April 18, 2024
ADHD is associated with impaired executive functions. These functions, associated with the prefrontal cortex, control thoughts and goal-oriented behaviors, including inhibition, cognitive flexibility, and working memory.
To what extent can meditation-based mind-body interventions (MBIs) such as yoga, Tai Chi, Qigong, and Mindfulness improve symptoms and executive functioning in persons with ADHD?
To explore this question a Chinese study team performed a systematic search of the peer-reviewed medical literature for randomized controlled trials (RCTs) in either Chinese or English that could be subjected to meta-analysis.
Nineteen RCTS, all but one in English, met criteria for inclusion. Nine involved children and adolescents, and ten involved adults. Fifteen of the studies looked at mindfulness, two at yoga, and two at Tai Chi.
Eight studies were rated as high quality, and the other eleven moderate quality. However, “none of the studies succeeded in blinding participants and therapists due to the challenges of performing double-blind procedures in non-pharmacological studies.”
A meta-analysis of fourteen RCTs totaling 832 participants found small but significant improvements for inattention symptoms. Longer trainings (over 16 hours total) increased the effect size to small-to-medium. Trainings were more successful with adults (small-to-medium effect size) than with children and adolescents (improvements not significant).
Another meta-analysis, of fifteen RCTs combining 868 participants, likewise reported small but significant improvements for hyperactivity/impulsivity symptoms. In this case the trainings were more successful with children and adolescents than with adults, where outcomes lost significance. Longer trainings (over 16 hours total) did not improve outcomes, and in fact made gains insignificant.
A third meta-analysis, of ten RCTs with a combined 558 participants, found small-to-medium effect size improvements in executive functioning. Trainings were effective for all ages. Longer trainings (over 16 hours total) increased the effect size to medium. Direct measurement of behavioral tasks, as opposed to relying on questionnaires, likewise increased the effect size to medium.
For all three meta-analyses, there was virtually no between-study variation (heterogeneity), meaning these outcomes were consistent across studies. There were also no signs of publication bias.
Overall, MBIs improved ADHD symptoms with small effect size, but executive functioning – arguably the more important of the two criteria for ultimate well-being – with medium effect size when measured directly after over 16 hours of training.
The authors concluded, “This meta-analysis confirmed that MBIs, such as mindfulness, Tai Chi, and yoga, had small to medium intervention effects on ADHD symptoms and EF [executive function] compared with the control condition. Although the results of the subgroup analysis suggest that age, interventions, and total time may be important moderators affecting MBIs intervention on the symptoms (inattention, hyperactivity/ impulsivity) of ADHD, while interventions and total time may be moderators affecting EF, more research needs to be conducted to support these findings.”
REFERENCES
Zeping Zhang, Xiaolong Chang, Weijing Zhang, Suyong Yang, and Guangsheng Zhao, “The Effect of Meditation-Based Mind-Body Interventions on Symptoms and Executive Function in People With ADHD: A Meta-Analysis of Randomized Controlled Trials,” Journal of Attention Disorders (2023), 1-15, https://doi.org/10.1177/10870547231154897.
This study investigates how certain genetic disorders, called RASopathies, affect the structure of the brain in children. RASopathies are conditions caused by mutations in a specific signaling pathway in the body. Two common RASopathies are Noonan syndrome (NS) and neurofibromatosis type 1 (NF1), both of which are linked to a higher risk of autism spectrum disorder (ASD) and attention deficit and hyperactivity disorder (ADHD).
The researchers analyzed brain scans of children with RASopathies (91 participants) and compared them to typically developing children (74 participants). They focused on three aspects of brain structure: surface area (SA), cortical thickness (CT), and subcortical volumes.
The results showed that children with RASopathies had both similarities and differences in their brain structure compared to typically developing children. They had increased SA in certain areas of the brain, like the precentral gyrus, but decreased SA in other regions, such as the occipital regions. Additionally, they had thinner CT in the precentral gyrus. However, the effects on subcortical volumes varied between the two RASopathies: children with NS had decreased volumes in certain structures like the striatum and thalamus, while children with NF1 had increased volumes in areas like the hippocampus, amygdala, and thalamus.
Overall, this study highlights how RASopathies can impact the development of the brain in children. The shared effects on SA and CT suggest a common influence of RASopathies on brain development, which could be important for developing targeted treatments in the future.
In summary, understanding how these genetic disorders affect the brain's structure can help researchers and healthcare professionals develop better treatments for affected children.
In a recent study, researchers delved into the complex interplay of cognitive processes and eye movements in children with dyslexia and Attention-Deficit/Hyperactivity Disorder. Their findings shed light on predictive models for reading outcomes in these children compared to typical readers.
The study involved 59 children: 19 typical readers, 21 with ADHD, and 19 with developmental dyslexia (DD), all in the 4th grade and around 9 years old on average. Each group underwent thorough neuropsychological and linguistic assessments to understand their psycholinguistic profiles.
During the study, participants engaged in a silent reading task where the text underwent lexical manipulation. Researchers then analyzed eye movement data alongside cognitive factors like memory, attention, and visual processes.
Using multinomial logistic regression, the researchers evaluated predictive models based on three key measures: a linguistic model focusing on phonological awareness, rapid naming, and reading fluency; a cognitive neuropsychological model incorporating memory, attention, and visual processes; and an additive model combining lexical word properties with eye-tracking data, specifically examining word frequency and length effects.
By integrating eye movement data with cognitive factors, the researchers enhanced their ability to predict the development of dyslexia or ADHD, in comparison to typically developing readers. This approach significantly improved the accuracy of predicting reading outcomes in children with learning disabilities.
These findings have profound implications for understanding and addressing reading challenges in children. By considering both cognitive processes and eye movement patterns, educators and clinicians can develop more effective interventions tailored to the specific needs of children with dyslexia and ADHD.
The Study Setup
The researchers recruited children aged 6-12 years diagnosed with ASD and/or ADHD, along with their non-ASD/ADHD siblings and the unrelated non-ASD/ADHD volunteers. The diagnoses were confirmed using standardized assessments like the Autism Diagnostic Observation Schedule-2 (ADOS-2). The study looked at gut microbial diversity using advanced DNA extraction and sequencing techniques, comparing alpha-diversity indices (which reflect the variety and evenness of microbial species within each gut sample) across different groups. They also assessed dietary diversity through standardized questionnaires.
Key Findings
The study included 98 subjects, comprising children with ASD, ADHD, both ASD and ADHD, their non-ASD/ADHD siblings, and the unrelated controls. Here's what they discovered:
What Does This Mean?
The study highlights intriguing connections between gut microbiota and neurodevelopmental disorders like ASD and ADHD. The lower gut microbial diversity observed in children with ASD points towards potential links between gut health and the pathophysiology of ASD. Understanding these connections is crucial for developing targeted therapeutic interventions.
Implications and Future Directions
This research underscores the importance of considering gut microbiota in the context of neurodevelopmental disorders. Moving forward, future studies should account for factors like co-occurrence of ASD and ADHD, as well as carefully control for dietary influences. This will help unravel the complex interplay between gut microbiota, diet, and neurodevelopmental disorders, paving the way for innovative treatments and interventions.
In summary, studies like this shed light on the intricate relationship between our gut health, diet, and brain function. By unraveling these connections, researchers are opening new avenues for understanding and potentially treating conditions like ASD and ADHD.
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