Deviations from a typical development of the cerebellum in youth are associated with psychopathology, executive functions and educational outcomes

BACKGROUND

Understanding deviations from typical brain development is a promising approach to comprehend pathophysiology in childhood and adolescence. We investigated if cerebellar volumes different than expected for age and sex could predict psychopathology, executive functions and academic achievement.

METHODS

Children and adolescents aged 6-17 years from the Brazilian High-Risk Cohort Study for Mental Conditions had their cerebellar volume estimated using Multiple Automatically Generated Templates from T1-weighted images at baseline (n = 677) and at 3-year follow-up (n = 447). Outcomes were assessed using the Child Behavior Checklist and standardized measures of executive functions and school achievement. Models of typically developing cerebellum were based on a subsample not exposed to risk factors and without mental-health conditions (n = 216). Deviations from this model were constructed for the remaining individuals (n = 461) and standardized variation from age and sex trajectory model was used to predict outcomes in cross-sectional, longitudinal and mediation analyses.

RESULTS

Cerebellar volumes higher than expected for age and sex were associated with lower externalizing specific factor and higher executive functions. In a longitudinal analysis, deviations from typical development at baseline predicted inhibitory control at follow-up, and cerebellar deviation changes from baseline to follow-up predicted changes in reading and writing abilities. The association between deviations in cerebellar volume and academic achievement was mediated by inhibitory control.

CONCLUSIONS

Deviations in the cerebellar typical development are associated with outcomes in youth that have long-lasting consequences. This study highlights both the potential of typical developing models and the important role of the cerebellum in mental health, cognition and education.

Association between preterm infant size at 1 year and ADHD later in life: data from 1993 and 2004 Pelotas Birth Cohorts

The objective of this study is to examine the association between preterm infants' size at 1 year and attention-deficit/hyperactivity disorder (ADHD) assessed categorically and dimensionally in childhood and adolescence. We studied infants born < 37 weeks' gestation from two Brazilian birth cohorts (n = 653). ADHD was evaluated using the Development and Well-Being Assessment (DAWBA) interview at the age of 6 years in one cohort and by a structured interview according to DSM-5 criteria at 18 years in the other one. The presence of child attention difficulties was measured by the Strengths and Difficulties Questionnaire (SDQ) at 6 and 11 years in the 2004 and 1993 cohorts, respectively. We estimated associations of weight, length, head circumference, and BMI z-scores at 1-year chronological age with ADHD using Poisson Regression Model; and with attention difficulties using Linear Regression, adjusting for covariates. Mean birth weight was 2500 g and gestational age was 34.5 weeks. The aggregated ADHD prevalence in the two cohorts was 2.7%, and the median score for attention difficulties was 3.0. We found that increased head circumference at 1 year was associated with a lower risk of ADHD diagnosis (RR = 0.7, 95% CI 0.4, 0.9; p = 0.04 per standard deviation difference) and with fewer dimensional attention symptoms. In sensitivity analysis with other mental disorders, head circumference was associated with depression, but not with anxiety. Our findings emphasize poor head growth in the first year of life as a potential determinant of attentional difficulties in the preterm infant population.

Longitudinal associations between positive attributes and psychopathology and their interactive effects on educational outcomes

