A Meta-Analytic Review of the Efficacy of Physical Exercise Interventions on Cognition in Individuals with Autism Spectrum Disorder and ADHD

Intergenerational Metabolic Syndrome and Neuronal Network Hyperexcitability in Autism

We review evidence that suggests a role for excessive consumption of energy-dense foods, particularly fructose, and consequent obesity and insulin resistance (metabolic syndrome) in the recent increase in prevalence of autism spectrum disorders (ASD). Maternal insulin resistance, obesity, and diabetes may predispose offspring to ASD by mechanisms involving chronic activation of anabolic cellular pathways and a lack of metabolic switching to ketosis resulting in a deficit in GABAergic signaling and neuronal network hyperexcitability. Metabolic reprogramming by epigenetic DNA and chromatin modifications may contribute to alterations in gene expression that result in ASD. These mechanistic insights suggest that interventions that improve metabolic health such as intermittent fasting and exercise may ameliorate developmental neuronal network abnormalities and consequent behavioral manifestations in ASD.

Physical Activity for Autistic Adults: Recommendations for a Shift in Approach

Physical activity is beneficial for physical and mental health in the general population. Among autistic people, a range of physical and mental health conditions, particularly depression and anxiety, occur more frequently than in the general population. Physical activity interventions could help improve physical and mental health in autistic adults, but there is a lack of research in the area. The aim of this perspective article is to explore research into physical activity interventions for autistic adults, and identify gaps particularly in need of addressing. This perspective article considers six intervention studies carried out with adults, a pilot study, and seven review studies of adult and child interventions. Studies found significant increases in amount of physical activity undertaken, well-being, interaction, emotion, and regulation. There were decreases in imitative and distress behaviors. However, there were few studies, samples were small, participants all had co-occurring intellectual disability (ID), and measures were heterogeneous with lack of assessment of changes in physical fitness levels. Qualitative exploration was extremely limited. Recommendations are that there should be increased focus on research into physical activity for autistic adults, with input from autistic people to identify enjoyable, accessible activities. There should be particular consideration of longer term, sustainable activities for autistic people both with and without ID. Finally, but of major importance, there should be an increased focus on addressing mental health and anxiety through physical activity.

Exercise, spinogenesis and cognitive functions

Exercise training improves mental and cognitive functions by enhancing neurogenesis and neuroprotection. Recent studies suggest the facilitation of spinogenesis across different brain regions including hippocampus and cerebral cortex by physical activity. In this article we will summarize major findings for exercise effects on synaptogenesis and spinogenesis, in order to provide mechanisms for exercise intervention of both psychiatric diseases and neurodegenerative disorders. We will also revisit major findings for molecular mechanism governing exercise-related spinogenesis, and will discuss the screening for novel factors, or exerkines, whose levels are correlated with endurance training and affect neural plasticity. We believe that further studies focusing on the molecular mechanism of exercise-mediate spinogenesis should benefit the optimization of exercise therapy in clinics and the evaluation of treatment efficiency using specific biomarkers.

Effects of Exercise on Cognitive Performance in Children and Adolescents with ADHD: Potential Mechanisms and Evidence-based Recommendations

Attention Deficit Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder with a complex symptomatology, and core symptoms as well as functional impairment often persist into adulthood. Recent investigations estimate the worldwide prevalence of ADHD in children and adolescents to be ~7%, which is a substantial increase compared to a decade ago. Conventional treatment most often includes pharmacotherapy with central nervous stimulants, but the number of non-responders and adverse effects call for treatment alternatives. Exercise has been suggested as a safe and low-cost adjunctive therapy for ADHD and is reported to be accompanied by positive effects on several aspects of cognitive functions in the general child population. Here we review existing evidence that exercise affects cognitive functions in children with and without ADHD and present likely neurophysiological mechanisms of action. We find well-described associations between physical activity and ADHD, as well as causal evidence in the form of small to moderate beneficial effects following acute aerobic exercise on executive functions in children with ADHD. Despite large heterogeneity, meta-analyses find small positive effects of exercise in population-based control (PBC) children, and our extracted effect sizes from long-term interventions suggest consistent positive effects in children and adolescents with ADHD. Paucity of studies probing the effect of different exercise parameters impedes finite conclusions in this regard. Large-scale clinical trials with appropriately timed exercise are needed. In summary, the existing preliminary evidence suggests that exercise can improve cognitive performance intimately linked to ADHD presentations in children with and without an ADHD diagnosis. Based on the findings from both PBC and ADHD children, we cautiously provide recommendations for parameters of exercise.

