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1.
Semin Cell Dev Biol ; 144: 67-76, 2023 07 30.
Article in English | MEDLINE | ID: mdl-36115764

ABSTRACT

The use of antidepressants during pregnancy benefits the mother's well-being, but the effects of such substances on neurodevelopment remain poorly understood. Moreover, the consequences of early exposure to antidepressants may not be immediately apparent at birth. In utero exposure to selective serotonin reuptake inhibitors (SSRIs) has been related to developmental abnormalities, including a reduced white matter volume. Several reports have observed an increased incidence of autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD) after prenatal exposure to SSRIs such as sertraline, the most widely prescribed SSRI. The advent of human-induced pluripotent stem cell (hiPSC) methods and assays now offers appropriate tools to test the consequences of such compounds for neurodevelopment in vitro. In particular, hiPSCs can be used to generate cerebral organoids - self-organized structures that recapitulate the morphology and complex physiology of the developing human brain, overcoming the limitations found in 2D cell culture and experimental animal models for testing drug efficacy and side effects. For example, single-cell RNA sequencing (scRNA-seq) and electrophysiological measurements on organoids can be used to evaluate the impact of antidepressants on the transcriptome and neuronal activity signatures in developing neurons. While the analysis of large-scale transcriptomic data depends on dimensionality reduction methods, electrophysiological recordings rely on temporal data series to discriminate statistical characteristics of neuronal activity, allowing for the rigorous analysis of the effects of antidepressants and other molecules that affect the developing nervous system, especially when applied in combination with relevant human cellular models such as brain organoids.


Subject(s)
Autism Spectrum Disorder , Selective Serotonin Reuptake Inhibitors , Pregnancy , Female , Infant, Newborn , Animals , Humans , Selective Serotonin Reuptake Inhibitors/pharmacology , Autism Spectrum Disorder/drug therapy , Autism Spectrum Disorder/epidemiology , Antidepressive Agents/pharmacology , Antidepressive Agents/therapeutic use , Brain , Organoids
2.
Am J Hum Genet ; 109(3): 417-432, 2022 03 03.
Article in English | MEDLINE | ID: mdl-35139346

ABSTRACT

Genome-wide association studies (GWASs) have revolutionized human genetics, allowing researchers to identify thousands of disease-related genes and possible drug targets. However, case-control status does not account for the fact that not all controls may have lived through their period of risk for the disorder of interest. This can be quantified by examining the age-of-onset distribution and the age of the controls or the age of onset for cases. The age-of-onset distribution may also depend on information such as sex and birth year. In addition, family history is not routinely included in the assessment of control status. Here, we present LT-FH++, an extension of the liability threshold model conditioned on family history (LT-FH), which jointly accounts for age of onset and sex as well as family history. Using simulations, we show that, when family history and the age-of-onset distribution are available, the proposed approach yields statistically significant power gains over LT-FH and large power gains over genome-wide association study by proxy (GWAX). We applied our method to four psychiatric disorders available in the iPSYCH data and to mortality in the UK Biobank and found 20 genome-wide significant associations with LT-FH++, compared to ten for LT-FH and eight for a standard case-control GWAS. As more genetic data with linked electronic health records become available to researchers, we expect methods that account for additional health information, such as LT-FH++, to become even more beneficial.


Subject(s)
Genetic Predisposition to Disease , Genome-Wide Association Study , Age of Onset , Case-Control Studies , Genome-Wide Association Study/methods , Humans , Medical History Taking
3.
Am J Hum Genet ; 109(8): 1436-1457, 2022 08 04.
Article in English | MEDLINE | ID: mdl-35907405

ABSTRACT

ADGRL1 (latrophilin 1), a well-characterized adhesion G protein-coupled receptor, has been implicated in synaptic development, maturation, and activity. However, the role of ADGRL1 in human disease has been elusive. Here, we describe ten individuals with variable neurodevelopmental features including developmental delay, intellectual disability, attention deficit hyperactivity and autism spectrum disorders, and epilepsy, all heterozygous for variants in ADGRL1. In vitro, human ADGRL1 variants expressed in neuroblastoma cells showed faulty ligand-induced regulation of intracellular Ca2+ influx, consistent with haploinsufficiency. In vivo, Adgrl1 was knocked out in mice and studied on two genetic backgrounds. On a non-permissive background, mice carrying a heterozygous Adgrl1 null allele exhibited neurological and developmental abnormalities, while homozygous mice were non-viable. On a permissive background, knockout animals were also born at sub-Mendelian ratios, but many Adgrl1 null mice survived gestation and reached adulthood. Adgrl1-/- mice demonstrated stereotypic behaviors, sexual dysfunction, bimodal extremes of locomotion, augmented startle reflex, and attenuated pre-pulse inhibition, which responded to risperidone. Ex vivo synaptic preparations displayed increased spontaneous exocytosis of dopamine, acetylcholine, and glutamate, but Adgrl1-/- neurons formed synapses in vitro poorly. Overall, our findings demonstrate that ADGRL1 haploinsufficiency leads to consistent developmental, neurological, and behavioral abnormalities in mice and humans.