Psychopathology is associated with impaired learning and early termination of schooling, whereas positive attributes are associated with better educational outcomes. However, it is important to understand if and how psychopathology and positive attributes longitudinally impact each other so we could shed light on where to intervene to promote educational outcomes through these constructs. A large prospective school-based community cohort of youths (5-15 years of age, 45% female) were assessed and followed up for 3 years (n = 2010; 80% retention). We assessed the longitudinal impact of positive attributes (Youth Strength Inventory) and psychopathology (bifactor model of Strengths and Difficulties Questionnaire) using a cross-lagged panel model. We also used generalized mixed effects models to investigate how these both constructs predict school dropout and literacy, adjusting for confounders and testing their interaction. Positive attributes negatively predicted, and were negatively predicted by, the general factor of psychopathology and conduct problems in the cross-lagged panel model. Positive attributes (OR = 0.57, 95% CI [0.44, 0.73], p < 0.001) and specific conduct symptoms (OR = 2.33, 95% CI [1.64, 3.33], p < 0.001) predicted school dropout, whereas the general factor of psychopathology predicted lower literacy ability (β =  - 0.08, 95% CI [- 0.11, - 0.05], p < 0.001). However, the protective association of positive attributes on school dropout decreases as the general factor of psychopathology increases. These findings provide new evidence that positive attributes and psychopathology mutually influence each other over development and have interactive effects on educational outcomes.

Desempenho em Aritmética de Estudantes com e sem Sintomas de TDAH

Resumo O Transtorno de Déficit de Atenção/Hiperatividade (TDAH) é um transtorno que frequentemente acarreta prejuízos ao desempenho acadêmico. O presente estudo teve como objetivo verificar a extensão desses prejuízos no desempenho aritmético, comparando estudantes com sintomas de TDAH com o de seus pares sem TDAH. O desempenho aritmético de 93 estudantes com sintomas de TDAH e 447 estudantes sem TDAH, entre 7 e 16 anos, de escolas públicas de Porto Alegre (3º a 9º ano), foi avaliado pelo Subteste de Aritmética do TDE. Estudantes com sintomas de TDAH apresentaram escores mais baixos e uma quantidade maior de erros de procedimento do que os estudantes sem o transtorno. Os resultados sugerem que sintomas frequentes de TDAH têm relação com maior ocorrência de erros no desempenho em aritmética dos estudantes avaliados neste estudo.

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.

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.

Methylphenidate Alters Functional Connectivity of Default Mode Network in Drug-Naive Male Adults With ADHD

Objective: This study evaluated the hypothesis that methylphenidate immediate release (MPH-IR) treatment would improve Default Mode Network (DMN) within-connectivity. Method: Resting-state functional connectivity of the main nodes of DMN was evaluated in a highly homogeneous sample of 18 drug-naive male adult participants with ADHD. Results: Comparing resting-state functional connectivity functional magnetic resonance imaging (R-fMRI) scans before and after MPH treatment focusing exclusively on within-DMN connectivity, we evidenced the strengthening of functional connectivity between two nodes of the DMN: posterior cingulate cortex (PCC) and left lateral parietal cortex (LLP). Conclusion: Our results contribute to the further understanding on how MPH affects functional connectivity within DMN of male adults with ADHD and corroborate the hypothesis of ADHD being a delayed neurodevelopmental disorder.

Computerized cognitive training in children and adolescents with attention deficit/hyperactivity disorder as add-on treatment to stimulants: feasibility study and protocol description

Abstract Background Cognitive training has received increasing attention as a non-pharmacological approach for the treatment of attention deficit/hyperactivity disorder (ADHD) in children and adolescents. Few studies have assessed cognitive training as add-on treatment to medication in randomized placebo controlled trials. The purpose of this preliminary study was to explore the feasibility of implementing a computerized cognitive training program for ADHD in our environment, describe its main characteristics and potential efficacy in a small pilot study. Methods Six ADHD patients aged 10-12-years old receiving stimulants and presenting residual symptoms were enrolled in a randomized clinical trial to either a standard cognitive training program or a controlled placebo condition for 12 weeks. The primary outcome was core ADHD symptoms measured using the Swanson, Nolan and Pelham Questionnaire (SNAP-IV scale). Results We faced higher resistance than expected to patient enrollment due to logistic issues to attend face-to-face sessions in the hospital and to fill the requirement of medication status and absence of some comorbidities. Both groups showed decrease in parent reported ADHD symptoms without statistical difference between them. In addition, improvements on neuropsychological tests were observed in both groups – mainly on trained tasks. Conclusions This protocol revealed the need for new strategies to better assess the effectiveness of cognitive training such as the need to implement the intervention in a school environment to have an assessment with more external validity. Given the small sample size of this pilot study, definitive conclusions on the effects of cognitive training as add-on treatment to stimulants would be premature.

