Neurobiology of ADHD. Neuropharmacology. 2009;57:579-589. [PMID: 19627998 DOI: 10.1016/j.neuropharm.2009.07.026]

Risk factors for the development of problem gambling in individuals with ADHD symptoms: The mediating roles of gambling engagement and ADHD characteristics

Gambling disorder is a behavioral addiction characterized by impulsivity and problem gambling, and it often cooccurs with ADHD. This study investigated the associations between ADHD symptoms and problem gambling, focusing on the roles of various forms of gambling engagement. Based on data from the JASTIS 2024 survey, which included 29,268 valid respondents, this cross-sectional study explored how ADHD symptoms are related to the prevalence of problem gambling and specific forms of gambling engagement. Problem gambling was assessed using the Problem Gambling Severity Index, and ADHD symptoms were measured with the Japanese version of the Adult ADHD Self-Report Scale. The results revealed that 22.2 % of the participants with ADHD symptoms exhibited problem gambling, this proportion was significantly higher than that reported in the general population. Causal mediation analysis revealed that all types of gambling engagement, except for lottery, mediated the relationship between ADHD symptoms and problem gambling. Among them, bicycle racing and online casinos exhibited the strongest effects. Multiple regression analysis revealed that online casino use was the strongest predictor of problem gambling both in the general population and among individuals with ADHD symptoms. These findings suggest that individuals with ADHD characteristics increase the risk of engaging in gambling activities, particularly casino and online gambling, which have a high potential for addiction. Given the association between problem gambling and casino-related experiences, this study underscores the need for stringent regulatory measures and targeted prevention strategies, particularly as Japan considers expanding casino operations.

An Imagination - Procrastination Link? The Role of Efficacy Beliefs, Visual Imagery, and Affect in Academic Procrastination

Previous studies have established that there is a relationship between efficacy beliefs and procrastination. Theory and research on motivation suggest that visual imagery (the capacity to create vivid mental images) may be implicated in this relationship and in the general tendency to procrastinate. This study's aim was to build on prior work by examining the role of visual imagery, as well as roles of other specific personal and affective factors, in predicting academic procrastination. Self-efficacy for self regulatory behavior was observed to be the strongest predictor, predicting lower rates of academic procrastination, though this effect was significantly greater for individuals who scored higher on a measure of visual imagery. Visual imagery predicted higher levels of academic procrastination when included in a regression model with other significant factors, though this relationship did not hold for individuals who scored higher on self regulatory self-efficacy, suggesting that this self-belief may shield individuals who would otherwise be disposed to procrastination behavior. Negative affect was observed to predict higher levels of academic procrastination, contrary to a previous finding. This result highlightsthe importance of considering social contextual issues that may influence emotional states, such as those surrounding the Covid-19 epidemic, in studies of procrastination.

The effectiveness of a mindfulness-based stress reduction (MBSR) programme for parents of children with attention deficit hyperactivity disorder (ADHD): a pilot randomized controlled trial

BACKGROUND

Parents of children with attention deficit hyperactivity disorder (ADHD) often experience high levels of parental stress. This has exacerbated during the coronavirus disease 2019 (COVID-19) pandemic. The aim of this study was to examine the effectiveness of mindfulness-based stress reduction (MBSR) programme in the Chinese population, which is feasible among Chinese parents during the COVID-19 pandemic period in reducing the parental stress of parents compared with the usual care group.

METHODS

This study was designed as a pilot randomized controlled trial with single-blind repeated measures. Parents of children aged 3-12 years with a diagnosis of ADHD were recruited from the parent resource center (PRC) of a local nongovernmental organization between June and August 2022. The participants were randomly assigned to the MBSR intervention group (n = 18) or usual care group (n = 18).

RESULTS

With respect to the feasibility of the study, all 36 participants who were randomized fully completed the MBSR programme and assessments, resulting in a 100% attendance rate. 66% of the participants in the intervention group reported satisfaction with the intervention, which was helpful in reducing stress. They were willing to stay on this mindfulness-based programme in the future. The results of the repeated-measures ANOVA revealed a significant difference in self-perceived stress reduction between the groups (p < 0.001, ES = 0.192). The of within-group results revealed that the mean score of the intervention group decreased from 29.44 before the intervention to 25.50 (p < 0.001) immediately after intervention, and further decreased to 24.72 (p < 0.05) at one month after the intervention. By using the parental stress scale, the interaction effects also revealed significant differences between groups (p < 0.001, ES = 0.599). The stress level of the intervention group decreased from 74.50 before intervention, to 68.94 (p < 0.001) immediately after intervention, and further decreased to 67.50 (p < 0.05) at one month after intervention. These reports revealed statistically significant improvements in stress reduction and parental stress reduction in the intervention group.

CONCLUSION

The pilot study revealed that MBSR is feasible and acceptable for parents of children with ADHD in Chinese culture. The findings also suggested that the MBSR programme was effective in reducing parental stress and enhancing mental well-being. This study was registered in the National Library of Medicine, National Center for Biotechnology Information Clinical Trials Registry as Version 1, and the trial registration data are available as NCT06210113, 28/2/2024.

Serotonin dysfunction in ADHD

It is well accepted that attention deficit hyperactivity disorder (ADHD) is in part driven by dysfunction in the monoaminergic neurotransmitter system, but both the extent of dysfunction and possible therapeutic avenues presented by serotonergic neurotransmission is frequently overlooked. As such, we present key evidence for dysfunction in serotonergic transmission, as seen from biochemical, genetic and pharmacological perspectives. An overall deficit in serotonin availability is a common theme throughout the literature, thus this review aims to explore possible dysfunctions in the serotonin synthesis pathway which result in this reduced bioavailability, and investigate whether such dysfunctions could be loci of change in ADHD. We have identified several steps in transmission, namely the conversion of tryptophan to 5-hydroxytryptophan and its use of cofactor tetrahydrobiopterin, which could present promising avenues for development of novel clinical interventions for ADHD.

Abscisic Acid Rescues Behavior in Adult Female Mice in Attention Deficit Disorder with Hyperactivity Model of Dopamine Depletion by Regulating Microglia and Increasing Vesicular GABA Transporter Expression

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental syndrome typically diagnosed in childhood that may persist into adulthood. Its etiology encompasses both genetic and environmental factors, with genetic studies indicating catecholamine dysfunction and epidemiological evidence emphasizing neuroinflammation as a potential trigger. To investigate the roles of inflammation and development processes in ADHD, we conducted a longitudinal behavioral study using female Swiss mice with a dopamine deficit model. We explored the impact of neonatal dopaminergic lesions, treatment with abscisic acid (ABA)-an anti-inflammatory hormone-and developmental changes by comparing behavioral patterns in juvenile and adult mice. Postmortem analyses assessed neuroinflammation through microglial morphology, NLRP3, cytokine expression, and the excitatory/inhibitory (E/I) ratio in specific brain regions. Neonatal dopaminergic lesions induced hyperactivity and hypersensitivity in juvenile mice that persisted into adulthood. In adults, increased social interaction and memory impairment were observed in lesioned mice. Brain development mitigated impulsivity, while ABA treatment reduced locomotor activity, downregulated pain sensitivity, and influenced social interaction, although it did not completely resolve cognitive deficits in lesioned adult mice. In brain regions such as the anterior cingulate cortex (ACC), posterior insular cortex (pIC), and hippocampus, lesions significantly altered microglial morphology. In the ACC, lesions increased IL-1β and TNFα levels, decreased Arg1 mRNA levels, and disrupted the E/I balance. Importantly, ABA treatment restored microglial morphology, normalized IL-1β and Arg1 expression and upregulated vGAT levels. This study demonstrates that dopamine deficits lead to microglia alterations and E/I imbalance, contributing to ADHD symptoms. While some symptoms improve with brain development, targeting microglial health in specific brain regions emerges as a promising therapeutic approach for managing ADHD.

Risk of hospitalisation for first-onset psychosis or mania within a year of ADHD medication initiation in adults with ADHD

BACKGROUND

The prevalence of attention-deficit hyperactivity disorder (ADHD) drug treatment for youth and adults has been rising exponentially in Iceland over the past 15 years. The efficacy of ADHD drugs is not as strongly supported for adults as for children and adolescents, and adult use has been reported to increase the risk of psychosis or mania.

OBJECTIVE

To assess the absolute risk of hospitalisation for first-onset psychosis or mania in adults diagnosed with ADHD within 1 year of being prescribed ADHD drugs and to examine the proportional attributable risk.

METHODS

This study included all adults prescribed ADHD drugs in Iceland between 1 January 2010 and 31 December 2022. Records from the Icelandic Prescription Drug Register were linked to the Hospital Discharge Register to identify individuals who were admitted due to psychosis or mania. This risk was compared with the risk of all other first-onset hospitalisations for psychosis, mania or mixed episodes between 1 January 2018 and 31 December 2020.