Subject(s)
Autism Spectrum Disorder , Intellectual Disability , Neurodevelopmental Disorders , Receptors, G-Protein-Coupled , Receptors, Peptide , Adult , Animals , Autism Spectrum Disorder/genetics , Disease Models, Animal , Haploinsufficiency/genetics , Humans , Intellectual Disability/genetics , Mice , Mice, Knockout , Neurodevelopmental Disorders/genetics
4.
Cereb Cortex ; 34(6)2024 Jun 04.
Article in English | MEDLINE | ID: mdl-38858839

ABSTRACT

Children with attention-deficit/hyperactivity disorder show deficits in processing speed, as well as aberrant neural oscillations, including both periodic (oscillatory) and aperiodic (1/f-like) activity, reflecting the pattern of power across frequencies. Both components were suggested as underlying neural mechanisms of cognitive dysfunctions in attention-deficit/hyperactivity disorder. Here, we examined differences in processing speed and resting-state-Electroencephalogram neural oscillations and their associations between 6- and 12-year-old children with (n = 33) and without (n = 33) attention-deficit/hyperactivity disorder. Spectral analyses of the resting-state EEG signal using fast Fourier transform revealed increased power in fronto-central theta and beta oscillations for the attention-deficit/hyperactivity disorder group, but no differences in the theta/beta ratio. Using the parameterization method, we found a higher aperiodic exponent, which has been suggested to reflect lower neuronal excitation-inhibition, in the attention-deficit/hyperactivity disorder group. While fast Fourier transform-based theta power correlated with clinical symptoms for the attention-deficit/hyperactivity disorder group only, the aperiodic exponent was negatively correlated with processing speed across the entire sample. Finally, the aperiodic exponent was correlated with fast Fourier transform-based beta power. These results highlight the different and complementary contribution of periodic and aperiodic components of the neural spectrum as metrics for evaluation of processing speed in attention-deficit/hyperactivity disorder. Future studies should further clarify the roles of periodic and aperiodic components in additional cognitive functions and in relation to clinical status.


Subject(s)
Attention Deficit Disorder with Hyperactivity , Brain , Cognition , Electroencephalography , Humans , Child , Attention Deficit Disorder with Hyperactivity/physiopathology , Male , Female , Brain/physiopathology , Cognition/physiology , Fourier Analysis , Brain Waves/physiology , Theta Rhythm/physiology , Beta Rhythm/physiology
5.
J Neurosci ; 43(41): 6898-6908, 2023 10 11.
Article in English | MEDLINE | ID: mdl-37666665

ABSTRACT

Prevailing frameworks propose that a key feature of attention-deficit/hyperactivity disorder (ADHD) is lower motivation. An important component of motivation is the willingness to engage in cognitively or physically effortful behavior. However, the degree to which effort sensitivity is impaired in ADHD has rarely been tested, and the efficacy of stimulant medication in ameliorating any such impairments is unclear. Here, we tested 20 individuals with ADHD (11 males, 9 females) who were managed with amphetamine-based medication (dexamfetamine, lisdexamfetamine), and 24 controls (8 males, 16 females). Individuals with ADHD were tested over two counterbalanced sessions, ON and OFF their usual amphetamine-based medication. In each session, participants performed an effort-based decision-making task, in which they were required to choose how much cognitive or physical effort they were willing to engage in return for reward. Our results revealed three main findings. First, individuals with ADHD had lower motivation relative to controls to invest effort in both the cognitive and physical domains. Second, amphetamine increased motivation uniformly across both domains. Finally, the net effect of amphetamine treatment was to mostly restore motivation across both domains of effort relative to healthy controls. These data provide clear evidence for a heightened sensitivity to both cognitive and physical effort in ADHD, and reveal the efficacy of amphetamine-based drugs in restoring effort sensitivity to levels similar to controls. These findings confirm the existence of reduced motivational drive in ADHD, and more broadly provide direct causal evidence for a domain-general role of catecholamines in motivating effortful behavior.SIGNIFICANCE STATEMENT A core feature of attention-deficit/hyperactivity disorder (ADHD) is thought to be a heightened aversion to effort. Surprisingly, however, the degree to which effort sensitivity is impaired in ADHD has rarely been tested. More broadly, the relative efficacy of catecholamines in motivating the investment of cognitive and physical effort is unclear. We tested 20 individuals with ADHD ON and OFF amphetamines, and compared their behavior on an effort-based decision-making task to 24 controls. When tested OFF medication, the ADHD group was less cognitively and physically motivated than controls. However, amphetamines led to a comparable increase in motivation across both domains. This demonstrates the efficacy of catecholamines in facilitating domain-general effort, and highlights the broader potential of such drugs to treat disorders of motivation.