Long-Term Efficacy of Methylphenidate Immediate-Release for the Treatment of Childhood ADHD

OBJECTIVE

To evaluate the long-term effects of methylphenidate imediate-release (MPH-IR), and to confirm the efficacy established in previous meta-analyses of short-term studies.

METHOD

Published and unpublished studies in which participants were treated with MPH-IR for 12 weeks or more were searched. Pooled effect sizes from these studies were computed with the DerSimonian and Laird random-effect model. Meta-regression analysis was conducted to estimate covariates associated with treatment effects.

RESULTS

Seven studies were included. Pooled parents ratings for inattention and hyperactivity/impulsivity resulted in standardized mean difference (SMD) = 0.96 (95% confidence interval [CI] = [0.60, 1.32]) and SMD = 1.12 (95% CI = [0.85, 1.39]), respectively; pooled teachers ratings showed SMD = 0.98 (95% CI = [0.09, 1.86]) for inattention and SMD = 1.25 (95% CI = [0.7, 1.81]) for hyperactivity/impulsivity. No evidence of association of any covariates with treatment effect was detected in the meta-regression.

CONCLUSION

MPH-IR is efficacious for childhood ADHD for periods longer than 12 weeks.

Transcranial direct current stimulation improves short-term memory in an animal model of attention-deficit/hyperactivity disorder

Attention deficit hyperactivity disorder (ADHD) is characterized by impairing levels of hyperactivity, impulsivity and inattention. However, different meta-analyses have reported disruptions in short and long-term memory in ADHD patients. Previous studies indicate that mnemonic dysfunctions might be the result of deficits in attentional circuits, probably due to ineffective dopaminergic modulation of hippocampal synaptic plasticity. In this study we aimed to evaluate the potential therapeutic effects of a neuromodulatory technique, transcranial direct current stimulation (tDCS), in short-term memory (STM) deficits presented by the spontaneous hypertensive rats (SHR), the most widely used animal model of ADHD. Adult male SHR and Wistar Kyoto rats (WKY) were subjected to a constant electrical current of 0.5 mA intensity applied on the frontal cortex for 20 min/day during 8 days. STM was evaluated with an object recognition test conducted in an open field. Exploration time and locomotion were recorded, and brain regions were dissected to determine dopamine and BDNF levels. SHR spent less time exploring the new object when compared to WKY, and tDCS improved object recognition deficits in SHR without affecting WKY performance. Locomotor activity was higher in SHR and it was not affected by tDCS. After stimulation, dopamine levels were increased in the hippocampus and striatum of both strains, while BDNF levels were increased only in the striatum of WKY. These findings suggest that tDCS on the frontal cortex might be able to improve STM deficits present in SHR, which is potentially related to dopaminergic neurotransmission in the hippocampus and striatum of those animals.

Attention-based classification pattern, a research domain criteria framework, in youths with bipolar disorder and attention-deficit/hyperactivity disorder

OBJECTIVE

The National Institute of Mental Health has initiated the Research Domain Criteria (RDoC) project. Instead of using disorder categories as the basis for grouping individuals, the RDoC suggests finding relevant dimensions that can cut across traditional disorders. Our aim was to use the RDoC's framework to study patterns of attention deficit based on results of Conners' Continuous Performance Test (CPT II) in youths diagnosed with bipolar disorder (BD), attention-deficit/hyperactivity disorder (ADHD), BD+ADHD and controls.

METHOD

Eighteen healthy controls, 23 patients with ADHD, 10 with BD and 33 BD+ADHD aged 12-17 years old were assessed. Pattern recognition was used to partition subjects into clusters based simultaneously on their performance in all CPT II variables. A Fisher's linear discriminant analysis was used to build a classifier.

