•Excessive, spontaneous mind wandering is associated with attention deficit hyperactivity disorder (ADHD).•Deficient regulation of the default mode network in ADHD might lead to this type of mind ...wandering.•This neural dysregulation might also underpin inattention and deficient cognitive performance.•Converging evidence draws parallels between regulatory processes of mind wandering and deficient regulation in ADHD.
Attention-Deficit/Hyperactivity Disorder (ADHD) is a common neurodevelopmental disorder associated with a range of mental health, neurocognitive and functional problems. Although the diagnosis is based on descriptions of behaviour, individuals with ADHD characteristically describe excessive spontaneous mind wandering (MW). MW in individuals with ADHD reflects constant mental activity which lacks topic stability and content consistency. Based on this review of the neural correlates of ADHD and MW, we outline a new perspective on ADHD: the MW hypothesis. We propose that altered deactivation of the default mode network, and dysfunctional interaction with the executive control network, leads to excessive and spontaneous MW, which underpins symptoms and impairments of ADHD. We highlight that processes linked to the normal neural regulation of MW (context regulation, sensory decoupling, salience thresholds) are deficient in ADHD. MW-related measures could serve as markers of the disease process, as MW can be experimentally manipulated, as well as measured using rating scales, and experience sampling during both cognitive tasks and daily life. MW may therefore be a potential endophenotype.
•Exposure to metals/elements may be a risk factor for neurodevelopmental disorders.•We examined gestational levels of metals/elements and ADHD and autism in children.•Several metals and elements ...appeared to increase ADHD or autism risk.•Population levels of these chemicals may adversely affect neurodevelopment.
Prenatal exposure to toxic metals or variations in maternal levels of essential elements during pregnancy may be a risk factor for neurodevelopmental disorders such as attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) in offspring.
We investigated whether maternal levels of toxic metals and essential elements measured in mid-pregnancy, individually and as mixtures, were associated with childhood diagnosis of ADHD or ASD.
This study is based on the Norwegian Mother, Father and Child Cohort Study and included 705 ADHD cases, 397 ASD cases and 1034 controls. Cases were identified through linkage with the Norwegian Patient Registry. Maternal concentrations of 11 metals/elements were measured in blood at week 17 of gestation; cadmium; cesium; cobalt; copper; lead; magnesium; manganese; selenium; zinc; total arsenic; and total mercury. Multivariable adjusted logistic regression models were used to examine associations between quartile levels of individual metals/elements and outcomes. We also investigated non-linear associations using restricted cubic spline models. The joint effects of the metal/element mixture on ASD and ADHD diagnoses were estimated using a quantile-based g-computation approach.
For ASD, we identified positive associations (increased risks) in the second quartile of arsenic OR = 1.77 (CI: 1.26, 2.49) and the fourth quartiles of cadmium and manganese OR = 1.57 (CI: 1.07 2.31); OR = 1.84 (CI: 1.30, 2.59), respectively. In addition, there were negative associations between cesium, copper, mercury, and zinc and ASD. For ADHD, we found increased risk in the fourth quartiles of cadmium and magnesium OR = 1.59 (CI: 1.15, 2.18); OR = 1.42 (CI: 1.06, 1.91). There were also some negative associations, among others with mercury. In addition, we identified non-linear associations between ASD and arsenic, mercury, magnesium, and lead, and between ADHD and arsenic, copper, manganese, and mercury. There were no significant findings in the mixture approach analyses.
Results from the present study show several associations between levels of metals and elements during gestation and ASD and ADHD in children. The most notable ones involved arsenic, cadmium, copper, mercury, manganese, magnesium, and lead. Our results suggest that even population levels of these compounds may have negative impacts on neurodevelopment. As we observed mainly similarities among the metals’ and elements’ impact on ASD and ADHD, it could be that the two disorders share some neurochemical and neurodevelopmental pathways. The results warrant further investigation and replication, as well as studies of combined effects of metals/elements and mechanistic underpinnings.
