Autism spectrum disorder (ASD) and Attention-deficit/hyperactivity disorder (ADHD) are often comorbid. The purpose of this study is to explore the relationships between ASD and ADHD symptoms by ...applying causal modeling. We used a large phenotypic data set of 417 children with ASD and/or ADHD, 562 affected and unaffected siblings, and 414 controls, to infer a structural equation model using a causal discovery algorithm. Three distinct pathways between ASD and ADHD were identified: (1) from impulsivity to difficulties with understanding social information, (2) from hyperactivity to stereotypic, repetitive behavior, (3) a pairwise pathway between inattention, difficulties with understanding social information, and verbal IQ. These findings may inform future studies on understanding the pathophysiological mechanisms behind the overlap between ASD and ADHD.
Attention deficit hyperactivity disorder (ADHD) is a highly heritable neuropsychiatric disorder. In the present study, the authors investigated the presence of genomic convergence in the top findings ...of the five published genome-wide association studies (GWASs) of ADHD.
The authors carried out bioinformatics pathway analyses, using the Ingenuity and BiNGO tools, as well as a systematic literature analysis of 85 genes from the five published GWASs containing single nucleotide polymorphisms associated with ADHD at a p value <0.0001.
Findings revealed that 45 of the 85 top-ranked ADHD candidate genes encode proteins that fit into a neurodevelopmental network involved in directed neurite outgrowth. Data on copy number variations in patients with ADHD and data from animal studies provide further support for the involvement of this network in ADHD etiology. Several network proteins are also directly modulated by stimulants, the most commonly used psychopharmacological treatment for ADHD.
The authors have identified a protein network for ADHD that contributes to our understanding of the molecular basis of the disorder. In addition, the data suggest new candidate genes for ADHD and provide clues to future research into psychopharmacological ADHD treatments.
We hypothesize that it is plausible that biologically distinct developmental ASD–ADHD subtypes are present, each characterized by a distinct time of onset of symptoms, progression and combination of ...symptoms. The aim of the present narrative review was to explore if structural brain imaging studies may shed light on key brain areas that are linked to both ASD and ADHD symptoms and undergo significant changes during development. These findings may possibly pinpoint to brain mechanisms underlying differential developmental ASD–ADHD subtypes. To this end we brought together the literature on ASD and ADHD structural brain imaging symptoms and particularly highlight the adolescent years and beyond. Findings indicate that the vast majority of existing MRI studies has been cross-sectional and conducted in children, and sometimes did include adolescents as well, but without explicitly documenting on this age group. MRI studies documenting on age effects in adults with ASD and/or ADHD are rare, and if age is taken into account, only linear effects are examined. Data from various studies suggest that a crucial distinctive feature underlying different developmental ASD–ADHD subtypes may be the differential developmental thinning patterns of the anterior cingulate cortex and related connections towards other prefrontal regions. These regions are crucial for the development of cognitive/effortful control and socio-emotional functioning, with impairments in these features as key to both ASD and ADHD.
Objective: The current longitudinal impact of treatment of ADHD on intimate partner violence (ITAP) study aims to investigate whether decrease of ADHD symptoms is associated with reduction of ...intimate partner violence (IPV) frequency in IPV offenders with ADHD in a forensic psychiatry setting. Method: Of n = 209 offenders of IPV with ADHD, frequency of IPV and ADHD symptoms were assessed at the 8th, 16th, 24th, and 52nd weeks of their combined treatment for ADHD and IPV. Results: We observed a significant decrease of self-reported ADHD symptoms (large effect size, d ≥ 0.80) and all IPV outcomes (small, d > 0.20, to large, d > 0.80, effect sizes). The decrease in IPV was mainly associated with the decrease in ADHD symptoms. Conclusion: As IPV treatment alone is not effective in the reduction of IPV in forensic psychiatry, we now have strong indications that the combined treatment of adult ADHD and IPV is more effective in offenders with ADHD.
Methylphenidate (MPH), the most common medication for children with Attention Deficit/Hyperactivity Disorder (ADHD) in many countries, is often prescribed for long periods of time. Any long-term ...psychotropic treatment in childhood raises concerns about possible adverse neurological and psychiatric outcomes.
We aimed to map current evidence regarding neurological and psychiatric outcomes, adverse or beneficial, of long-term MPH (> 1 year) treatment in ADHD. We coded studies using a “traffic light” system: Green: safe/favours MPH; Amber: warrants caution; Red: not safe/not well-tolerated. Un-categorisable study findings were coded as “Unclear”.
Although some evidence suggests an elevated risk of psychosis and tics, case reports describe remission on discontinuation. Several studies suggest that long-term MPH may reduce depression and suicide in ADHD. Evidence suggests caution in specific groups including pre-school children, those with tics, and adolescents at risk for substance misuse.