RESULTS

Using cluster analysis, the entire sample set was best clustered into two new groups, A and B, independently of the original diagnoses. ADHD and BD+ADHD were divided almost 50% in each subgroup, and there was an agglomeration of controls and BD in group B. Group A presented a greater impairment with higher means in all CPT II variables and lower Children's Global Assessment Scale. We found a high cross-validated classification accuracy for groups A and B: 95.2%. Variability of response time was the strongest CPT II measure in the discriminative pattern between groups A and B.

CONCLUSION

Our classificatory exercise supports the concept behind new approaches, such as the RDoC framework, for child and adolescent psychiatry. Our approach was able to define clinical subgroups that could be used in future pathophysiological and treatment studies.

Mechanisms underpinning inattention and hyperactivity: neurocognitive support for ADHD dimensionality

BACKGROUND

Taxometric and behavioral genetic studies suggest that attention deficit hyperactivity disorder (ADHD) is best modeled as a dimension rather than a category. We extended these analyses by testing for the existence of putative ADHD-related deficits in basic information processing (BIP) and inhibitory-based executive function (IB-EF) in individuals in the subclinical and full clinical ranges. Consistent with the dimensional model, we predicted that ADHD-related deficits would be expressed across the full spectrum, with the degree of deficit linearly related to the severity of the clinical presentation.

METHOD

A total of 1547 children (aged 6-12 years) participated in the study. The Development and Well-Being Assessment (DAWBA) was used to classify children into groups according to levels of inattention and hyperactivity independently: (1) asymptomatic, (2) subthreshold minimal, (3) subthreshold moderate and (4) clinical ADHD. Neurocognitive performance was evaluated using a two-choice reaction time task (2C-RT) and a conflict control task (CCT). BIP and IB-EF measures were derived using a diffusion model (DM) for decomposition of reaction time (RT) and error data.

RESULTS

Deficient BIP was found in subjects with minimal, moderate and full ADHD defined in terms of inattention (in both tasks) and hyperactivity/impulsivity dimensions (in the 2C-RT). The size of the deficit increased in a linear manner across increasingly severe presentations of ADHD. IB-EF was unrelated to ADHD.

CONCLUSIONS

Deficits in BIP operate at subclinical and clinical levels of ADHD. The linear nature of this relationship provides support for a dimensional model of ADHD in which diagnostic thresholds are defined in terms of clinical and societal burden rather than representing discrete pathophysiological states.

Specificity of basic information processing and inhibitory control in attention deficit hyperactivity disorder

BACKGROUND

Both inhibitory-based executive functioning (IB-EF) and basic information processing (BIP) deficits are found in clinic-referred attention deficit hyperactivity disorder (ADHD) samples. However, it remains to be determined whether: (1) such deficits occur in non-referred samples of ADHD; (2) they are specific to ADHD; (3) the co-morbidity between ADHD and oppositional defiant disorder/conduct disorder (ODD/CD) has additive or interactive effects; and (4) IB-EF deficits are primary in ADHD or are due to BIP deficits.

METHOD

We assessed 704 subjects (age 6-12 years) from a non-referred sample using the Development and Well-Being Assessment (DAWBA) and classified them into five groups: typical developing controls (TDC; n = 378), Fear disorders (n = 90), Distress disorders (n = 57), ADHD (n = 100), ODD/CD (n = 40) and ADHD+ODD/CD (n = 39). We evaluated neurocognitive performance with a Two-Choice Reaction Time Task (2C-RT), a Conflict Control Task (CCT) and a Go/No-Go (GNG) task. We used a diffusion model (DM) to decompose BIP into processing efficiency, speed-accuracy trade-off and encoding/motor function along with variability parameters.