Objective: Several studies suggest that parental ADHD impedes behavioral parent training (BPT) outcomes. Parental ADHD symptoms exhibited during BPT may interfere with the acquisition of new skills. ...This study explored the observed behavior of parents with ADHD during BPT. Method: Parents of children with ADHD attending group BPT completed self-ratings of their ADHD symptoms. Parents indicating a moderate level of ADHD symptoms were administered a clinical interview, and 37.3% of parents met ADHD criteria based on Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV) clinician-rated symptom counts. Results: Parents with high ADHD symptoms displayed more total and off-task violations compared with parents with low ADHD symptoms, although no significant differences emerged for other behaviors (i.e., working quietly, using materials appropriately, and remaining in seat), absences, or tardiness. Conclusion: Parental ADHD symptoms were manifested during BPT. Future research should clarify the nature of parental behavior in BPT as a possible mechanism explaining the relation between parental ADHD and impaired BPT outcomes.
Previous studies have reported a high prevalence of attention deficit hyperactivity disorder (ADHD) among people living in detention (PLD) corresponding to a five- to ten-fold increase compared to ...the general population. Our main study objective was to provide an updated ADHD prevalence rate for PLD, including PLD in psychiatric units. Sub-objectives included (i) comparing different ways of assessing ADHD, including DSM-5 criteria and (ii) identifying which types of PLD are more likely to have ADHD.
We conducted a systematic review and meta-analysis following the PRISMA guidelines and the MOOSE checklist. PubMed/Medline, PsycINFO, and Web of Sciences were searched combining "ADHD" and "prison" keywords and synonyms for articles published between January 1, 1966 and January 2, 2018. Potential sources of variation to the meta-analytic ADHD prevalence rate were investigated using meta-regressions and subgroups analyses.
The meta-analysis pooled 102 original studies including 69,997 participants. The adult ADHD prevalence rate was 26.2% (95% confidence interval: 22.7-29.6). Retrospective assessments of ADHD in childhood were associated with an increased prevalence estimate (41.1, 95% confidence interval: 34.9-47.2,
< 0.001). There was no significant difference in the prevalence estimate between screenings and clinical interviews in adulthood. Only three studies used the DSM-5 definition of ADHD and results were non-significantly different with other DSM versions. We found no difference according to participants' characteristics.
Our results confirmed the high prevalence rate of ADHD among PLD, corresponding to a five-fold increase compared to the general population. In light of such high ADHD prevalence, our results reinforce the importance of addressing this critical public health issue by (i) systematically offering ADHD screening and diagnosis to all individuals entering detention, and (ii) delivering treatment, monitoring, and care for ADHD during and after detention. These strategies may help reduce recidivism and reincarceration, as well as violence in detention settings, in addition to improving the health and wellbeing of people living in detention. Additionally, our study suggests that using screening scales may be a reliable way of assessing ADHD, although caution is needed because a complete evaluation by an experienced clinician is required to provide a formal diagnosis.
•Suspended children (with or without ADHD diagnoses) have higher delinquency scores than children who have never been suspended (with or without ADHD diagnoses).•School suspension and special ...education rates do not have a direct relationship with delinquency.•School special education enrollment rates are negative associated with delinquency for children who are neither suspended nor receive ADHD diagnoses (p <.10)•Suspended children (without ADHD diagnoses) in schools with high special education enrollment rates have higher delinquency rates than suspended children (without ADHD diagnoses) in schools with low special education enrollment rates.
In this paper, we examine the relationships between school suspensions and/or ADHD diagnoses and delinquency across different school disciplinary and special education climates. Given how these childhood interventions are intended to improve schoolchildren’s behavior and create a safe and predictable learning environment, it is critical for scholars to compare how these diverse yet connected responses to child misbehavior influence delinquent behavior. We use data from the Fragile Families and Child Well-Being Study (n = 2,267). Results from binomial regression models show that delinquency scores are higher among suspended children and children receiving both suspension and ADHD treatment, compared to young people who experience neither. Further, school context has a direct association with delinquency scores, as children attending schools with higher rates of school suspensions and special education enrollment have lower delinquency scores. Moreover, the relationship between individual childhood experiences with school suspension and/or ADHD treatment and delinquency is moderated by school context, especially regarding special education enrollment rates.