Subject(s)
Attention Deficit Disorder with Hyperactivity , Central Nervous System Stimulants , Male , Female , Humans , Attention Deficit Disorder with Hyperactivity/drug therapy , Motivation , Amphetamines/pharmacology , Amphetamines/therapeutic use , Lisdexamfetamine Dimesylate/pharmacology , Lisdexamfetamine Dimesylate/therapeutic use , Catecholamines , Central Nervous System Stimulants/pharmacology , Central Nervous System Stimulants/therapeutic use
6.
Ann Hum Genet ; 2024 Apr 16.
Article in English | MEDLINE | ID: mdl-38624263

ABSTRACT

To investigate the association of attention-deficit/hyperactivity disorder (ADHD) with the 48-base pair (bp) variable number of tandem repeats (VNTR) in exon 3 of the dopamine receptor D4 (DRD4) gene, we genotyped 240 ADHD patients and their parents from Hong Kong. The 4R allele was most common, followed by 2R. We examined association between the 2R allele (relative to 4R) and ADHD by Transmission Disequilibrium Test (TDT). The odds ratio (OR) (95% confidence interval) was 0.90 (0.64-1.3). The p-value was 0.6. Examining subgroups revealed nominally significant association of 2R with inattentive ADHD: OR = 0.33 (0.12-0.92) and p = 0.03. Because our study used TDT analysis, we meta-analyzed the association of 2R with ADHD in Asians (1329 patient alleles), revealing results similar to ours: OR = 0.97 (0.80-1.2) and p = 0.8. To examine the association of 2R with inattentive ADHD, we meta-analyzed all studies (regardless of analysis type or ethnicity, in order to increase statistical power): 702 patient alleles, 1420 control alleles, OR = 0.81 (0.57-1.1) and p = 0.2. Overall, there is no evidence of association between ADHD and the 2R allele, but the suggestive association with the inattentive type warrants further investigation.

7.
Eur J Neurosci ; 59(7): 1567-1584, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38314648

ABSTRACT

The spontaneously hypertensive rat (SHR) is a selectively bred animal strain that is frequently used to model attention-deficit hyperactivity disorder (ADHD) because of certain genetically determined behavioural characteristics. To test the hypothesis that the characteristically altered response to positive reinforcement in SHRs may be due to altered phasic dopamine response to reward, we measured phasic dopamine signals in the SHRs and Sprague Dawley (SD) rats using in vivo fast-scan cyclic voltammetry. The effects of the dopamine reuptake inhibitor, methylphenidate, on these signals were also studied. Phasic dopamine signals during the pairing of a sensory cue with electrical stimulation of midbrain dopamine neurons were significantly smaller in the SHRs than in the SD rats. Over repeated pairings, the dopamine response to the sensory cue increased, whereas the response to the electrical stimulation of dopamine neurons decreased, similarly in both strains. However, the final amplitude of the response to the sensory cue after pairing was significantly smaller in SHRs than in the SD rats. Methylphenidate increased responses to sensory cues to a significantly greater extent in the SHRs than in the SD rats, due largely to differences in the low dose effect. At a higher dose, methylphenidate increased responses to sensory cues and electrical stimulation similarly in SHRs and SD rats. The smaller dopamine responses may explain the reduced salience of reward-predicting cues previously reported in the SHR, whereas the action of methylphenidate on the cue response suggests a potential mechanism for the therapeutic effects of low-dose methylphenidate in ADHD.