FINDINGS

16 125 individuals aged 18 or older initiated ADHD drug therapy during the study period. Of those, 61 were hospitalised due to first-onset psychosis or mania within a year. This corresponds to an absolute risk of 0.38% for such an admission. The general population risk for all other first-onset hospitalisations for psychosis or mania from 2018 through 2020 for Icelanders aged 18-67 was 0.048%. The estimated relative risk was 7.99 (95% CI 6.06, 10.54), the proportional attributable risk 87.5% and the number needed to harm 302 (95% CI 271, 340). Within 1 year of hospital discharge, 69% (42/61) had been represcribed their ADHD medication, and 26.2% (11/42) of these had to be readmitted for psychosis or mania CONCLUSIONS: The risk of hospitalisation for psychosis or mania with prescription ADHD drugs is small but real among adults, and represcription is strongly associated with readmission.

CLINICAL IMPLICATIONS

Clinicians and adults diagnosed with ADHD should be aware of the association between ADHD drugs and the risk of developing psychosis or mania requiring hospitalisation in adults with ADHD.

Metabolomic and lipidomic profiling reveals convergent pathways in attention deficit hyperactivity disorder therapeutics: Insights from established and emerging treatments

Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder with unclear pathological mechanisms. ADHD is treated with both stimulant and nonstimulant medications, but their therapeutic mechanisms and impact on brain metabolites are not fully understood. This study employed an untargeted metabolomics approach with liquid chromatography mass spectrometry to investigate the pathogenesis of ADHD, as well as the effects of established and novel therapeutics. We characterized the metabolomic signatures of the adgrl3.1 mutant zebrafish ADHD model and examined the impact of methylphenidate, guanfacine, atomoxetine, and 5 novel putative therapeutics identified in a prior screen, including amlodipine. Our analysis revealed that the drugs commonly affect pathways related to amino acid and lipid metabolism, specifically involving glycine, serine, threonine, phenylalanine, lysophosphatidylcholine, and sphingomyelin. This convergence on similar metabolic targets was unexpected and suggests a broader, systemic effect of ADHD therapeutics, challenging the traditional view of distinct drug mechanisms. Amlodipine exhibited metabolic effects consistent with established treatments, indicating its potential as a viable alternative or adjunct therapy. These findings provide new insights into the metabolic underpinnings of ADHD and highlight potential targets for developing improved therapeutic strategies. SIGNIFICANCE STATEMENT: This study explores the metabolic pathways affected by attention deficit hyperactivity disorder treatments using a zebrafish adgrl3.1 mutant model. Untargeted metabolomics revealed that both established and novel attention deficit hyperactivity disorder medications influence common amino acid and lipid metabolism pathways, suggesting systemic effects. Notably, amlodipine showed similar impacts as current drugs, offering promise as an alternative therapy.

Negative Parenting Mediates the Longitudinal Association between Parental Internalizing Symptoms and Child Oppositional Symptoms

Research has pointed to both cross-sectional and longitudinal associations between parental internalizing symptoms and child externalizing symptoms. This study analyzed whether the association is mediated by negative parenting behavior in view of previous reports that both parental internalizing symptoms and child externalizing symptoms are related to parenting behaviors. Longitudinal data for the current analyses were derived from a randomized controlled trial on the efficacy of a web-assisted self-help intervention for parents of children with elevated levels of externalizing symptoms. Two different mediation models were analyzed, one using attention-deficit/hyperactivity disorder (ADHD) symptoms as the dependent variable and the other using oppositional defiant disorder (ODD) symptoms. Both models included parental internalizing symptoms as the independent variable, negative parenting behavior as a mediator, and study condition as a confounder. The longitudinal analyses support the mediating role of negative parenting behavior in the association between early parental internalizing symptoms and later child ODD symptoms.

Sub-Second Fluctuation between Top-Down and Bottom-Up Modes Distinguishes Diverse Human Brain States

Information continuously flows between regions of the human brain, exhibiting distinct patterns that dynamically shift across states of consciousness, cognitive modes, and neuropsychiatric conditions. In this study, we introduce Relative Phase Analysis (RPA), a method that leverages phase-lead/lag relationships to reveal the real-time dynamics of dominant directional patterns and their rapid transitions. We demonstrate that the human brain switches on a sub-second timescale between a top-down mode-where anterior regions drive posterior activity-and a bottom-up mode, characterized by reverse directionality. These dynamics are most pronounced during full consciousness and gradually become less distinct as awareness diminishes. Furthermore, we find from simultaneous EEG-fMRI recordings that the top-down mode is expressed when higher-order cognitive networks are more active while the bottom-up mode is expressed when sensory systems are more active. Moreover, comparisons of an attention deficit hyperactivity disorder (ADHD) inattentive cohort with typically developing individuals reveal distinct imbalances in these transition dynamics, highlighting the potential of RPA as a diagnostic biomarker. Complementing our empirical findings, a coupled-oscillator model of the structural brain network recapitulates these emergent patterns, suggesting that such directional modes and transitions may arise naturally from inter-regional neural interactions. Altogether, this study provides a framework for understanding whole-brain dynamics in real-time and identifies sub-second fluctuations in top-down versus bottom-up directionality as a fundamental mechanism underlying human information processing.

Problem-sustaining patterns: redesigning the concept of mental disorder

We propose the concept of a problem-sustaining pattern as a revision of the established concept of mental disorder. The proposed concept preserves valuable features of the established concept, such as recognition of the client's hardships and scientifically informed justification of specific interventions. However, several assumptions behind the established concept have been widely criticized, both in terms of their clinical and moral normativity as well as their ontological and empirical soundness. We argue that a focus on problem-sustainment allows us to reframe the issue of demarcation in a way that helps avoid stigmatization while clarifying the role of client agency in diagnosis. We also propose a shift toward thinking in terms of patterns of dynamic interaction, which is more in line with current developments in complexity science. We conclude the article with a discussion of further research that would be needed to address various questions raised by our proposal.

Age- and sex-dependent participation of the endocannabinoid system in locomotion and risk assessment of an ADHD rat model

Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder affecting individuals across age groups. Impairments in executive function characterize ADHD and are often associated with elevated levels of risk-taking behaviors. The endocannabinoid system plays a crucial role in modulating prefrontal cortex circuits. Here, we assessed the effects of acute pharmacological manipulation of cannabinoid CB1 and CB2 receptors on locomotion and risk assessment/anxiety-like behaviors in an ADHD animal model during adolescence and adulthood. Further, we investigated the protein levels and gene expression of endocannabinoid system components (CB1, CB2, FAAH, MAGL) in the prefrontal cortex at both ages. During adolescence, activation of cannabinoid receptors aggravated the hyperactivity and risky behaviors of the ADHD model. These behavioral traits were more evident in female rats. In adulthood, manipulation of cannabinoid receptors did not alter hyperactivity but worsened risk assessment. Overall, gene expression levels of receptors and enzymes of the endocannabinoid system were increased in the ADHD model. Our findings suggest that the endocannabinoid system may operate differently in ADHD, and manipulating this system, especially in adolescents, could exacerbate deficits in inhibitory control.

The effects and possible mechanisms of whole-body vibration on cognitive function: A narrative review

Whole-body vibration (WBV) is a physical stimulation method that transmits mechanical oscillations to the entire body through a vibration platform or device. Biokinetic and epidemiologic studies have shown that prolonged exposure to high-intensity WBV increases health risks, primarily to the lumbar spine and the nervous system connected to it. There is currently insufficient evidence to demonstrate a quantitative relationship between vibration exposure and risk of health effects. The positive effects of WBV on increasing muscle strength and improving balance and flexibility are well known, but its effects on cognitive function are more complex, with mixed findings, largely related to vibration conditions, including frequency, amplitude, and duration. Studies have shown that short-term low-frequency WBV may have a positive impact on cognitive function, demonstrates potential rehabilitation benefits in enhancing learning and memory, possibly by promoting neuromuscular coordination and enhancing neural plasticity. However, long term exposure to vibration may lead to chronic stress in nerve tissue, affecting nerve conduction efficiency and potentially interfering with neuroprotective mechanisms, thereby having a negative impact on cognitive ability, even causes symptoms such as cognitive decline, mental fatigue, decreased attention, and drowsiness. This literature review aimed to explore the effects of WBV on cognitive function and further to analyze the possible mechanisms. Based on the analysis of literatures, we came to the conclusion that the impact of WBV on cognitive function depends mainly on the frequency and duration of vibration, short-term low-frequency WBV may have a positive impact on cognitive function, while long term exposure to WBV may lead to cognitive decline, and the mechanisms may be involved in neuroinflammation, oxidative stress, synaptic plasticity, and neurotransmitter changes. This review may provide some theoretical foundations and guidance for the prevention and treatment of WBV induced cognitive impairment.

Research progress of tDCS in the treatment of ADHD

TDCS is one of the most widely used non-invasive neuromodulation techniques, which changes the excitability of local cortical tissue by applying weak continuous direct current to the scalp, effectively improves the attention and concentration of ADHD children, and improves the impulse disorder of patients, but related research is still in its infancy. Based on a review of a large number of existing literatures and an analysis of the pathogenesis and principle of ADHD, this paper summarized the research on tDCS in the treatment of ADHD in recent years from the aspects of treatment mechanism, safety and stimulation parameters, and simply compared the application of tDCS with other non-traumatic neuromodulation techniques in the treatment of ADHD. The future development direction of this technology is further discussed.

