Osmotic Release Oral System-Methylphenidate Hydrochloride (OROS-MPH) versus atomoxetine on executive function improvement and clinical effectiveness in ADHD: A randomized controlled trial

Systematic Review of Executive Function Stimulation Methods in the ADHD Population

Background/Objectives: Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterized by elevated motor activity, impulsivity, and attention deficit. Approximately 5% of the population suffers from this disorder. Among the key explanations of ADHD, executive functions play an important role in understanding the symptomatology present in this disorder and in determining the main treatment strategies for affected patients. We present a systematic review that seeks to identify the treatment methods developed to support executive functions in individuals with ADHD. Methods: Articles were analyzed in the SCOPUS, PUBMED, and Science Direct databases. Initially, 739 articles were found. After applying inclusion and exclusion criteria, 30 articles remained and were included in the data extraction process. Results: Among the primary treatments identified, 14 studies propose psychological training for executive functions, 9 studies recommend medication, 5 studies suggest digital interventions, and 1 study advocates for sports as beneficial for executive functions. Conclusions: The data are discussed around the need to develop new proposals to enhance the executive functions of individuals with ADHD, thereby improving their performance in educational, personal, social, and family activities impacted by this disorder.

Is Processing Speed (Gs) related to Hyperactivity (As a Narrow Cognitive Area of Gps): A Dimensional Approach to Heterogeneity of Clinical and WISC-IV Cognitive Profiles in ADHD From RDoC/HiTOP Perspective

OBJECTIVE

The aim of this study was to investigate the relationship between symptomatology and the Wechsler Intelligence Scale for Children, Fourth Edition (WISC-IV) cognitive profiles in Attention Deficit and Hyperactivity Disorder (ADHD), taking into account clinical heterogeneity.

METHOD

The WISC-IV was administered to 60 children aged 6 to 13 years with ADHD who had not previously taken psychotropic medication. Conners Teacher-Rating Scale (CTRS-R/L) and Conners Parent-Rating Scale (CPRS-R/L) were completed by parents and teachers.

RESULTS

We found a statistically significant positive correlation between the symptoms of hyperactivity/impulsivity and PSI (Processing Speed Index). A statistically significant negative correlation was found between the CTRS-R/L's DSM-IV Inattentive subscale and PRI (Perceptual Reasoning Index). No relationship was found between the inattention or hyperactivity/impulsivity symptomatology with Working Memory Index (WMI). WMI stood out as the most frequently reported weakness among the four index scores.

CONCLUSION

Considering the relationship between the cognitive domains of RDoC (Research Domain Criteria) and dimensions of HiTOP with the ADHD symptom clusters, the assessment of cognitive and behavioral symptoms may be useful for phenotyping ADHD. According to the CHC (Cattell-Horn-Carroll) theory; the positive correlation level between PSI, which is accepted as Gs, and hyperactivity/impulsivity symptoms in people with ADHD may be due to the fact that hyperactivity is one of the narrow cognitive domains of Gps.

Selective Effects of Methylphenidate on Attention and Inhibition in 22q11.2 Deletion Syndrome: Results From a Clinical Trial

BACKGROUND

Attention deficit and/or hyperactivity disorder (ADHD) is the most prevalent psychiatric disorder in children with 22q11.2 deletion syndrome (22q11DS) and frequently persists into adulthood. Although medication with stimulant has been demonstrated to be highly effective in idiopathic ADHD, evidence in 22q11DS is still scarce. Previous studies have shown safety and effectiveness of methylphenidate (MPH) on core symptoms of ADHD as well as improvement of associated cognitive deficits. However, only a limited number of cognitive domains have been explored.

METHODS

Twenty-three participants with 22q11DS and attention difficulties, aged 8-24 years, entered a clinical trial aiming to specify the effects of MPH on clinical symptoms, cognition, and daily-life behavior. The effects of treatment were compared with/without medication in a within-subject design. The trial included both participants naïve to the molecule and chronic users.

RESULTS

Benefit from the treatment was demonstrated through a decrease in core ADHD symptoms, specifically inattention symptoms, and improvement of cognitive measures of attention and inhibition. Conversely, no significant change was found for other executive functions (such as cognitive flexibility, working memory, initiation), learning, or memory. Moreover, no significant improvement on ecological measures of daily-life executive functioning was found, possibly because of the short treatment period. We replicated safety, and although very frequent, side effects were of mild intensity and comparable with previous findings.

CONCLUSIONS

This study extends the current knowledge on the effects of MPH in patients with 22q11DS. Treatment was found to be effective for core ADHD symptoms and cognitive measures of attention and inhibition.

Air Pollution-Related Brain Metal Dyshomeostasis as a Potential Risk Factor for Neurodevelopmental Disorders and Neurodegenerative Diseases

Increasing evidence links air pollution (AP) exposure to effects on the central nervous system structure and function. Particulate matter AP, especially the ultrafine (nanoparticle) components, can carry numerous metal and trace element contaminants that can reach the brain in utero and after birth. Excess brain exposure to either essential or non-essential elements can result in brain dyshomeostasis, which has been implicated in both neurodevelopmental disorders (NDDs; autism spectrum disorder, schizophrenia, and attention deficit hyperactivity disorder) and neurodegenerative diseases (NDGDs; Alzheimer’s disease, Parkinson’s disease, multiple sclerosis, and amyotrophic lateral sclerosis). This review summarizes the current understanding of the extent to which the inhalational or intranasal instillation of metals reproduces in vivo the shared features of NDDs and NDGDs, including enlarged lateral ventricles, alterations in myelination, glutamatergic dysfunction, neuronal cell death, inflammation, microglial activation, oxidative stress, mitochondrial dysfunction, altered social behaviors, cognitive dysfunction, and impulsivity. Although evidence is limited to date, neuronal cell death, oxidative stress, and mitochondrial dysfunction are reproduced by numerous metals. Understanding the specific contribution of metals/trace elements to this neurotoxicity can guide the development of more realistic animal exposure models of human AP exposure and consequently lead to a more meaningful approach to mechanistic studies, potential intervention strategies, and regulatory requirements.