Subject(s)
Central Nervous System Stimulants , Methylphenidate , Rats , Animals , Methylphenidate/pharmacology , Methylphenidate/therapeutic use , Rats, Inbred SHR , Dopamine , Rats, Inbred WKY , Rats, Sprague-Dawley , Disease Models, Animal , Central Nervous System Stimulants/pharmacology
8.
Development ; 148(20)2021 10 15.
Article in English | MEDLINE | ID: mdl-34557899

ABSTRACT

The inhibitory GABAergic system in the brain is involved in the etiology of various psychiatric problems, including autism spectrum disorders (ASD), attention deficit hyperactivity disorder (ADHD) and others. These disorders are influenced not only by genetic but also by environmental factors, such as preterm birth, although the underlying mechanisms are not known. In a translational hyperoxia model, exposing mice pups at P5 to 80% oxygen for 48 h to mimic a steep rise of oxygen exposure caused by preterm birth from in utero into room air, we documented a persistent reduction of cortical mature parvalbumin-expressing interneurons until adulthood. Developmental delay of cortical myelin was observed, together with decreased expression of oligodendroglial glial cell-derived neurotrophic factor (GDNF), a factor involved in interneuronal development. Electrophysiological and morphological properties of remaining interneurons were unaffected. Behavioral deficits were observed for social interaction, learning and attention. These results demonstrate that neonatal oxidative stress can lead to decreased interneuron density and to psychiatric symptoms. The obtained cortical myelin deficit and decreased oligodendroglial GDNF expression indicate that an impaired oligodendroglial-interneuronal interplay contributes to interneuronal damage.


Subject(s)
Brain Injuries/metabolism , GABAergic Neurons/metabolism , Hyperoxia/metabolism , Interneurons/metabolism , Parvalbumins/metabolism , Premature Birth/metabolism , Rodentia/metabolism , Animals , Cell Line , Cognition/physiology , Disease Models, Animal , Glial Cell Line-Derived Neurotrophic Factor/metabolism , Male , Mice , Mice, Inbred C57BL , Mice, Transgenic , Oligodendroglia/metabolism , Social Behavior
9.
BMC Med ; 22(1): 223, 2024 Jun 03.
Article in English | MEDLINE | ID: mdl-38831366

ABSTRACT

BACKGROUND: The trajectory of attention-deficit hyperactivity disorder (ADHD) symptoms in children and adolescents, encompassing descending, stable, and ascending patterns, delineates their ADHD status as remission, persistence or late onset. However, the neural and genetic underpinnings governing the trajectory of ADHD remain inadequately elucidated. METHODS: In this study, we employed neuroimaging techniques, behavioral assessments, and genetic analyses on a cohort of 487 children aged 6-15 from the Children School Functions and Brain Development project at baseline and two follow-up tests for 1 year each (interval 1: 1.14 ± 0.32 years; interval 2: 1.14 ± 0.30 years). We applied a Latent class mixed model (LCMM) to identify the developmental trajectory of ADHD symptoms in children and adolescents, while investigating the neural correlates through gray matter volume (GMV) analysis and exploring the genetic underpinnings using polygenic risk scores (PRS). RESULTS: This study identified three distinct trajectories (ascending-high, stable-low, and descending-medium) of ADHD symptoms from childhood through adolescence. Utilizing the linear mixed-effects (LME) model, we discovered that attention hub regions served as the neural basis for these three developmental trajectories. These regions encompassed the left anterior cingulate cortex/medial prefrontal cortex (ACC/mPFC), responsible for inhibitory control; the right inferior parietal lobule (IPL), which facilitated conscious focus on exogenous stimuli; and the bilateral middle frontal gyrus/precentral gyrus (MFG/PCG), accountable for regulating both dorsal and ventral attention networks while playing a crucial role in flexible modulation of endogenous and extrinsic attention. Furthermore, our findings revealed that individuals in the ascending-high group exhibited the highest PRS for ADHD, followed by those in the descending-medium group, with individuals in the stable-low group displaying the lowest PRS. Notably, both ascending-high and descending-medium groups had significantly higher PRS compared to the stable-low group. CONCLUSIONS: The developmental trajectory of ADHD symptoms in the general population throughout childhood and adolescence can be reliably classified into ascending-high, stable-low, and descending-medium groups. The bilateral MFG/PCG, left ACC/mPFC, and right IPL may serve as crucial brain regions involved in attention processing, potentially determining these trajectories. Furthermore, the ascending-high pattern of ADHD symptoms exhibited the highest PRS for ADHD.