EEG Microstates in the Study of Attention-Deficit Hyperactivity Disorder: A Review of Preliminary Evidence

Attention-deficit hyperactivity disorder (ADHD) is a neurobiological condition that affects both children and adults. Microstate (MS) analyses, a data-driven approach that identifies stable patterns in EEG signals, offer valuable insights into the neurophysiological characteristics of ADHD. This review summarizes findings from 13 studies that applied MS analyses to resting-state and task-based brain activity in individuals with ADHD. Relevant research articles were retrieved from electronic databases, including PubMed, Google Scholar, Web of Science, PsychInfo, and Scopus. The reviewed studies applied MS analyses to explore brain activity differences in ADHD populations. Resting-state studies consistently reported alterations in MS organization, with increased duration (MS-D) and changes in temporal dynamics (MS-C), potentially reflecting executive dysfunctions and delayed maturation of the default mode network. Additionally, MS B demonstrated promise in distinguishing between ADHD subtypes based on differences in visual network function. Task-based and event-related potential (ERP) studies, using paradigms like the continuous performance task (CPT) or Go-NoGo Task, identified MS abnormalities (i.e., N2, P2, P3, CNV) linked to inhibition and attentional resource allocation. Preliminary evidence suggests that MS analyses hold potential for distinguishing individuals with ADHD from control groups. The integration of machine learning techniques holds promise for improving diagnostic accuracy and identifying ADHD subtypes, while MS analyses may also help monitor the effects of stimulant medications like methylphenidate by tracking neurophysiological changes. However, this review highlights the need for more standardized methodologies to enhance the generalizability and replicability of findings. These efforts will ultimately contribute to a deeper understanding of the neurobiological mechanisms that underlie ADHD.

Neurobiology of attention-deficit hyperactivity disorder: historical challenges and emerging frontiers

Extensive investigations spanning multiple levels of inquiry, from genetic to behavioural studies, have sought to unravel the mechanistic foundations of attention-deficit hyperactivity disorder (ADHD), with the aspiration of developing efficacious treatments for this condition. Despite these efforts, the pathogenesis of ADHD remains elusive. In this Review, we reflect on what has been learned about ADHD while also providing a framework that may serve as a roadmap for future investigations. We emphasize that ADHD is a highly heterogeneous disorder with multiple aetiologies that necessitates a multifactorial dimensional phenotype, rather than a fixed dichotomous conceptualization. We highlight new findings that suggest a more brain-wide, 'global' view of the disorder, rather than the traditional localizationist framework, which asserts that a limited set of brain regions or networks underlie ADHD. Last, we underscore how underpowered studies that have aimed to associate neurobiology with ADHD phenotypes have long precluded the field from making progress. However, a new age of ADHD research with refined phenotypes, advanced methods, creative study designs and adequately powered investigations is beginning to put the field on a good footing. Indeed, the field is at a promising juncture to advance the neurobiological understanding of ADHD and fulfil the promise of clinical utility.

The Relationship Between Prenatal, Perinatal, and Postnatal Factors and ADHD: The Role of Nutrition, Diet, and Stress

Attention-Deficit Hyperactive Disorder (ADHD) is a neurobehavioral syndrome affecting children aged 6-17 with symptoms manifesting before age 12. ADHD presents heterogeneously and is associated with various psychiatric disorders. The cause remains elusive, but genetic and environmental factors, brain region maturation delays, and neurotransmitter dysregulation are implicated. Effective treatment requires a multi-disciplinary approach, primarily involving pharmacological and behavioral intervention. Stimulants like methylphenidate and amphetamines are first-line medications, but non-stimulants may be considered for some patients. However, stimulants face challenges related to misuse, dependence, and long-term tolerability issues. The etiology of ADHD involved genetic predisposition, environmental influences, and prenatal, perinatal, and postnatal factors. Prenatal causes encompass maternal diet, alcohol consumption, viral infections, and stress. Postnatal factors include head trauma, meningitis, toxin, nutritional deficiencies, as well as iodine deficiency and hypothyroidism. The gut microbiome's role in ADHD is emerging, influencing neurodevelopment through microbiota-gut-brain axis. Understanding these diverse etiological factors is essential for comprehensive ADHD management.

Is there a link between peripheral inflammation and blood brain barrier integrity in children with attention-deficit/hyperactivity disorder? A case-control study

BACKGROUND

Claudin-5 is a vital constituent of tight junctions, which are critical elements of the blood-brain barrier. In people with neuropsychiatric disorders, peripheral inflammation is often found, although it is less common in healthy populations. The objective of this study was to examine the relationship between Claudin-5, peripheral immune cells, and the severity of symptoms in children with attention deficit hyperactivity disorder (ADHD).

METHODS

The study included a cohort of 33 children diagnosed with ADHD and 29 control subjects, all aged between 5 and 12 years. The intensity of ADHD symptoms was evaluated using Conner's questionnaire, which the parents completed. Each kid had serum level measurements of Claudin-5 and a complete blood count in order to establish a correlation with symptoms of ADHD.

RESULTS

Serum Claudin-5 levels are lower in the ADHD group compared to the control group; median (IQR) = 30.94 (4-137) and 44.12 (4-223.3) respectively (p = 0.69). The levels of neutrophils and neutrophil/lymphocyte ratio are significantly higher in ADHD than in controls (p = 0.011 and 0.015, respectively). Lymphocytes have a significant positive correlation with ADHD symptoms severity, namely, total Conner's scale and inattention (p = 0.021 and 0.004 respectively), while NLR has a significant negative correlation with total Conner's score and impulsivity (p = 0.046, p = 0.038), also a negative correlation yet not significant between serum Claudin-5 level and total Conner's score, hyperactivity, impulsivity, and inattention. Neutrophils were found to have a significant positive linear regression with Claudin-5 (p = 0.023).

CONCLUSION

These results revealed that BBB integrity is affected in ADHD children, as claudin-5 levels were found to be lower in children with ADHD, lymphocytes were found to be associated with increased ADHD symptoms severity, and NLR was associated with decreased symptoms severity, which may be via the positive effects of increased neutrophils on Claudin-5 levels.

Rhynchophylline Alleviates Hyperactivity and Cognitive Flexibility Impairment Associated With Inhibition of Inflammatory Responses in Mice That Partly Lack the Dopamine Transporter Protein

BACKGROUND AND AIMS

Rhynchophylline (RHY) can alleviate some cognitive flexibility impairment and stereotyped behavior for attention-deficit hyperactivity disorder (ADHD) and Tourette syndrome (TS) patients as one of a key extract and an active ingredient in Ningdong granule (NDG), which is a Traditional Chinese medicine (TCM) preparation widely used in the treatment of ADHD and TS children in China; however, the underlying mechanism is not well understood. Therefore, this study aimed to evaluate how RHY alleviates hyperactivity and cognitive flexibility impairment while inhibiting inflammatory responses in mice that partly lack dopamine transporter protein (DAT- mice).

METHODS

Male DAT- mice were randomly divided into the RHY group (n = 8) and administered RHY (30 mg/kg) in the DAT- group (n = 8) and administered saline (i.p., 10 mL/kg) in wild-type (WT) mice as the WT control group (n = 8). Hyperactivity and cognitive flexibility impairment were evaluated by the open field test (OFT) and the Morris water maze (MWM) test. The levels of the inflammatory factors of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in cortical homogenates were tested by enzyme-linked immunosorbent assays (ELISA) after 8 weeks of treatment with RHY. In vitro, primary microglia and astrocytes extracted from the cortices of DAT- neonatal mice and WT neonatal mice were treated with lipopolysaccharide (LPS) (1 mg/mL) to induce neuroinflammatory responses and with RHY (20 mM) for 48 h. The levels of the inflammatory factors TNF-α, IL-1β, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX2) in the culture medium were measured at 6 h, 24 h, and 48 h after treatment with LPS and RHY.

RESULTS

RHY ameliorated hyperactivity and cognitive flexibility impairment in DAT- mice and inhibited the expression of the inflammatory factors TNF-α, IL-1β, iNOS, and COX-2 in microglia and astrocytes in vitro, and also inhibited the expression of TNF-α and IL-1β in cortical homogenates after 8 weeks of treatment.

CONCLUSION

RHY improved hyperactivity and cognitive flexibility impairment through inhibiting inflammatory responses in DAT- mice.

Modeling Functional Brain Networks for ADHD via Spatial Preservation-Based Neural Architecture Search

Modeling functional brain networks (FBNs) for attention deficit hyperactivity disorder (ADHD) has sparked significant interest since the abnormal functional connectivity is discovered in certain functional magnetic resonance imaging (fMRI)-based brain regions compared to typical developmental control (TC) individuals. However, existing models for modeling FBNs generally use dimensionality reduction techniques to process the high dimensional input data, which results in confusion and an inaccurate representation of voxel interactions between spatially close brain regions, causing misdiagnosis of the disease. To address these issues, we propose a spatial preservation-based neural architecture search (SP-NAS) for FBNs modeling in ADHD. The main work includes three-fold: 1) A spatial preservation module is designed to embed original spatial information into dimensionality reduction data, addressing the challenge of a large number of parameters in the original data and mitigating disease misdiagnosis resulting from voxel confusion between different brain regions caused by dimensionality reduction. 2) A search space using more suitable search operations is constructed to efficiently extract spatial-temporal interaction characteristics of fMRI data in ADHD while narrowing the search space. 3) Cross-regional association differences between ADHD and TC groups are explored for ADHD auxiliary diagnosis since the abnormal activation regions of ADHD relative to TC on the brain regions and the abnormal connectivity between the lesion brain regions are identified. Model validation results on the ADHD-200 dataset show that the FBNs obtained from SP-NAS not only achieve competitive results in ADHD diagnosis but also reveal abnormal connections in the lesion regions of ADHD consistent with clinical diagnosis.