Physical Activity, Screen Time, and Sleep in Children With ADHD

Background: Children with attention deficit hyperactivity disorder (ADHD) are at increased risk for poor health and obesity. The authors describe obesity-related movement behaviors in children with ADHD, determine higher risk groups, and compare with children with other disorders. Methods: Physical activity (PA), sleep, and screen time of children with ADHD (aged 6-18 y) were compared with recommendations and with behaviors of children with autism, asthma, and a normative group using 2011 National Survey of Child Health data. Results: Approximately one-third of children with ADHD participated in daily PA and half in sports in the past year. Older children with ADHD were less likely to get daily PA, get enough sleep, and limit screen time to <2 hours per day. Obese children had lower odds of daily PA. Children who had lower socioeconomic status, or severe ADHD, had lower odds of sports participation. Children with ADHD had 50% lower odds of sports participation than children with asthma. Conclusions: Children with ADHD did not engage in recommended amounts of PA, sleep, and screen time. Children with ADHD who are older, poor, obese, and/or with more severe symptoms are at higher risk for suboptimal movement behaviors. These domains represent novel treatment targets in ADHD youth.

Autism Spectrum Disorders and ADHD: Overlapping Phenomenology, Diagnostic Issues, and Treatment Considerations

PURPOSE OF REVIEW

Autism spectrum disorder (ASD) and attention deficit/hyperactivity disorder (ADHD) are both increasing in prevalence and commonly co-occur with each other. The goal of this review is to outline what has been published recently on the topics of ASD, ADHD, and the comorbid state (ASD+ADHD) with a particular focus on shared phenomenology, differential diagnosis, and treatment considerations.

RECENT FINDINGS

ASD and ADHD have shared genetic heritability and are both associated with shared impairments in social functioning and executive functioning. Quantitative and qualitative differences exist, however, in the phenotypic presentations of the impairments which characterize ASD and ADHD. For ASD interventions to be maximally efficacious, comorbid ADHD needs to be considered (and vice versa). The research on ASD and ADHD suggests some overlap between the two disorders yet enough differences to indicate that these conditions are sufficiently distinct to warrant separate diagnostic categories.

Effects of a Physical Exercise Program (PEP-Aut) on Autistic Children's Stereotyped Behavior, Metabolic and Physical Activity Profiles, Physical Fitness, and Health-Related Quality of Life: A Study Protocol

Physical exercise has shown positive effects on symptomatology and on the reduction of comorbidities in population with autism spectrum disorder (ASD). However, there is still no consensus about the most appropriate exercise intervention model for children with ASD. The physical exercise program for children with autism (PEP-Aut) protocol designed allow us to (i) examine the multivariate associations between ASD symptoms, metabolic profile, physical activity level, physical fitness, and health-related quality of life of children with ASD; (ii) assess the effects of a 40-week exercise program on all these aspects of children with ASD. The impact of the exercise program will be assessed based on the sequence of the two phases. Phase 1 is a 12-week cross-sectional study assessing the symptomatology, metabolic profile, physical fitness and physical activity levels, socioeconomic status profile, and health-related quality of life of participants. This phase is the baseline of the following phase. Phase 2 is a 48-week intervention study with a 40-week intervention with exercise that will take place in a specialized center for children with ASD in the city of Maceió-Alagoas, Brazil. The primary outcomes will be change in the symptomatic profile and the level of physical activity of children. Secondary outcomes will be anthropometric and metabolic profiles, aerobic function, grip strength, socioeconomic status, and health-related quality of life. The study will provide critical information on the efficacy of exercise for children with ASD and help guide design and delivery of future programs.