Subject(s)
Attention Deficit Disorder with Hyperactivity , Humans , Attention Deficit Disorder with Hyperactivity/genetics , Attention Deficit Disorder with Hyperactivity/physiopathology , Child , Adolescent , Male , Female , Magnetic Resonance Imaging , Brain/diagnostic imaging , Brain/growth & development , Gray Matter/diagnostic imaging , Gray Matter/pathology , Neuroimaging , Cohort Studies
10.
J Neurosci Res ; 102(4): e25323, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38553948

ABSTRACT

Previously, we reported that prenatal exposure to high corticosterone induced attention-deficit hyperactivity disorder (ADHD)-like behaviors with cognitive deficits after weaning. In the present study, cellular mechanisms underlying cortisol-induced cognitive dysfunction were investigated using rat pups (Corti.Pups) born from rat mothers that were repetitively injected with corticosterone during pregnancy. In results, Corti.Pups exhibited the failure of behavioral memory formation in the Morris water maze (MWM) test and the incomplete long-term potentiation (LTP) of hippocampal CA1 neurons. Additionally, glutamatergic excitatory postsynaptic currents (EPSCs) were remarkably suppressed in Corti.Pups compared to normal rat pups. Incomplete LTP and weaker EPSCs in Corti.Pups were attributed to the delayed postsynaptic development of CA1 neurons, showing a higher expression of NR2B subunits and lower expression of PSD-95 and BDNF. These results indicated that the prenatal treatment with corticosterone to elevate cortisol level might potently downregulate the BDNF-mediated signaling critical for the synaptic development of hippocampal CA1 neurons during brain development, and subsequently, induce learning and memory impairment. Our findings suggest a possibility that the prenatal dysregulation of cortisol triggers the epigenetic pathogenesis of neurodevelopmental psychiatric disorders, such as ADHD and autism.


Subject(s)
Corticosterone , Hydrocortisone , Humans , Pregnancy , Female , Rats , Animals , Corticosterone/pharmacology , Brain-Derived Neurotrophic Factor/metabolism , Maze Learning/physiology , Hippocampus/metabolism , Long-Term Potentiation , Neurons/metabolism , Memory Disorders/metabolism
11.
Proc Biol Sci ; 291(2017): 20222584, 2024 Feb 28.
Article in English | MEDLINE | ID: mdl-38378153

ABSTRACT

All mobile organisms forage for resources, choosing how and when to search for new opportunities by comparing current returns with the average for the environment. In humans, nomadic lifestyles favouring exploration have been associated with genetic mutations implicated in attention deficit hyperactivity disorder (ADHD), inviting the hypothesis that this condition may impact foraging decisions in the general population. Here we tested this pre-registered hypothesis by examining how human participants collected resources in an online foraging task. On every trial, participants chose either to continue to collect rewards from a depleting patch of resources or to replenish the patch. Participants also completed a well-validated ADHD self-report screening assessment at the end of sessions. Participants departed resource patches sooner when travel times between patches were shorter than when they were longer, as predicted by optimal foraging theory. Participants whose scores on the ADHD scale crossed the threshold for a positive screen departed patches significantly sooner than participants who did not meet this criterion. Participants meeting this threshold for ADHD also achieved higher reward rates than individuals who did not. Our findings suggest that ADHD attributes may confer foraging advantages in some environments and invite the possibility that this condition may reflect an adaptation favouring exploration over exploitation.


Subject(s)
Attention Deficit Disorder with Hyperactivity , Humans , Attention Deficit Disorder with Hyperactivity/diagnosis , Reward , Life Style , Self Report
12.
J Pediatr ; 269: 113997, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38432293

ABSTRACT

OBJECTIVE: To evaluate trends of attention-deficit/hyperactivity disorder (ADHD) diagnosis rates among children aged 5-17 years over the past decade (2010-2021) and to investigate whether there have been differences in temporal changes based on race and ethnicity, sex, or income. STUDY DESIGN: Childhood ADHD diagnosis was ascertained from electronic health records using International Classification of Diseases ninth revision (314.xx) and International Classification of Diseases tenth revision (F90.x) codes. Data were stratified by child's sex, race and ethnicity, and household income, and rates of ADHD were estimated before and after adjustment for potential confounders. RESULTS: The overall ADHD diagnosis rates increased from 3.5% in 2010 to 4.0% in 2021. ADHD diagnosis was most prevalent among White children (6.1%), then Black (4.6%), Other/multiple (3.7%), Hispanic (3.1%), and Asian/Pacific Islander (PI) (1.7%). ADHD was also highly prevalent among boys (73.3%) or family income≥$70,000 (50.0%). ADHD diagnosis increased among Black (4.2% to 5.1%), Hispanic (2.8% to 3.6%), and Asian/PI children (1.5% to 2.0%) but remained stable for White (6.2% to 6.1%) and Other/multiple race/ethnic children (3.7% to 3.7%). Increases in the prevalence among girls were also observed. CONCLUSION: The prevalence of ADHD in children has risen with the largest increases observed for Black, Hispanic, and Asian/PI children. Rates among less affluent families and girls have also been increasing, narrowing the gaps in diagnosis rates previously observed. These increases may reflect improvements in screening and provision of care among demographics where ADHD has been historically underdiagnosed.