The relationship between structural properties of frontal cortical regions and response inhibition in 6-14-year-old children

Development of attentional skills and inhibitory control rely on maturational changes in the brain across childhood and youth. However, both brain anatomy and different components of attention and inhibition show notable individual variation. Research on ADHD and inhibitory training and control have shown that variations in the thickness and surface area of particularly inferior cortical structures are associated with attentional control. However, the intricacies of how the development of inhibitory control is associated with the anatomical variations beyond the general age- and gender-dependent differences have not been resolved. Here, we sought to address these questions by quantifying the cortical thickness and surface area in frontal cortical regions and inhibitory control using the stop signal task performance in 6-14-year-old children. Our results showed that the thickness of the left medial orbitofrontal cortex and the surface area of the left caudal anterior cingulate were associated with the inhibitory performance, beyond the variance that could be explained by the subjects' age and gender. The results highlight the importance of factoring in anatomical variations when following attentional development and the importance of evaluating multiple anatomical measures when aiming to link the properties of cortical structures with variations in cognitive performance.

A feasibility study of a Smart screening tool for people at risk of mental health issues: Response rate, and sociodemographic and clinical factors

BACKGROUND

The use of Smart Screening tools to identify mental health problems has scarce empirical data on their effectiveness. This study aims to explore the response rate of patients to this tool and observe their socio-demographic and healthcare characteristics, and the tool's ability to detect potential mental health diagnoses.

METHODS

The study employed an online survey within patient portal from patients of four teaching hospitals in Madrid. The sample included 8749 patients, comprising 66.77 % females and 31.21 % middle-aged adults.

RESULTS

60.56 % responded to the Smart Screening tool. Respondents were found to be predominantly middle-aged women who had been contacted by mental health services multiple times but had not exhibited suicidal behaviour. These patients demonstrated a higher appointment attendance rate and generated low healthcare costs. The tool identified probable low depression and mild anxiety (72.16 %), and individuals aged 50-65 exhibited higher levels of mental health problems, such as psychosis and suicidality, although these results were not all significant regarding previous mental health diagnoses.

LIMITATIONS

The Smart Screening tool collects anonymous online data through short questionnaires to apply sophisticated algorithms and determine probable mental health diagnoses.

CONCLUSIONS

The response rate to the Smart Screening tool was higher than in previous studies. The respondents' profile was middle-aged and older women with moderate mental health problems, although suicidality was also identified. Future research should focus on those who did not respond to the tool and explore the link between previous psychiatric diagnoses and the accuracy of the Smart Screening tool.

Long-life triclosan exposure induces ADHD-like behavior in rats via prefrontal cortex dopaminergic deficiency

In recent years, exposure to triclosan (TCS) has been linked to an increase in psychiatric disorders. Nonetheless, the precise mechanisms of this occurrence remain elusive. Therefore, this study developed a long-life TCS-exposed rat model, an SH-SY5Y cell model, and an atomoxetine hydrochloride (ATX) treatment model to explore and validate the neurobehavioral mechanisms of TCS from multiple perspectives. In the long-life TCS-exposed model, pregnant rats received either 0 mg/kg (control) or 50 mg/kg TCS by oral gavage throughout pregnancy, lactation, and weaning of their offspring (up to 8 weeks old). In the ATX treatment model, weanling rats received daily injections of either 0 mg/kg (control) or 3 mg/kg ATX via intraperitoneal injection until they reached 8 weeks old. Unlike the TCS model, ATX exposure only occurred after the pups were weaned. The results indicated that long-life TCS exposure led to attention-deficit hyperactivity disorder (ADHD)-like behaviors in male offspring rats accompanied by dopamine-related mRNA and protein expression imbalances in the prefrontal cortex (PFC). Moreover, in vitro experiments also confirmed these findings. Mechanistically, TCS reduced dopamine (DA) synthesis, release, and transmission, and increased reuptake in PFC, thereby reducing synaptic gap DA levels and causing dopaminergic deficits. Additional experiments revealed that increased DA concentration in PFC by ATX effectively alleviated TCS-induced ADHD-like behavior in male offspring rats. These findings suggest that long-life TCS exposure causes ADHD-like behavior in male offspring rats through dopaminergic deficits. Furthermore, ATX treatment not only reduce symptoms in the rats, but also reveals valuable insights into the neurotoxic mechanisms induced by TCS.

Computational Analysis and Experimental Data Exploring the Role of Hesperetin in Ameliorating ADHD and SIRT1/Nrf2/Keap1/OH-1 Signaling

Attention deficit hyperactivity disorder (ADHD) manifests as poor attention, hyperactivity, as well as impulsive behaviors. Hesperetin (HSP) is a citrus flavanone with strong antioxidant and anti-inflammatory activities. The present study aimed to test hesperetin efficacy in alleviating experimental ADHD in mice and its influence on hippocampal neuron integrity and sirtuin 1 (SIRT1) signaling. An in silico study was performed to test the related proteins. Groups of mice were assigned as control, ADHD model, ADHD/HSP (25 mg/kg), and ADHD/HSP (50 mg/kg). ADHD was induced by feeding with monosodium glutamate (0.4 g/kg, for 8 weeks) and assessed by measuring the motor and attentive behaviors (open filed test, Y-maze test, and marble burying test), histopathological examination of the whole brain tissues, and estimation of inflammatory markers. The in-silico results indicated the putative effects of hesperetin on ADHD by allowing the integration and analysis of large-scale genomic, transcriptomic, and proteomic data. The in vivo results showed that ADHD model mice displayed motor hyperactivity and poor attention in the behavioral tasks and shrank neurons at various hippocampal regions. Further, there was a decline in the mRNA expression and protein levels for SIRT1, the erythroid 2-related factor-2 (Nrf2), kelch like ECH associated protein 1 (Keap1) and hemeoxygenase-1 (OH-1) proteins. Treatment with HSP normalized the motor and attentive behaviors, prevented hippocampal neuron shrinkage, and upregulated SIRT1/Nrf2/Keap1/OH-1 proteins. Taken together, HSP mainly acts by its antioxidant potential. However, therapeutic interventions with hesperetin or a hesperetin-rich diet can be suggested as a complementary treatment in ADHD patients but cannot be suggested as an ADHD treatment per se as it is a heterogeneous and complex disease.

Use of donepezil for neurocognitive recovery after brain injury in adult and pediatric populations: a scoping review

There are few pharmacologic options for the treatment of cognitive deficits associated with traumatic brain injury in pediatric patients. Acetylcholinesterase inhibitors such as donepezil have been evaluated in adult patients after traumatic brain injury, but relatively less is known about the effect in pediatric populations. The goal of this review is to identify knowledge gaps in the efficacy and safety of acetylcholinesterase inhibitors as a potential adjuvant treatment for neurocognitive decline in pediatric patients with traumatic brain injury. Investigators queried PubMed to identify literature published from database inception through June 2023 describing the use of donepezil in young adult traumatic brain injury and pediatric patients with predefined conditions. Based on preselected search criteria, 340 unique papers were selected for title and abstract screening. Thirty-two records were reviewed in full after eliminating preclinical studies and papers outside the scope of the project. In adult traumatic brain injury, we review results from 14 papers detailing 227 subjects where evidence suggests donepezil is well tolerated and shows both objective and patient-reported efficacy for reducing cognitive impairment. In children, 3 papers report on 5 children recovering from traumatic brain injury, showing limited efficacy. An additional 15 pediatric studies conducted in populations at risk for cognitive dysfunction provide a broader look at safety and efficacy in 210 patients in the pediatric age group. Given its promise for efficacy in adults with traumatic brain injury and tolerability in pediatric patients, we believe further study of donepezil for children and adolescents with traumatic brain injury is warranted.

Molecular Mechanisms behind Obesity and Their Potential Exploitation in Current and Future Therapy

Obesity is a chronic disease caused primarily by the imbalance between the amount of calories supplied to the body and energy expenditure. Not only does it deteriorate the quality of life, but most importantly it increases the risk of cardiovascular diseases and the development of type 2 diabetes mellitus, leading to reduced life expectancy. In this review, we would like to present the molecular pathomechanisms underlying obesity, which constitute the target points for the action of anti-obesity medications. These include the central nervous system, brain-gut-microbiome axis, gastrointestinal motility, and energy expenditure. A significant part of this article is dedicated to incretin-based drugs such as GLP-1 receptor agonists (e.g., liraglutide and semaglutide), as well as the brand new dual GLP-1 and GIP receptor agonist tirzepatide, all of which have become "block-buster" drugs due to their effectiveness in reducing body weight and beneficial effects on the patient's metabolic profile. Finally, this review article highlights newly designed molecules with the potential for future obesity management that are the subject of ongoing clinical trials.