Factors affecting dance exercise performance in students at a special needs school

BACKGROUND

In Japan, dance exercise has been introduced as a compulsory element of health and physical education, but there is a considerable discrepancy in the levels of performance among students with intellectual disability (ID) at special needs schools. The aim of this study was therefore to identify the factors affecting the performance of dance exercise in students with ID.

METHODS

A 4 month dance exercise program was implemented for junior high school students at a special needs school, and the performance of 32 students at 22 sessions was assessed quantitatively according to calorie use during exercise and performance proficiency score. The measures were compared according to gender, age, body mass index, diagnosis, and development quotient (DQ) score.

RESULTS

Performance in many students improved with repetition and reached the highest attainment level at around the third month. Male gender and older age had a significant positive impact on calorie use, whereas diagnosis of Down syndrome and higher DQ score had a significant positive impact on proficiency score. Four students with poor performance were all female students with autism.

CONCLUSION

This study provides some possible explanations for differences in the levels of dance performance among students with ID.

Assessing Parent Perceptions of Physical Activity in Families of Toddlers With Neurodevelopmental Disorders: The Parent Perceptions of Physical Activity Scale (PPPAS)

PURPOSE

The purpose of this study was to examine a new tool (PPPAS = Parent Perceptions of Physical Activity Scale-Preschool) developed to study parental perceptions of physical activity (PA) among parents of toddler and preschool age children.

METHOD

143 children (mean age 31.65 months; 75% male) and their parents were recruited from a neurodevelopmental clinic. Parents completed questionnaires, and both a psychologist and a physician evaluated the children. Eighty-three percent of the children received a diagnosis of Autism Spectrum Disorder; 20% of the children had a BMI > 85th percentile. Analyses were conducted to evaluate the reliability, concurrent validity, discriminant validity, and predictive validity of PPPAS scores.

RESULTS

Results supported a two-factor structure: Perceptions of the Benefits of PA and the Barriers to PA. The internal consistency of scores was good for both PPPAS subscales, derived from the two factors. Parent perceptions of barriers to PA were significantly correlated with delays in overall adaptive functioning, daily living skills, socialization, and motor skills. When a child's motor skills were delayed, parents were less likely to believe PA was beneficial and perceived more barriers to PA. Parent perceptions of barriers to PA predicted parent-reported weekly unstructured PA and ratings of how physically active their child was compared with other children.

CONCLUSION

We present the PPPAS-Preschool for use in pediatric exercise research and discuss potential applications for the study of parent perceptions of PA in young children.

Structural brain imaging correlates of ASD and ADHD across the lifespan: a hypothesis-generating review on developmental ASD-ADHD subtypes

We hypothesize that it is plausible that biologically distinct developmental ASD-ADHD subtypes are present, each characterized by a distinct time of onset of symptoms, progression and combination of symptoms. The aim of the present narrative review was to explore if structural brain imaging studies may shed light on key brain areas that are linked to both ASD and ADHD symptoms and undergo significant changes during development. These findings may possibly pinpoint to brain mechanisms underlying differential developmental ASD-ADHD subtypes. To this end we brought together the literature on ASD and ADHD structural brain imaging symptoms and particularly highlight the adolescent years and beyond. Findings indicate that the vast majority of existing MRI studies has been cross-sectional and conducted in children, and sometimes did include adolescents as well, but without explicitly documenting on this age group. MRI studies documenting on age effects in adults with ASD and/or ADHD are rare, and if age is taken into account, only linear effects are examined. Data from various studies suggest that a crucial distinctive feature underlying different developmental ASD-ADHD subtypes may be the differential developmental thinning patterns of the anterior cingulate cortex and related connections towards other prefrontal regions. These regions are crucial for the development of cognitive/effortful control and socio-emotional functioning, with impairments in these features as key to both ASD and ADHD.