Subject(s)
Attention Deficit Disorder with Hyperactivity , Delivery of Health Care, Integrated , Humans , Attention Deficit Disorder with Hyperactivity/epidemiology , Attention Deficit Disorder with Hyperactivity/diagnosis , Child , Male , Female , Adolescent , Child, Preschool , California/epidemiology , Prevalence
13.
NMR Biomed ; 37(8): e5138, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38472163

ABSTRACT

Attention deficit hyperactivity disorder (ADHD) is a common mental health condition that significantly affects school-age children, causing difficulties with learning and daily functioning. Early identification is crucial, and reliable and objective diagnostic tools are necessary. However, current clinical evaluations of behavioral symptoms can be inconsistent and subjective. Functional magnetic resonance imaging (fMRI) is a non-invasive technique that has proven effective in detecting brain abnormalities in individuals with ADHD. Recent studies have shown promising outcomes in using resting state fMRI (rsfMRI)-based brain functional networks to diagnose various brain disorders, including ADHD. Several review papers have examined the detection of other diseases using fMRI data and machine learning or deep learning methods. However, no review paper has specifically addressed ADHD. Therefore, this study aims to contribute to the literature by reviewing the use of rsfMRI data and machine learning methods for detection of ADHD. The study provides general information about fMRI databases and detailed knowledge of the ADHD-200 database, which is commonly used for ADHD detection. It also emphasizes the importance of examining all stages of the process, including network and atlas selection, feature extraction, and feature selection, before the classification stage. The study compares the performance, advantages, and disadvantages of previous studies in detail. This comprehensive approach may be a useful starting point for new researchers in this area.


Subject(s)
Attention Deficit Disorder with Hyperactivity , Brain , Machine Learning , Magnetic Resonance Imaging , Attention Deficit Disorder with Hyperactivity/diagnostic imaging , Attention Deficit Disorder with Hyperactivity/physiopathology , Humans , Brain/diagnostic imaging , Brain/physiopathology , Rest
14.
Neuropsychol Rev ; 34(1): 320-337, 2024 Mar.
Article in English | MEDLINE | ID: mdl-36877328

ABSTRACT

Attention Deficit Hyperactivity Disorder (ADHD) is one of the most prevalent neurodevelopmental disorders in childhood and adolescence. Differences in reaction times (RT) in cognitive tasks have been consistently observed between ADHD and typical participants. Instead of estimating means and standard deviations, fitting non-symmetrical distributions like the ex-Gaussian, characterized by three parameters (µ, σ, and τ), account for the whole RT distributions. A meta-analysis is performed with all the available literature using ex-Gaussian distributions for comparisons between individuals with ADHD and controls. Results show that τ and σ are generally greater for ADHD samples, while µ tends to be larger for typical groups but only for younger ages. Differences in τ are also moderated by ADHD subtypes. τ and σ show, respectively, quadratic and linear relationships with inter-stimulus intervals from Continuous Performance Test and Go/No Go tasks. Furthermore, tasks and cognitive domains influence the three parameters. Interpretations of ex-Gaussian parameters and clinical implications of these findings are also discussed. Fitting ex-Gaussian distributions to RT data is a useful way to explore differences between individuals with ADHD and healthy controls.


Subject(s)
Attention Deficit Disorder with Hyperactivity , Neurodevelopmental Disorders , Adolescent , Humans , Reaction Time/physiology , Attention Deficit Disorder with Hyperactivity/psychology , Normal Distribution
15.
Toxicol Appl Pharmacol ; 486: 116946, 2024 May.
Article in English | MEDLINE | ID: mdl-38679241

ABSTRACT

The pathogenesis of attention-deficit/hyperactivity disorder (ADHD) has not been fully elucidated. Gestational hypertension could double the probability of ADHD in the offspring, while the initial bacterial communication between the mother and offspring has been associated with psychiatric disorders. Thus, we hypothesize that antihypertensive treatment during pregnancy may abate the impairments in neurodevelopment of the offspring. To test this hypothesis, we chose Captopril and Labetalol, to apply to pregnant spontaneously hypertensive rat (SHR) dams and examined the outcomes in the male offspring. Our data demonstrated that maternal treatment with Captopril and Labetalol had long-lasting changes in gut microbiota and behavioral alterations, including decreased hyperactivity and increased curiosity, spatial learning and memory in the male offspring. Increased diversity and composition were identified, and some ADHD related bacteria were found to have the same change in the gut microbiota of both the dam and offspring after the treatments. LC-MS/MS and immunohistochemistry assays suggested elevated expression of brain derived neurotrophic factor (BDNF) and dopamine in the prefrontal cortex and striatum of offspring exposed to Captopril/ Labetalol, which may account for the improvement of the offspring's psychiatric functions. Therefore, our results support the beneficial long-term effects of the intervention of gestational hypertension in the prevention of ADHD.