We identified a need for more studies that make use of large longitudinal databases, focus on specific neuropsychiatric outcomes, and compare outcomes from long-term MPH treatment with outcomes following shorter or no pharmacological intervention.
•Pregnancy smoking and alcohol use are associated with offspring conduct problems.•Findings also suggest a stronger effect in clinical samples.•We report no clear effects of cannabis and caffeine, ...but studies were few.•Causality issues due to shared genetic and social factors need to be addressed.
We conducted meta-analyses of relationships between highly prevalent substance use during pregnancy and offspring conduct disorder problems. In total 36 studies were included. Odds ratios (ORs) were 2.06 (1.67–2.54, 25 studies) for maternal smoking, 2.11 (1.42–3.15, 9 studies) for alcohol use, and 1.29 (0.93–1.81, 3 studies) for cannabis use, while a single study of caffeine use reported no effects. Our meta-analyses support an association between smoking and alcohol use during pregnancy, and offspring conduct problems, yet do not resolve causality issues given potential confounding by genetic factors, gene-environment interactions, and comorbidity such as with attention deficit hyperactivity disorders. Future studies should use genetically sensitive designs to investigate the role of pregnancy substance use in offspring conduct problems and may consider more broadly defined behavioral problems.
Pivotal Response Treatment (PRT) is a promising intervention addressing core symptoms of autism spectrum disorder (ASD), with parent involvement as key component. Parent group-delivered PRT may be an ...effective treatment model, but currently the evidence is limited. Also, little attention has been paid to therapeutic involvement of multiple important contexts (e.g. home, school, community) of the young child. The current study explores a 14-week protocol of PRT parent group training (PRT-PG), complemented with individual parent-child sessions and involvement of teachers and other childcare providers. Children aged 2-6 years old with ASD and their parents (n = 20) were included. Preliminary results showed a significant increase in spontaneous initiations during a semi-structured therapist-child interaction together with widespread gains in clinical global functioning. No significant improvement on parent-rated general social-communication skills was observed. These findings justify further research on parent group delivered PRT models.
Impaired response inhibition is commonly present in individuals with attention-deficit/hyperactivity disorder (ADHD) and their unaffected relatives, suggesting impaired response inhibition as a ...candidate endophenotype in ADHD. Therefore, we explored whether behavioral and neural correlates of response inhibition are related to polygenic risk scores for ADHD (PRS-ADHD). We obtained functional magnetic resonance imaging of neural activity and behavioral measures during a stop-signal task in the NeuroIMAGE cohort, where inattention and hyperactivity-impulsivity symptoms were assessed with the Conners Parent Rating Scales. Our sample consisted of 178 ADHD cases, 103 unaffected siblings, and 173 controls (total
N
= 454; 8–29 years), for whom genome-wide genotyping was available. PRS-ADHD was constructed using the PRSice-2 software. We found PRS-ADHD to be associated with ADHD symptom severity, a slower and more variable response to Go-stimuli, and altered brain activation during response inhibition in several regions of the bilateral fronto-striatal network. Mean reaction time and intra-individual reaction time variability mediated the association of PRS-ADHD with ADHD symptoms (total, inattention, hyperactivity-impulsivity), and activity in the left temporal pole and anterior parahippocampal gyrus during failed inhibition mediated the relationship of PRS-ADHD with hyperactivity-impulsivity. Our findings indicate that PRS-ADHD are related to ADHD severity on a spectrum of clinical, sub-threshold, and normal levels; more importantly, we show a shared genetic etiology of ADHD and behavioral and neural correlates of response inhibition. Given the modest sample size of our study, future studies with higher power are warranted to explore mediation effects, suggesting that genetic liability to ADHD may adversely affect attention regulation on the behavioral level and point to a possible response inhibition-related mechanistic pathway from PRS-ADHD to hyperactivity-impulsivity.
Attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) are both highly heritable neurodevelopmental disorders. Evidence indicates both disorders co-occur with a high ...frequency, in 20–50% of children with ADHD meeting criteria for ASD and in 30-80% of ASD children meeting criteria for ADHD. This review will provide an overview on all available studies family based, twin, candidate gene, linkage, and genome wide association (GWA) studies shedding light on the role of shared genetic underpinnings of ADHD and ASD. It is concluded that family and twin studies do provide support for the hypothesis that ADHD and ASD originate from partly similar familial/genetic factors. Only a few candidate gene studies, linkage studies and GWA studies have specifically addressed this co-occurrence, pinpointing to some promising pleiotropic genes, loci and single nucleotide polymorphisms (SNPs), but the research field is in urgent need for better designed and powered studies to tackle this complex issue. We propose that future studies examining shared familial etiological factors for ADHD and ASD use a family-based design in which the same phenotypic (ADHD and ASD), candidate endophenotypic, and environmental measurements are obtained from all family members. Multivariate multi-level models are probably best suited for the statistical analysis.
PDF