Psychiatric disorders are categorized on the basis of presence and absence of diagnostic criteria using classification systems such as the international classification of diseases (ICD) and the ...diagnostic and statistical manual for mental disorders (DSM). The research domain criteria (RDoC) initiative provides an alternative dimensional framework for conceptualizing mental disorders. In the present paper, we studied neural and behavioral effects of central stimulant (CS) medication in adults with attention deficit hyperactivity disorder (ADHD) and healthy controls using categorical and dimensional stratifications. AX-Continuous Performance Task (AX-CPT) was utilized for the later purpose, and participants were classified as “reactive” or “proactive” based on their baseline proactive behavioral index (PBI). Out of the 65 individuals who participated (33 healthy controls and 32 patients with ADHD), 53 were included in the final analysis that consisted of 31 healthy controls and 22 ADHD patients. For the dimensional stratification, a median split of PBI scores divided participants into “reactive” and “proactive” groups irrespective of whether they had ADHD or not. Participants performed AX-CPT in conjunction with functional magnetic resonance imaging (fMRI) before and after CS medication. We found no significant within or between group CS effect when participants were categorically assigned as healthy controls and ADHD patients. For the dimensional stratification, however, CS selectively increased activation in frontoparietal cognitive areas and induced a shift towards proactive control mode in the reactive group, without significantly affecting the proactive group. In conclusion, the neural and behavioral effects of CS were more clear-cut when participants were stratified into dimensional groups rather than diagnostic categories.
Objective
Longitudinal studies of children diagnosed with ADHD report widely ranging ADHD persistence rates in adulthood (5–75%). This study documents how information source (parent vs. self‐report), ...method (rating scale vs. interview), and symptom threshold (DSM vs. norm‐based) influence reported ADHD persistence rates in adulthood.
Method
Five hundred seventy‐nine children were diagnosed with DSM‐IV ADHD‐Combined Type at baseline (ages 7.0–9.9 years) 289 classmates served as a local normative comparison group (LNCG), 476 and 241 of whom respectively were evaluated in adulthood (Mean Age = 24.7). Parent and self‐reports of symptoms and impairment on rating scales and structured interviews were used to investigate ADHD persistence in adulthood.
Results
Persistence rates were higher when using parent rather than self‐reports, structured interviews rather than rating scales (for self‐report but not parent report), and a norm‐based (NB) threshold of 4 symptoms rather than DSM criteria. Receiver‐Operating Characteristics (ROC) analyses revealed that sensitivity and specificity were optimized by combining parent and self‐reports on a rating scale and applying a NB threshold.
Conclusion
The interview format optimizes young adult self‐reporting when parent reports are not available. However, the combination of parent and self‐reports from rating scales, using an ‘or’ rule and a NB threshold optimized the balance between sensitivity and specificity. With this definition, 60% of the ADHD group demonstrated symptom persistence and 41% met both symptom and impairment criteria in adulthood.
Read the Commentary on this article at doi: 10.1111/jcpp.12758
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Attention-deficit hyperactive disorder (ADHD) is characterized by inattention and increased impulsive and hypermotoric behaviors.Despite the high prevalence and impact of ADHD, little is known about ...the underlying neurophysiology of ADHD. The main inhibitory and excitatory neurotransmitters γ-aminobutyric acid (GABA) and glutamate are receiving increased attention in ADHD and can be measured using Magnetic Resonance Spectroscopy (MRS). However, MRS studies in ADHD are limited. We measured GABA and glutamate in young unmedicated participants, utilizing high magnetic field strength. Fifty unmedicated children (26 with ADHD, 24 controls) aged 5–9 years completed MRS at 7T and behavioral testing. GABA and glutamate were measured in dorsolateral prefrontal cortex (DLPFC), anterior cingulate cortex (ACC), premotor cortex (PMC), and striatum, and estimated using LCModel. Children with ADHD showed poorer inhibitory control and significantly reduced GABA/Cr in the striatum, but not in ACC, DLPFC, or PMC regions. There were no significant group differences for Glu/Cr levels, or correlations with behavioral manifestations of ADHD. The primary finding of this study is a reduction of striatal GABA levels in unmedicated children with ADHD at 7T. These findings provide guidance for future studies or interventions. Reduced striatal GABA may be a marker for specific GABA-related treatment for ADHD.
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