Subject(s)
Antihypertensive Agents , Attention Deficit Disorder with Hyperactivity , Behavior, Animal , Captopril , Gastrointestinal Microbiome , Prenatal Exposure Delayed Effects , Rats, Inbred SHR , Animals , Gastrointestinal Microbiome/drug effects , Pregnancy , Attention Deficit Disorder with Hyperactivity/drug therapy , Attention Deficit Disorder with Hyperactivity/chemically induced , Female , Antihypertensive Agents/pharmacology , Captopril/pharmacology , Male , Rats , Behavior, Animal/drug effects , Labetalol/pharmacology , Brain-Derived Neurotrophic Factor/metabolism , Hypertension, Pregnancy-Induced/chemically induced , Dopamine/metabolism
16.
Neuropsychol Rev ; 2024 Jun 22.
Article in English | MEDLINE | ID: mdl-38907905

ABSTRACT

Object recognition memory allows us to identify previously seen objects. This type of declarative memory is a primary process for learning. Despite its crucial role in everyday life, object recognition has received far less attention in ADHD research compared to verbal recognition memory. In addition to the existence of a small number of published studies, the results have been inconsistent, possibly due to the diversity of tasks used to assess recognition memory. In the present meta-analysis, we have collected studies from Web of Science, Scopus, PubMed, and Google Scholar databases up to May 2023. We have compiled studies that assessed visual object recognition memory with specific visual recognition tests (sample-match delayed tasks) in children and adolescents diagnosed with ADHD. A total of 28 studies with 1619 participants diagnosed with ADHD were included. The studies were assessed for risk of bias using the Quadas-2 tool and for each study, Cohen's d was calculated to estimate the magnitude of the difference in performance between groups. As a main result, we have found a worse recognition memory performance in ADHD participants when compared to their matched controls (overall Cohen's d ~ 0.492). We also observed greater heterogeneity in the magnitude of this deficit among medicated participants compared to non-medicated individuals, as well as a smaller deficit in studies with a higher proportion of female participants. The magnitude of the object recognition memory impairment in ADHD also seems to depend on the assessment method used.

17.
Neuropsychol Rev ; 2024 Jun 21.
Article in English | MEDLINE | ID: mdl-38902592

ABSTRACT

This meta-analytic study aims to investigate the cognitive correlates of risky decision-making in individuals with attention-deficit/hyperactivity disorder (ADHD) and typically developing (TD) individuals. A systematic analysis of existing literature was conducted, encompassing 38 studies (496 ADHD and 1493 TD). Findings revealed a consistent propensity for riskier decision-making in individuals with ADHD, supported by significant correlations with attention, cognitive flexibility, inhibitory control, time perception, and working memory. The study underscores the relevance of these cognitive functions in shaping decision-making tendencies, with nuanced patterns observed within the ADHD and TD subgroups. Individuals with ADHD often demonstrate altered patterns of correlation, reflecting the specific cognitive challenges characteristic of the disorder.

18.
Int J Neuropsychopharmacol ; 27(7)2024 Jul 01.
Article in English | MEDLINE | ID: mdl-38875132

ABSTRACT

BACKGROUND: A compelling hypothesis about attention-deficit/hyperactivity disorder (ADHD) etiopathogenesis is that the ADHD phenotype reflects a delay in cortical maturation. Slow-wave activity (SWA) of non-rapid eye movement (NREM) sleep electroencephalogram (EEG) is an electrophysiological index of sleep intensity reflecting cortical maturation. Available data on ADHD and SWA are conflicting, and developmental differences, or the effect of pharmacological treatment, are relatively unknown. METHODS: We examined, in samples (Mage = 16.4, SD = 1.2), of ever-medicated adolescents at risk for ADHD (n = 18; 72% boys), medication-naïve adolescents at risk for ADHD (n = 15, 67% boys), and adolescents not at risk for ADHD (n = 31, 61% boys) matched for chronological age and controlling for non-ADHD pharmacotherapy, whether ADHD pharmacotherapy modulates the association between NREM SWA and ADHD risk in home sleep. RESULTS: Findings indicated medication-naïve adolescents at risk for ADHD exhibited greater first sleep cycle and entire night NREM SWA than both ever-medicated adolescents at risk for ADHD and adolescents not at risk for ADHD and no difference between ever-medicated, at-risk adolescents, and not at-risk adolescents. CONCLUSIONS: Results support atypical cortical maturation in medication-naïve adolescents at risk for ADHD that appears to be normalized by ADHD pharmacotherapy in ever-medicated adolescents at risk for ADHD. Greater NREM SWA may reflect a compensatory mechanism in middle-later adolescents at risk for ADHD that normalizes an earlier occurring developmental delay.