The Microbiome in Child and Adolescent Psychiatry

Recent research has increasingly emphasized the function of the microbiome in human health. The gut microbiome is essential for digesting food and seems to play a vital role in mental health as well. This review briefly overviews the gut microbiome and its interplay with the central nervous system. We then summarize some of the latest findings on the possible role of the microbiome in psychiatric disorders in children and adolescents. In particular, we focus on autism spectrum disorder, attention-deficit/hyperactivity disorder, anorexia nervosa, bipolar disorder, and major depressive disorder. Although the role of microbiota in mental development and health still needs to be researched intensively, it has become increasingly apparent that the impact of microbiota must be considered to better understand psychiatric disorders.

Symptom-guided multimodal neuroimage fusion patterns in children with attention-deficit/hyperactivity disorder and its potential "brain structure-function-cognition-behavior" pathological pathways

The "brain-cognition-behavior" process is an important pathological pathway in children with attention-deficit/hyperactivity disorder (ADHD). Symptom guided multimodal neuroimaging fusion can capture behaviorally relevant and intrinsically linked structural and functional features, which can help to construct a systematic model of the pathology. Analyzing the multimodal neuroimage fusion pattern and exploring how these brain features affect executive function (EF) and leads to behavioral impairment is the focus of this study. Based on gray matter volume (GMV) and fractional amplitude of low frequency fluctuation (fALFF) for 152 ADHD and 102 healthy controls (HC), the total symptom score (TO) was set as a reference to identify co-varying components. Based on the correlation between the identified co-varying components and EF, further mediation analysis was used to explore the relationship between brain image features, EF and clinical symptoms. This study found that the abnormalities of GMV and fALFF in ADHD are mainly located in the default mode network (DMN) and prefrontal-striatal-cerebellar circuits, respectively. GMV in ADHD influences the TO through Metacognition Index, while fALFF in HC mediates the TO through behavior regulation index (BRI). Further analysis revealed that GMV in HC influences fALFF, which further modulates BRI and subsequently affects hyperactivity-impulsivity score. To conclude, structural brain abnormalities in the DMN in ADHD may affect local brain function in the prefrontal-striatal-cerebellar circuit, making it difficult to regulate EF in terms of inhibit, shift, and emotional control, and ultimately leading to hyperactive-impulsive behavior.

Enhancement of visual dominance effects at the response level in children with attention-deficit/hyperactivity disorder

Previous studies have widely demonstrated that individuals with attention-deficit/hyperactivity disorder (ADHD) exhibit deficits in conflict control tasks. However, there is limited evidence regarding the performance of children with ADHD in cross-modal conflict processing tasks. The current study aimed to investigate whether children with ADHD have poor conflict control, which has an impact on sensory dominance effects at different levels of information processing under the influence of visual similarity. A total of 82 children aged 7 to 14 years, including 41 children with ADHD and 41 age- and sex-matched typically developing (TD) children, were recruited. We used the 2:1 mapping paradigm to separate levels of conflict, and the congruency of the audiovisual stimuli was divided into three conditions. In C trials, the target stimulus and the distractor stimulus were identical, and the bimodal stimuli corresponded to the same response keys. In PRIC trials, the distractor stimulus differed from the target stimulus and did not correspond to any response keys. In RIC trials, the distractor stimulus differed from the target stimulus, and the bimodal stimuli corresponded to different response keys. Therefore, we explicitly differentiated cross-modal conflict into a preresponse level (PRIC > C), corresponding to the encoding process, and a response level (RIC > PRIC), corresponding to the response selection process. Our results suggested that auditory distractors caused more interference during visual processing than visual distractors caused during auditory processing (i.e., typical auditory dominance) at the preresponse level regardless of group. However, visual dominance effects were observed in the ADHD group, whereas no visual dominance effects were observed in the TD group at the response level. A possible explanation is that the increased interference effects due to visual similarity and children with ADHD made it more difficult to control conflict when simultaneously confronted with incongruent visual and auditory inputs. The current study highlights how children with ADHD process cross-modal conflicts at multiple levels of information processing, thereby shedding light on the mechanisms underlying ADHD.

The C886T Mutation in the Th Gene Reduces the Activity of Tyrosine Hydroxylase in the Mouse Brain

Tyrosine hydroxylase (TH) catalyzes hydroxylation of L-tyrosine to L-3,4-dihydroxyphenylalanine, the initial and rate-limiting step in the synthesis of dopamine, noradrenaline, and adrenaline. Mutations in the human TH gene are associated with hereditary motor disorders. The common C886T mutation identified in the mouse Th gene results in the R278H substitution in the enzyme molecule. We investigated the impact of this mutation on the TH activity in the mouse midbrain. The TH activity in the midbrain of Mus musculus castaneus (CAST) mice homozygous for the 886C allele was higher compared to C57BL/6 and DBA/2 mice homozygous for the 886T allele. Notably, this difference in the enzyme activity was not associated with changes in the Th gene mRNA levels and TH protein content. Analysis of the TH activity in the midbrain in mice from the F2 population obtained by crossbreeding of C57BL/6 and CAST mice revealed that the 886C allele is associated with a high TH activity. Moreover, this allele showed complete dominance over the 886T allele. However, the C886T mutation did not affect the levels of TH protein in the midbrain. These findings demonstrate that the C886T mutation is a major genetic factor determining the activity of TH in the midbrain of common laboratory mouse strains. Moreover, it represents the first common spontaneous mutation in the mouse Th gene whose influence on the enzyme activity has been demonstrated. These results will help to understand the role of TH in the development of adaptive and pathological behavior, elucidate molecular mechanisms regulating the activity of TH, and explore pharmacological agents for modulating its function.

Selenoprotein T, a potential treatment of attention-deficit/hyperactivity disorder and comorbid pain in neonatal 6-OHDA lesioned mice

pathological pain and Attention-deficit/hyperactivity disorder (ADHD) are two complex multifactorial syndromes. The comorbidity of ADHD and altered pain perception is well documented in children, adolescents, and adults. According to pathophysiological investigations, the dopaminergic system's dysfunction provides a common basis for ADHD and comorbid pain. Growing evidence suggests that oxidative stress may be crucial in both pathologies. Recent studies revealed that a small peptide encompassing the redox-active site of selenoprotein T (PSELT), protects dopaminergic neurons and fibers as well as lesioned nerves in animal models. The current study aims to examine the effects of PSELT treatment on ADHD-like symptoms and pain sensitivity, as well as the role of catecholaminergic systems in these effects. Our results demonstrated that intranasal administration of PSELT reduced the hyperactivity in the open field, decreased the impulsivity displayed by 6-OHDA-lesioned male mice in the 5-choice serial reaction time task test and improved attentional performance. In addition, PSELT treatment significantly increased the nociception threshold in both normal and inflammatory conditions. Furthermore, anti-hyperalgesic activity was antagonized with sulpiride pre-treatment, but not by phentolamine, or propranolol pre-treatments. The present study suggests that PSELT reduces the severity of ADHD symptoms in mice and possesses potent antinociceptive effects which could be related to the involvement of D2/D3 dopaminergic receptors.

Sports preferences in children and adolescents in psychiatric care-evaluation of a new questionnaire

Introduction

As part of an exploratory and hypothesis-generating study, we developed the Sports Preference Questionnaire (SPOQ) to survey the athletic behavior of mentally ill children and adolescents, subjectively assessed physical fitness and perceived psychological effects of physical activity.

Methods

In a department of child and adolescent psychiatry, we classified 313 patients (6-18 years) according to their primary psychiatric diagnosis. The patients or-in the parental version of the questionnaire-their parents reported their sport preferences on the SPOQ. As possibly influential factors, we also assessed the frequency of physical activity, the importance of a trainer, coping with everyday life through physical activity, and subjectively perceived physical fitness.

Results

One in 3 patients (32.4%) stated that they were not physically active. Patients diagnosed with eating disorders reported, on average, a notably high frequency (median of 3 h/week) and degree of coping with daily life through physical activity (median of 5 on a 6-point Likert scale). Patients with anxiety disorders and depression had the lowest self-perception of physical fitness (mean value of 3.1 or 3.7 on an interval scala from 0 to 9). The presence of a trainer was generally considered not important, except for ADHD patients (median of 3 on a 6-point Likert scale).

Conclusion

The SPOQ is sensitive for differential effects of core child and adolescent disorders as well as for main covariates influencing the complex association between physical activity and emotional and behavioral disorders in children and adolescents. Based on this pilot study, we discussed the need for an efficacy study to measure the effects of sports therapy.

Effects of acute and chronic methylphenidate on prepulse inhibition: A sex difference study in Wistar rats

BACKGROUND

The utilization of methylphenidate (MPH) is experiencing a notable surge within the adult population. This growth can be attributed to two key factors: its recreational and cognitive enhancement purposes, as well as the rising prevalence of ADHD diagnoses within this population. This study examined acute and chronic oral MPH effects on attention in male and female Wistar rats. To this end, we used a prepulse inhibition (PPI) task, which is widely used to assess psychoactive drug effects in both humans and rodents. This task allowed us to evaluate changes in attention by analyzing sensorimotor gating associated with stimulus selection process.