RESULTS

Poorer processing efficiency was found to be specific to ADHD. Faster encoding/motor function differentiated ADHD from TDC and from fear/distress whereas a more cautious (not impulsive) response style differentiated ADHD from both TDC and ODD/CD. The co-morbidity between ADHD and ODD/CD reflected only additive effects. All ADHD-related IB-EF classical effects were fully moderated by deficits in BIP.

CONCLUSIONS

Our findings challenge the IB-EF hypothesis for ADHD and underscore the importance of processing efficiency as the key specific mechanism for ADHD pathophysiology.

[Translation and adaptation of the Motorcycle Rider Behavior Questionnaire: a Brazilian version]

Traffic accidents are a leading cause of death in young adults. In Brazil, traffic accidents are proportionally more prevalent among motorcyclists as compared to automobile drivers. Although numerous data indicate that individual characteristics are involved in traffic accident risk, there is no instrument in Brazil to assess motorcyclists' traffic behavior. The authors thus proposed to perform translation and cultural adaptation of the Motorcycle Rider Behavior Questionnaire (MRBQ) into Brazilian Portuguese. The translation process consisted of: two independent translations into Brazilian Portuguese; unification of the translations; back-translation into English; formal assessment of semantic equivalence; application of a summary version in a convenience sample of motorcyclists; generation of a final version; and back-translation and submission to the original author, who approved this version. The Brazilian version maintained its semantic equivalence and was accepted by the convenience sample, an important characteristic for a self-completed instrument. Further studies are necessary to evaluate the questionnaire's psychometric properties in the Brazilian cultural context.

The prevalence of psychopathology in offspring of bipolar women from a Brazilian tertiary center

OBJECTIVE: No previous study has assessed the occurrence of psychopathology in offspring of bipolar women from South America. The objective of this study was to assess the prevalence of psychopathology in offspring of bipolar mothers from Brazil compared with two control groups. METHOD: Children and adolescents aged 6 to 18 years of bipolar disorders mothers (n = 43), mothers with other mild to moderate mental disorders (n = 53) and mothers without any psychiatric disorder (n = 53) were evaluated using the Kiddie Schedule for Affective Disorders and Schizophrenia present and lifetime version, the Child Behavior Checklist and the Youth Self-Report. Raters were blind to the mothers' diagnoses, who were interviewed by means of the Structured Clinical Interview. RESULTS: Bipolar offspring had twice the chance of having one or more lifetime Axis I diagnoses [prevalence ratio = 2.11 (95% CI: 1.30-3.42) and p = 0.003] and 2.8 higher risk of having a lifetime anxiety disorder [prevalence ratio = 2.83 (95% CI: 1.39-5.78) e p = 0.004] than the offspring of mothers with no mental disorder. In addition, significantly higher scores on Child Behavior Checklist thought problems and Youth Self-Report social problems, as well as anxiety/depression and internalizing problems were observed. CONCLUSION: Our results confirm previous findings suggesting higher psychiatric problems in offspring of bipolar mothers and extend them to the Brazilian society

TDAH: remissão na adolescência e preditores de persistência em adultos

Embora no passado se acreditasse que o TDAH persistia somente até a adolescência, atualmente já há um corpo sólido de conhecimento científico evidenciando que o TDAH freqüentemente persiste em adultos que foram diagnosticados como tendo TDAH na infância. São poucos os relatos na literatura sobre o padrão dessa evolução dos sintomas e, principalmente, sobre os fatores que predizem esse desfecho. O objetivo deste artigo é revisar a literatura científica sobre o TDAH, com foco específico em dados sobre remissão dos sintomas na adolescência e preditores de persistência do transtorno até a vida adulta. São apresentados dados de prevalência na adolescência e idade adulta, fatores relacionados à variabilidade de resultados entre os estudos, potenciais fatores de risco de persistência e o único estudo delineado especificamente com o objetivo de avaliar um conjunto abrangente de preditores do transtorno da infância à idade adulta.