Subject(s)
Attention Deficit Disorder with Hyperactivity , Electroencephalography , Humans , Attention Deficit Disorder with Hyperactivity/physiopathology , Attention Deficit Disorder with Hyperactivity/drug therapy , Adolescent , Male , Female , Sleep, Slow-Wave/physiology , Sleep, Slow-Wave/drug effects , Central Nervous System Stimulants/pharmacology , Sleep Stages/drug effects , Sleep Stages/physiology
19.
Br J Psychiatry ; 224(4): 127-131, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38362636

ABSTRACT

BACKGROUND: There are increasing calls for neurodivergent peoples' involvement in research into neurodevelopmental conditions. So far, however, this has tended to be achieved only through membership of external patient and public involvement (PPI) panels. The Regulating Emotions - Strengthening Adolescent Resilience (RE-STAR) programme is building a new participatory model of translational research that places young people with diagnoses of attention-deficit hyperactivity disorder (ADHD) and autism at the heart of the research team so that they can contribute to shaping and delivering its research plan. AIMS: To outline the principles on which the RE-STAR participatory model is based and describe its practical implementation and benefits, especially concerning the central role of members of the Youth Researcher Panel (Y-RPers). METHOD: The model presented is a culmination of a 24-month process during which Y-RPers moved from advisors to co-researchers integrated within RE-STAR. It is shaped by the principles of co-intentionality. The account here was agreed following multiple iterative cycles of collaborative discussion between academic researchers, Y-RPers and other stakeholders. RESULTS: Based on our collective reflections we offer general guidance on how to effectively integrate young people with diagnoses of ADHD and/or autism into the core of the translational research process. We also describe the specific theoretical, methodological and analytical benefits of Y-RPer involvement in RE-STAR. CONCLUSIONS: Although in its infancy, RE-STAR has demonstrated the model's potential to enrich translational science in a way that can change our understanding of the relationship between autism, ADHD and mental health. When appropriately adapted we believe the model can be applied to other types of neurodivergence and/or mental health conditions.


Subject(s)
Attention Deficit Disorder with Hyperactivity , Autism Spectrum Disorder , Autistic Disorder , Child Development Disorders, Pervasive , Child , Adolescent , Humans , Attention Deficit Disorder with Hyperactivity/diagnosis , Autism Spectrum Disorder/psychology , Translational Science, Biomedical
20.
Psychol Med ; 54(1): 148-158, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37185065

ABSTRACT

METHODS: Multiple Swedish nationwide registers were used to identify 8045 individuals, aged 20-29, with an incident diagnosis of ADHD 2006-2011. Labour market integration was conceptualized according to the core-peripheral model as a continuum from a strong (core) to a weak (peripheral) connection to the labour market. Sequence analyses categorized clusters of labour market integration, from 1 year before to 5 years after their ADHD diagnosis for individuals diagnosed with ADHD and a matched control group without ADHD. Multinomial logistic regression computed odds ratios (ORs) with 95% confidence intervals (CIs) between sociodemographic factors and comorbid disorders and the identified clusters. RESULTS: About one-fourth of the young adults diagnosed with ADHD belonged to clusters characterized by a transition to a mainly peripheral labour market position, which was approximately four-times higher compared to controls without ADHD. Foremost, those living in small cities/villages (OR 1.9; CI 1.5-2.2), those having comorbid autism-spectrum disorder (OR 13.7; CI 6.8-27.5) or schizophrenia/psychoses (OR 7.8; CI 3.8-15.9) were associated with a transition towards a peripheral labour market position throughout the study period. Those with a high educational level (OR 0.1; CI 0.1-0.1), and men (OR 0.7; CI 0.6-0.8) were less likely to have a peripheral labour market position. CONCLUSIONS: Young adults diagnosed with ADHD are four-times more likely to be in the peripheral labour market position compared to those without ADHD. To increase labour market participation, special attention is warranted to those with low educational level, those living outside big cities and those with comorbid mental disorders.


Subject(s)
Attention Deficit Disorder with Hyperactivity , Male , Humans , Young Adult , Attention Deficit Disorder with Hyperactivity/epidemiology , Attention Deficit Disorder with Hyperactivity/diagnosis , Sweden/epidemiology
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