METHODS

Animals were administered a clinically relevant dose of MPH (5 mg/kg) daily for seven days. The estrous cycle phases of the female rats were measured during behavioral sessions. The PPI task was conducted 20 min after drug administration on day 1 (acute), day 7 (chronic), and 48 h post-treatment.

RESULTS

Results indicated that both acute and chronic MPH treatment impaired PPI expression in male rats, but not in female rats, regardless of their estrous cycle phase. Furthermore, a differential effect of chronic MPH treatment on the PPI task was found in male rats. Specifically, on the seventh treatment day, the PPI effect was observed when animals undertook the PPI task for the first time but was impaired in those animals in which the initial PPI session occurred under the acute influence of the drug (day 1).

CONCLUSIONS

These findings suggest that the impact of MPH on sensorimotor gating responses may vary based on sex and task experience, possibly leading to state-dependent effects in healthy individuals.

Cortical gradient perturbation in attention deficit hyperactivity disorder correlates with neurotransmitter-, cell type-specific and chromosome- transcriptomic signatures

AIMS

This study aimed to illuminate the neuropathological landscape of attention deficit hyperactivity disorder (ADHD) by a multiscale macro-micro-molecular perspective from in vivo neuroimaging data.

METHODS

The "ADHD-200 initiative" repository provided multi-site high-quality resting-state functional connectivity (rsfc-) neuroimaging for ADHD children and matched typically developing (TD) cohort. Diffusion mapping embedding model to derive the functional connectome gradient detecting biologically plausible neural pattern was built, and the multivariate partial least square method to uncover the enrichment of neurotransmitomic, cellular and chromosomal gradient-transcriptional signatures of AHBA enrichment and meta-analytic decoding.

RESULTS

Compared to TD, ADHD children presented connectopic cortical gradient perturbations in almost all the cognition-involved brain macroscale networks (all pBH <0.001), but not in the brain global topology. As an intermediate phenotypic variant, such gradient perturbation was spatially enriched into distributions of GABAA/BZ and 5-HT2A receptors (all pBH <0.01) and co-varied with genetic transcriptional expressions (e.g. DYDC2, ATOH7, all pBH <0.01), associated with phenotypic variants in episodic memory and emotional regulations. Enrichment models demonstrated such gradient-transcriptional variants indicated the risk of both cell-specific and chromosome- dysfunctions, especially in enriched expression of oligodendrocyte precursors and endothelial cells (all pperm <0.05) as well enrichment into chromosome 18, 19 and X (pperm <0.05).

CONCLUSIONS

Our findings bridged brain macroscale neuropathological patterns to microscale/cellular biological architectures for ADHD children, demonstrating the neurobiologically pathological mechanism of ADHD into the genetic and molecular variants in GABA and 5-HT systems as well brain-derived enrichment of specific cellular/chromosomal expressions.

Co-occurrence of Attention-Deficit/Hyperactivity Disorder and Septo-Optic Dysplasia: A Neurodevelopmental Case Report

Septo-optic dysplasia (SOD) is a rare congenital disorder characterized by optic nerve hypoplasia, brain midline structure anomalies, and hypothalamic-pituitary axis hypoplasia. This case report aims to highlight the association between SOD and neurodevelopmental disorders, focusing on attention-deficit/hyperactivity disorder (ADHD) in addition to the well-established link with autism spectrum disorder (ASD). A six-year-old male diagnosed with SOD presented with behavioral concerns, including attention and impulse control issues. A comprehensive psychological evaluation confirmed the diagnosis of ADHD and ruled out ASD. Ophthalmological assessments were integral to understanding the patient's condition. This case underscores the importance of recognizing neurodevelopmental disorders in individuals with SOD, with a particular focus on the less common association with ADHD. The co-occurrence of these conditions underscores the complexity of neurodevelopmental disorders and the need for comprehensive evaluation and management. Collaboration between ophthalmologists and mental health specialists is crucial for addressing the diverse needs of these patients. Early identification and intervention for ADHD are essential for optimal developmental outcomes. This case underscores the necessity for further research to elucidate the relationship between SOD and ADHD, emphasizing the importance of holistic patient care and interdisciplinary collaboration in managing individuals with SOD spectrum conditions.

Intensity-dependent effects of tDCS on motor learning are related to dopamine

Non-invasive brain stimulation techniques, such as transcranial direct current stimulation (tDCS), are popular methods for inducing neuroplastic changes to alter cognition and behaviour. One challenge for the field is to optimise stimulation protocols to maximise benefits. For this to happen, we need a better understanding of how stimulation modulates cortical functioning/behaviour. To date, there is increasing evidence for a dose-response relationship between tDCS and brain excitability, however how this relates to behaviour is not well understood. Even less is known about the neurochemical mechanisms which may drive the dose-response relationship between stimulation intensities and behaviour. Here, we examine the effect of three different tDCS stimulation intensities (1 mA, 2 mA, 4 mA anodal motor cortex tDCS) administered during the explicit learning of motor sequences. Further, to assess the role of dopamine in the dose-response relationship between tDCS intensities and behaviour, we examined how pharmacologically increasing dopamine availability, via 100 mg of levodopa, modulated the effect of stimulation on learning. In the absence of levodopa, we found that 4 mA tDCS improved and 1 mA tDCS impaired acquisition of motor sequences relative to sham stimulation. Conversely, levodopa reversed the beneficial effect of 4 mA tDCS. This effect of levodopa was no longer evident at the 48-h follow-up, consistent with previous work characterising the persistence of neuroplastic changes in the motor cortex resulting from combining levodopa with tDCS. These results provide the first direct evidence for a role of dopamine in the intensity-dependent effects of tDCS on behaviour.

Monitoring Changes in TMS-Evoked EEG and EMG Activity During 1 Hz rTMS of the Healthy Motor Cortex

Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive brain stimulation technique capable of inducing neuroplasticity as measured by changes in peripheral muscle electromyography (EMG) or electroencephalography (EEG) from pre-to-post stimulation. However, temporal courses of neuromodulation during ongoing rTMS are unclear. Monitoring cortical dynamics via TMS-evoked responses using EMG (motor-evoked potentials; MEPs) and EEG (transcranial-evoked potentials; TEPs) during rTMS might provide further essential insights into its mode of action - temporal course of potential modulations. The objective of this study was to first evaluate the validity of online rTMS-EEG and rTMS-EMG analyses, and second to scrutinize the temporal changes of TEPs and MEPs during rTMS. As rTMS is subject to high inter-individual effect variability, we aimed for single-subject analyses of EEG changes during rTMS. Ten healthy human participants were stimulated with 1,000 pulses of 1 Hz rTMS over the motor cortex, while EEG and EMG were recorded continuously. Validity of MEPs and TEPs measured during rTMS was assessed in sensor and source space. Electrophysiological changes during rTMS were evaluated with model fitting approaches on a group- and single-subject level. TEPs and MEPs appearance during rTMS was consistent with past findings of single pulse experiments. Heterogeneous temporal progressions, fluctuations or saturation effects of brain activity were observed during rTMS depending on the TEP component. Overall, global brain activity increased over the course of stimulation. Single-subject analysis revealed inter-individual temporal courses of global brain activity. The present findings are in favor of dose-response considerations and attempts in personalization of rTMS protocols.

The role of irrational beliefs in the relationship between attention deficit hyperactivity disorder (ADHD) symptoms and disordered eating in two general student samples

Attention deficit hyperactivity disorder (ADHD) symptoms are associated with disordered eating and negative mood. The purpose of this study was to examine whether irrational beliefs mediate this relationship along with previously reported mediators such as depression and impulsivity. Irrational beliefs trigger negative automatic thoughts which are believed, in cognitive behavior therapies, to be a source of psychopathology. Challenges brought about by symptoms of ADHD may lead to habitual emotion-eliciting thought patterns which, in turn, could lead to negative mood and disordered eating. Undergraduate students (N = 127) completed online questionnaires assessing ADHD symptoms and disordered eating and several potential mediators including irrational beliefs, depression, impulsivity, interoceptive accuracy, and reward responsiveness. The results, which were replicated in a second study (N = 254), indicated that irrational beliefs and depression mediated the relationship between ADHD symptoms and disordered eating. In the second study, impulsivity due to negative urgency was also a mediator. These findings support the theory that the symptoms of ADHD lead to enhancement of irrational beliefs, depression, and negative urgency which are linked to disordered eating.

Assessment of the glymphatic function in children with attention-deficit/hyperactivity disorder

OBJECTIVES

Whether the alternation of the glymphatic system exists in neurodevelopmental disease still remains unclear. In this study, we investigated structural and functional changes in the glymphatic system in the treatment-naïve attention-deficit/hyperactivity disorder (ADHD) children by quantitatively measuring the Virchow-Robin spaces (VRS) volume and diffusion tensor image-analysis along the perivascular space (DTI-ALPS).

