Spectrum Disorder: A Case-Control Study.

Individuals with autism spectrum disorder (ASD) usually manifest heterogeneous impairments in their higher cognitive functions, including their implicit memory (IM) and explicit memory (EM). However, the findings on IM and EM in youths with ASD remain debated. The aim of this study was to clarify such conflicting results by examining IM and EM using two comparable versions of the Serial Reaction Time Task (SRTT) in the same group of children and adolescents with ASD. Twenty-five youths with high-functioning ASD and 29 age-matched and IQ-matched typically developing youths undertook both tasks. The ability to implicitly learn the temporal sequence of events across the blocks in the SRTT was intact in the youths with ASD. When they were tested for EM, the participants with ASD did not experience a significant reduction in their reaction times during the blocks with the previously learned sequence, suggesting an impairment in EM. Moreover, the participants with ASD were less accurate and made more omissions than the controls in the EM task. The implications of these findings for the establishment of tailored educational programs for children with high-functioning ASD are discussed.

Cross-sectional investigation of insulin resistance in youths with autism spectrum disorder. Any role for reduced brain glucose metabolism?

The autism spectrum disorder (ASD) is an etiologically heterogeneous disorder. Dysfunctions of the intermediate metabolism have been described in some patients. We speculate these metabolic abnormalities are associated with brain insulin resistance (IR), i.e., the reduced glucose metabolism at the level of the nervous central system. The Homeostasis model assessment of insulin resistance (HOMA-IR) is very often used in population studies as estimate of peripheral IR and it has been recently recognized as proxy of brain IR. We investigated HOMA-IR in 60 ASD patients aged 4-18 years and 240 healthy controls, also aged 4-18 years, but unmatched for age, sex, body weight, or body mass index (BMI). At multivariable linear regression model, the HOMA-IR was 0.31 unit higher in ASD individuals than in controls, after having adjusted for sex, age, BMI z-score category, and lipids that are factors known to influence HOMA-IR. Findings of this preliminary study suggest it is worth investigating brain glucose metabolism in larger population of patients with ASD by using gold standard technique. The recognition of a reduced glucose metabolism in some areas of the brain as marker of autism might have tremendous impact on our understanding of the pathogenic mechanisms of the disease and in terms of public health.

Memory Deficits in Children with Developmental Dyslexia: A Reading-Level and Chronological-Age Matched Design.

Developmental Dyslexia (DD) is considered a multifactorial deficit. Among the neurocognitive impairments identified in DD, it has been found that memory plays a particularly important role in reading and learning. The present study aims to investigate whether short-term memory (STM) and long-term memory (LTM) deficits could be related to poor reading experience or could be causal factors in DD. To verify that memory deficits in DD did not simply reflect differences in reading experience, 16 children with DD were not only compared to 16 chronological age-matched children (CA) but also to 16 reading level-matched children (RL) in verbal, visual-object, and visual-spatial STM and LTM tasks. Children with DD performed as well as RL, but worse than CA in all STM tasks. Considering LTM, the three groups did not differ in Visual-Object and Visual-Spatial Learning tasks. In the Verbal LTM task, DD recalled significantly fewer words than CA but not RL, while CA and RL showed a similar performance. The present results suggest that when reading experience was equated, children with DD and typical readers did not differ in STM and LTM, especially in the verbal modality, weakening claims that memory has a causal effect in reading impairments.

Assessment of Psychopathological Comorbidities in Children and Adolescents With Autism Spectrum Disorder Using the Child Behavior Checklist.

Autism spectrum disorder (ASD) is characterized by psychiatric and behavioral comorbidities. The Child Behavior Checklist (CBCL) provides valid and well-established measures of emotional, behavioral, and social problems in children and adolescents. The aim of the present study was to verify whether emotional, behavioral, and social problems were modulated by ASD symptom severity, cognitive development, gender, and age by analyzing the CBCL in a large group of children and adolescents with ASD. The results show that around 30% of participants with ASD exhibited internalizing problems and only 6% externalizing problems, with males exhibiting more internalizing problems than females. No correlation was found between CBCL scores and indices of ASD severity. However, higher CBCL Total Problems scores were found in older children and in children with lower cognitive abilities. The detection of behavioral and emotional problems allows children with ASD to undergo specific and individualized treatment that takes into account their psychopathological problems.

Dissociation of spatial memory systems in Williams syndrome.

Williams syndrome (WS), a genetic deletion syndrome, is characterized by severe visuospatial deficits affecting performance on both tabletop spatial tasks and on tasks which assess orientation and navigation. Nevertheless, previous studies of WS spatial capacities have ignored the fact that two different spatial memory systems are believed to contribute parallel spatial representations supporting navigation. The place learning system depends on the hippocampal formation and creates flexible relational representations of the environment, also known as cognitive maps. The spatial response learning system depends on the striatum and creates fixed stimulus-response representations, also known as habits. Indeed, no study assessing WS spatial competence has used tasks which selectively target these two spatial memory systems. Here, we report that individuals with WS exhibit a dissociation in their spatial abilities subserved by these two memory systems. As compared to typically developing (TD) children in the same mental age range, place learning performance was impaired in individuals with WS. In contrast, their spatial response learning performance was facilitated. Our findings in individuals with WS and TD children suggest that place learning and response learning interact competitively to control the behavioral strategies normally used to support human spatial navigation. Our findings further suggest that the neural pathways supporting place learning may be affected by the genetic deletion that characterizes WS, whereas those supporting response learning may be relatively preserved. The dissociation observed between these two spatial memory systems provides a coherent theoretical framework to characterize the spatial abilities of individuals with WS, and may lead to the development of new learning strategies based on their facilitated response learning abilities.