METHODS

Forty-seven pediatric ADHD patients and 52 age- and gender-matched typically developing (TD) children were recruited in this prospective study. The VRS volume was calculated using a semi-automated approach in axial T2-weighted images. Diffusivities along the x-, y-, and z-axes in the projection, association, and subcortical neural fiber areas were measured. The ALPS index, a ratio that accentuated water diffusion along the perivascular space, was calculated. The Mann-Whitney U test was used to compare the quantitative parameters; Pearson's correlation was used to analyze the correlation with clinical symptoms.

RESULTS

The cerebral VRS volume (mean, 15.514 mL vs. 11.702 mL) and the VRS volume ratio in the ADHD group were larger than those in the TD group (all p < 0.001). The diffusivity along the x-axis in association fiber area and ALPS index were significantly smaller in the ADHD group vs. TD group (mean, 1.40 vs.1.59, p < 0.05 after false discovery rate adjustment). Besides, the ALPS index was related to inattention symptoms of ADHD (r =  - 0.323, p < 0.05).

CONCLUSIONS

Our study suggests that the glymphatic system alternation may participate in the pathogenesis of ADHD, which may be a new research direction for exploring the mechanisms of psycho-behavioral developmental disorders. Moreover, the VRS volume and ALPS index could be used as the metrics for diagnosing ADHD.

CLINICAL RELEVANCE STATEMENT

Considering the potential relevance of the glymphatic system for exploring the mechanisms of attention deficit/hyperactivity, the Virchow-Robin spaces volume and the analysis along the perivascular space index could be used as additional metrics for diagnosing the disorder.

KEY POINTS

• Increased Virchow-Robin space volume and decreased analysis along the perivascular space index were found in the treatment-naïve attention-deficit/hyperactivity disorder children. • The results of this study indicate that the glymphatic system alternation may have a valuable role in the pathogenesis of attention-deficit/hyperactivity disorder. • The analysis along the perivascular space index is correlated with inattention symptoms of attention-deficit/hyperactivity disorder children.

Methylphenidate for treating fatigue in palliative cancer care - effect and side effects in real-world data from a palliative care unit

BACKGROUND

Methylphenidate can be used for the treatment of cancer-related fatigue (CRF), although randomized controlled trials have shown conflicting results. The aim of this study was to use 'real-world' data to evaluate the effect and side effects of using methylphenidate in palliative cancer care with a focus on the late palliative phase and dose-response.

METHOD

A retrospective review of medical records from a palliative care unit in Sweden was performed to evaluate the effect and adverse events (AEs) of using methylphenidate to treat CRF. Univariable and multivariable regression was performed and odds ratio (OR) calculated. Adjustments were made for sex, age, cancer type, dose and starting treatment <4 weeks before death.

RESULTS

Of the 2,419 screened patients, 112 had been treated with methylphenidate for CRF. The treatment was assessed as being effective in 51 patients (46%). Twenty-six patients (23%) experienced AEs that were generally mild, including anxiety, palpitations, and insomnia. Patients starting the treatment <4 weeks before death (n = 54) were less likely to have an effect from treatment compared to those starting earlier; adjusted OR 0.24 (95% CI 0.10-0.55). Doses of 20 mg and above were well-tolerated and had a higher frequency of effect in the crude data but not after adjustment for confounding factors.

CONCLUSION

Methylphenidate is generally effective and well-tolerated for the treatment of CRF in palliative care. However, patients with a short life expectancy (<4 weeks) seem to benefit less from the treatment regardless of age, cancer type and dose.

Non-human contributions to personality neuroscience: From fish through primates - a concluding editorial overview

This special issue attempts to integrate personality, psychopathology, and neuroscience as means to improve understanding of specific traits and trait structures in humans. The key strategy is to dive into comparative research using a range of species to provide simple models. This strategy has, as its foundation, the fact that the most basic functions, and their supporting neural systems, are highly conserved in evolution. The papers collected in the issue show that, from fish, through rats, to primates, the homologies in brain systems and underlying functions (despite species-specific forms of expression) allow simpler cases to provide insights into the neurobiology behind more complex ones including human. Our introductory editorial paper to this special issue took a bottom-up approach, starting with the genetics of conserved brain systems and working up to cognition. Here, we deconstruct the different aspects of personality, progressing from more complex ones in primates to least complex in fish. With the primate section, we summarize papers that discuss the factors that contribute to sociability in primates and how they apply to healthy and pathological human personality traits. In the rat section, the focus is driven by psychopathology and the way that "high" strains selected for extreme behaviors can illuminate the neurobiology of motivated responses to environmental cues. The section on fish summarizes papers that look into the most fundamental emotional reactions to the environment that are governed by primitive and conserved brain structures. This raises metatheoretical questions on the nature of traits and to a section that asks "which animals have personalities." We believe that the issue as a whole provides a nuanced answer to this question and shines a new, comparative, light on the interpretation of personality structure and the effects on it of evolution.

Expected changes in parenting after an online parent training for ADHD

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) is a common neurodevelopmental disorder in children and adolescents. Treatments for this population should be multidisciplinary and must be initiated as early as possible. Non-pharmacological interventions for ADHD include psychoeducation, parent behavioural training programs and school interventions and accommodations. In response to the COVID-19 pandemic, we developed an online version of a combined psychoeducation and behavioural training program to facilitate access to mental health treatment and ensure continuity of care.

OBJECTIVE

The study assessed the acceptability of this online parent training program, among parents and caretakers of children and adolescents with ADHD.

METHODS

The program consisted of ten online sessions over the course of two consecutive days (five sessions a day). Satisfaction, usefulness and general comments about the program were assessed with open-ended questions and visual-analogous scales. Parents/caretakers' use of strategies to manage behavioural problems was assessed using the Parenting and Family Adjustment Scales.

RESULTS

A total of 206 parents participated in the online program 175 of whom completed the evaluation. Participants were satisfied with the content of the program. More than half of participants had already started using strategies included in the program. The engagement was high and no major obstacles were identified other than some internet connection issues.

DISCUSSION

In our survey, online delivery was described as more convenient, and participants were satisfied with the content of the program finding it beneficial for their child. Despite this, some difficulties in implementing new strategies were observed. Online BTP increased access to the BTP programs while being effective on ADHD symptoms and behavioural disturbances.

CONCLUSIONS

With these measures, we hope to improve engagement in online psychoeducation and behavioural therapy programs. Future research evaluating online behavioural training programs should focus on ways to make them more accessible and adaptable to families' obstacles.

Using rodent data to elucidate dopaminergic mechanisms of ADHD: Implications for human personality

An altered behavioral response to positive reinforcement has been proposed to be a core deficit in attention deficit hyperactivity disorder (ADHD). The spontaneously hypertensive rat (SHR), a congenic animal strain, displays a similarly altered response to reinforcement. The presence of this genetically determined phenotype in a rodent model allows experimental investigation of underlying neural mechanisms. Behaviorally, the SHR displays increased preference for immediate reinforcement, increased sensitivity to individual instances of reinforcement relative to integrated reinforcement history, and a steeper delay of reinforcement gradient compared to other rat strains. The SHR also shows less development of incentive to approach sensory stimuli, or cues, that predict reward after repeated cue-reward pairing. We consider the underlying neural mechanisms for these characteristics. It is well known that midbrain dopamine neurons are initially activated by unexpected reward and gradually transfer their responses to reward-predicting cues. This finding has inspired the dopamine transfer deficit (DTD) hypothesis, which predicts certain behavioral effects that would arise from a deficient transfer of dopamine responses from actual rewards to reward-predicting cues. We argue that the DTD predicts the altered responses to reinforcement seen in the SHR and individuals with ADHD. These altered responses to reinforcement in turn predict core symptoms of ADHD. We also suggest that variations in the degree of dopamine transfer may underlie variations in personality dimensions related to altered reinforcement sensitivity. In doing so, we highlight the value of rodent models to the study of human personality.

Attention Deficit Hyperactivity Disorder (ADHD) and Polyphenols: A Systematic Review

Polyphenols are natural compounds also contained in daily consumed foods that show their efficacy in different clinical fields. Both pre-clinical and clinical studies demonstrated that polyphenols may manage neuroinflammation and oxidative stress processes tightly connected to neurodegenerative diseases and mental disorders. Thus, a neuroinflammatory state may influence the neurotransmitters pathways, such as the noradrenergic, glutamatergic, serotoninergic, and, in particular, dopaminergic ones, whose impairment is strongly associated with attention deficit hyperactivity disorder (ADHD). Therefore, the aim of the present systematic review is to provide an overview of the clinical outcomes' changes following ADHD treatment with polyphenols alone and in combination with the traditional drugs. This review was conducted according to PRISMA guidelines and recorded on PROSPERO with the number CRD42023438491; PubMed, Scopus, and Web of Science were used as search-engines to lead our research until June 2023. The inclusion criteria were articles written in English, including clinical, placebo-controlled, and case-control trials. We excluded reviews, metanalyses, background articles, and papers published in other languages. To avoid any bias, Rayyan software (COPYRIGHT © 2022 RAYYAN) was used to organize the work and manage the literature review. After screening, 10 studies were included, with a total of 556 patients that met the established inclusion criteria. The data obtained from these studies showed that polyphenols rebalanced oxidative stress pathways through different mechanisms, are effective for the treatment of ADHD both alone and in combination with traditional drugs, and are able to reduce symptoms as well as the side effects related to the use of conventional therapies. Finally, a positive effect of using polyphenols for ADHD prevention could be hypothesized.

Inflammatory biotype of ADHD is linked to chronic stress: a data-driven analysis of the inflammatory proteome

The association between Attention Deficit Hyperactivity Disorder (ADHD) and low-grade inflammation has been explored in children but rarely in adults. Inflammation is characteristic of some, but not all, patients with ADHD and might be influenced by ADHD medication but also lifestyle factors including nutrition, smoking, and stress. It is also still unclear if any specific symptoms are related to inflammation. Therefore, we assessed 96 inflammatory proteins in a deeply phenotyped cohort of 126 adult ADHD participants with a stable medication status using OLINK technology. A data-based, unsupervised hierarchical clustering method could identify two distinct biotypes within the 126 ADHD participants based on their inflammatory profile: a higher inflammatory potential (HIP) and a lower inflammatory protein potential (LIP) group. Biological processes that differed strongest between groups were related to the NF-κB pathway, chemokine signaling, IL-17 signaling, metabolic alterations, and chemokine attraction. A comparison of sample characteristics revealed that the HIP group was more likely to have higher levels of chronic stress (p < 0.001), a higher clinical global impression scale score (p = 0.030), and a higher risk for suicide (p = 0.032). Medication status did not influence protein levels significantly (p ≥ 0.074), but psychotropic co-medication (p ≤ 0.009) did. In conclusion, our data suggest the presence of two distinct biotypes in adults with ADHD. Higher levels of inflammatory proteins in ADHD are linked to higher levels of chronic perceived stress in a linear fashion. Further research on inflammation in adults with ADHD should take stress levels into account.

Attention Deficit Hyperactivity Disorder in Adults With Migraine

INTRODUCTION

Several studies have shown increased occurrence of migraine in ADHD patients. However, there is less evidence on whether migraine patients also have a higher ADHD frequency. The aim of this paper is determining whether the prevalence of ADHD symptoms or impulsivity is higher in patients with episodic migraine.

METHODS

An observational cohort study has been conducted. Patients with episodic migraine were included. The ADHD Rating scale, the Adult ADHD Self-Report Scale, and the scale of impulsiveness of Plutchik were used.

RESULTS

The mean value of inattention, hyperactivity and impulsivity scores on the ADHD scale was 5 ± 3.8 in cases and 2.7 ± 2.2 in controls (p < .00001), 4 ± 3.2 in cases and 2.5 ± 2.4 in controls (p = .000621) and 2 ± 1.5 in cases and 1.1 ± 1 in controls (p = .000407), respectively.

CONCLUSION

Adults with migraine have a higher prevalence of ADHD symptoms. This should be considered when assessing these patients.

The Activity of Adenosine Deaminase and Dipeptidyl Peptidase IV in Children With Attention Deficit Hyperactivity Disorder

OBJECTIVE

In this study, to investigate the place of T cell-mediated immunity in the etiology of ADHD, for which we do not have enough information; we aimed to investigate the activity of DPP IV and ADA, which are T cell-related enzymes, and the relationship of these enzymes with ADHD symptoms in children with ADHD.

METHODS

Twenty-seven children aged 6 to 12 years with a diagnosis of attention deficit hyperactivity disorder and 27 children aged 6 to 12 years without any psychiatric disease were included in the study.

RESULTS

While serum ADA and DPP-IV activity were found to be statistically significantly higher in the group with ADHD. There was no statistically significant correlation between serum ADA and DPP-IV activities and CTRS-R-L and CPRS-R-L in both groups.

CONCLUSION

We think that T cell mediated inflammation may play a role in the etiology of ADHD due to changes in ADA and DPP-IV levels in children.

ADHD in narcolepsy: A closer look at prevalence and ties

The reported prevalence of attention deficit hyperactivity disorder (ADHD) in narcolepsy varies considerably, while the associated factors remain inadequately established. A systematic search of studies published in PubMed, EMBASE, and the Cochrane Library was performed from inception to March 2023. Ten studies with 839 patients with narcolepsy were included in the study. Utilizing a random effects model, the pooled prevalence of ADHD in narcolepsy was 25% (95% CI, 14-38%). Notably, patients with narcolepsy type 2 showed a significantly higher prevalence of ADHD than that of narcolepsy type 1 (46% vs. 20%, p = 0.045). Furthermore, the rate of ADHD was notably elevated in narcolepsy compared with the healthy controls (odds ratio 9.59, 95% CI, 4.06-22.63, p < 0.001). Several factors such as excessive daytime sleepiness (EDS), fatigue, insomnia severity, and the quality of life were significantly associated with ADHD in narcolepsy (all ps < 0.05). These findings highlight the importance of monitoring and managing ADHD in narcolepsy, and provide a clue to help reducing ADHD by intervening in these associated factors.

Predictors for quality of life in older adults: network analysis on cognitive and neuropsychiatric symptoms

BACKGROUND

Quality of life (QoL) of older adults has become a pivotal concern of the public and health system. Previous studies found that both cognitive decline and neuropsychiatric symptoms (NPS) can affect QoL in older adults. However, it remains unclear how these symptoms are related to each other and impact on QoL. Our aim is to investigate the complex network relationship between cognitive and NPS symptoms in older adults, and to further explore their association with QoL.

METHODS

A cross-sectional study was conducted in a sample of 389 older individuals with complaints of memory decline. The instruments included the Neuropsychiatric Inventory, the Mini Mental State Examination, and the 36-item Short Form Health Survey. Data was analyzed using network analysis and mediation analysis.

RESULTS

We found that attention and agitation were the variables with the highest centrality in cognitive and NPS symptoms, respectively. In an exploratory mediation analysis, agitation was significantly associated with poor attention (β = -0.214, P < 0.001) and reduced QoL (β = -0.137, P = 0.005). The indirect effect of agitation on the QoL through attention was significant (95% confidence interval (CI) [-0.119, -0.035]). Furthermore, attention served as a mediator between agitation and QoL, accounting for 35.09% of the total effect.

CONCLUSIONS

By elucidating the NPS-cognition-QoL relationship, the current study provides insights for developing rehabilitation programs among older adults to ensure their QoL.

Exploring the Potential "Brain-Cognition-Behavior" Relationship in Children With ADHD Based on Resting-State Brain Local Activation and Functional Connectivity

OBJECTIVE

Exploring how abnormal brain function in children with ADHD affects executive function and ultimately leads to behavioral impairment provides a theoretical basis for clinically targeted neurotherapy and cognitive training.

METHOD

Amplitude of low frequency fluctuations (ALFF), regional homogeneity (ReHo), and seed-based FC were analyzed in 53 ADHD and 52 healthy controls. The "brain-cognition-behavior" relationship was further explored using mediation analysis.

RESULTS

ADHD showed abnormal local activation in the middle temporal gyrus (MTG), inferior occipital gyrus and inferior frontal gyrus (IFG) and reduced FC between the IFG and the cerebellum. ADHD diagnosis may affect ALFF of MTG and further modulate shift and finally affect inattentive symptoms. It may also affect the total symptoms through the FC of the IFG with the cerebellum.

CONCLUSION

ADHD showed extensive spontaneous activity abnormalities and frontal-cerebellar FC impairments. Localized functional abnormalities in the MTG may affect the shift in EF, resulting in attention deficit behavior.

Associations between neonatal jaundice and autism spectrum disorder or attention deficit hyperactivity disorder: Nationwide population based cohort study

BACKGROUND/PURPOSE

Neonatal jaundice might result brain insults. Both autistic spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD) are developmental disorders, which might result from early brain injury at neonatal period. We aimed to explore the association between neonatal jaundice treated with phototherapy and the ASD or ADHD.

METHODS

This retrospective nationwide population cohort study was based on a nationally representative database of Taiwan, and neonates born from 2004 to 2010 were enrolled. All eligible infants were divided into 4 groups, without jaundice, jaundice with no treatment, jaundice with simple phototherapy only and jaundice with intensive phototherapy or blood exchange transfusion (BET). Each infant was follow-up until the date of incident primary outcomes, death, or 7-year-old, whichever occurred first. Primary outcomes were ASD, ADHD. Using cox proportional hazard model to analyze their associations.

RESULTS

In total, 118,222 infants with neonatal jaundice were enrolled, including diagnosed only (7260), simple phototherapy (82,990), intensive phototherapy or BET (27,972 infants). The cumulative incidences of ASD in each group was 0.57%, 0.81%, 0.77%, and 0.83%, respectively. The cumulative incidences of ADHD in each group was 2.83%, 4.04%, 3.52% and 3.48%, respectively. Jaundice groups were significantly associated with ASD, ADHD, or either one, even after all other extraneous maternal and neonatal variables were adjusted. After stratification, the associations were still existed in subgroup with birth weights ≥2500 grams and in male subgroup.

CONCLUSION

Neonatal jaundice correlated with the ASD and ADHD. The associations were significant in infants of both sexes and with birth weights larger than 2500 grams.