There is growing concern that phthalate exposures may have an impact on child neurodevelopment. Prenatal exposure to phthalates has been linked with externalizing behaviors and executive functioning ...defects suggestive of an attention-deficit hyperactivity disorder (ADHD) phenotype.
We undertook an investigation into whether prenatal exposure to phthalates was associated with clinically confirmed ADHD in a population-based nested case-control study of the Norwegian Mother and Child Cohort (MoBa) between the years 2003 and 2008.
Phthalate metabolites were measured in maternal urine collected at midpregnancy. Cases of ADHD (
=297) were obtained through linkage between MoBa and the Norwegian National Patient Registry. A random sample of controls (
=553) from the MoBa population was obtained.
In multivariable adjusted coexposure models, the sum of di-2-ethylhexyl phthalate metabolites (∑DEHP) was associated with a monotonically increasing risk of ADHD. Children of mothers in the highest quintile of ∑DEHP had almost three times the odds of an ADHD diagnosis as those in the lowest OR=2.99 (95% CI: 1.47, 5.49). When ∑DEHP was modeled as a log-linear (natural log) term, for each log-unit increase in exposure, the odds of ADHD increased by 47% OR=1.47 (95% CI: 1.09, 1.94). We detected no significant modification by sex or mediation by prenatal maternal thyroid function or by preterm delivery.
In this population-based case-control study of clinical ADHD, maternal urinary concentrations of DEHP were monotonically associated with increased risk of ADHD. Additional research is needed to evaluate potential mechanisms linking phthalates to ADHD. https://doi.org/10.1289/EHP2358.
Non-suicidal self-injury disorder (NSSID) is a new diagnosis proposed in DSM-5 with a need of further study, especially in adolescent clinical populations where non-suicidal self-injury (NSSI) is ...particularly prevalent. We aimed to study characteristics of NSSID and estimate an optimal cutoff frequency level of NSSI behavior.
Data were collected from 103 outpatient adolescents (ages 12-18) with recurrent self-harm behavior.
Adolescents with NSSID reported significantly more frequent NSSI behavior and suicide attempts than adolescents without NSSID. Frequency of NSSI, global functioning, depressive symptoms, number of self-harm methods and anxiety symptoms best discriminated between adolescents with and without NSSID. An optimal cutoff level for a diagnosis of NSSID was found to be ≥15 days with NSSI during the last year, which led to a reduction in the rate of adolescents diagnosed with NSSID from 54% to 46%.
This study shows that NSSID is a highly impairing disorder characterized by high risk of multiple NSSI and suicide attempts, decreased functioning and other associated psychiatric disorders. Clinical awareness of these risks are important to ensure early detection and treatment. Future prospective longitudinal studies are needed to further validate the characteristics of the NSSID diagnosis and its clinical utility.
Children with Disruptive Mood Dysregulation Disorder (DMDD) or Oppositional Defiant Disorder (ODD) are characterized by irritability and social difficulties. However, the mechanisms underlying these ...disorders could be different. This study explores differences in social cognition and executive function (EF) across DMDD and ODD and the influence of these factors and their interaction on social problems in both groups. Children with DMDD (n = 53, M
age
= 9.3) or ODD (n = 39, M
age
= 9.6) completed neuropsychological tasks measuring social cognition (Theory of Mind and Face-Emotion Recognition) and EF (cognitive flexibility, inhibition, and working memory). Parents reported social problems. More than one-third of the children with DMDD and almost two-thirds of those with ODD showed clear difficulties with Theory of Mind. Most children with DMDD (51-64%) or ODD (67-83%) showed difficulties with EF. In children with DMDD, worse EF (β = -.36) was associated with more social problems, whereas in children with ODD, better EF (β = .44) was associated with more social problems. In those with ODD, but not in those with DMDD, the interaction between social cognition and EF contributed to the explained variance of social problems (β = -1.97). Based on the observed interaction pattern, enhanced EF may lead to increased social problems among children with ODD who also exhibit social cognition difficulties. This study suggests the existence of distinct neuropsychological mechanisms underlying the social issues observed in children with DMDD versus those with ODD.
•We investigated the relations between phthalates and thyroid function mid-pregnancy.•We accounted for the urinary phthalate metabolite mixture by factor analyses.•We found relationships between ...phthalate factors and thyroid function, mainly T3.•Dietary iodine intake in pregnancy influenced some of these relationships.
Human populations, including susceptible subpopulations such as pregnant women and their fetuses, are continuously exposed to phthalates. Phthalates may affect the thyroid hormone system, causing concern for pregnancy health, birth outcomes and child development. Few studies have investigated the joint effect of phthalates on thyroid function in pregnant women, although they are present as a mixture with highly inter-correlated compounds. Additionally, no studies have investigated if the key nutrient for thyroid health, iodine, modifies these relationships.
In this study, we examined the cross-sectional relationships between concentrations of 12 urinary phthalate metabolites and 6 plasma thyroid function biomarkers measured mid-pregnancy (~17 week gestation) in pregnant women (N = 1072), that were selected from a population-based prospective birth cohort, The Norwegian Mother, Father and Child Cohort study (MoBa). We investigated if the phthalate metabolite-thyroid function biomarker associations differed by iodine status by using a validated estimate of habitual dietary iodine intake based on a food frequency questionnaire from the 22nd gestation week. We accounted for the phthalate metabolite mixture by factor analyses, ultimately reducing the exposure into two uncorrelated factors. These factors were used as predictors in multivariable adjusted linear regression models with thyroid function biomarkers as the outcomes.
Factor 1, which included high loadings for mono-iso-butyl phthalate (MiBP), mono-n-butyl phthalate (MnBP), and monobenzyl phthalate (MBzP), was associated with increased total triiodothyronine (TT3) and free T3 index (fT3i). These associations appeared to be driven primarily by women with low iodine intake (<150 µg/day, ~70% of our sample). Iodine intake significantly modified (p-interaction < 0.05) the association of factor 1 with thyroid stimulating hormone (TSH), total thyroxine (TT4) and free T4 index (fT4i), such that only among women in the high iodine intake category (≥150 µg/day, i.e. sufficient) was this factor associated with increased TSH and decreased TT4 and FT4i, respectively. In contrast, factor 2, which included high loadings for di-2-ethylhexyl phthalate metabolites (∑DEHP) and di-iso-nonyl phthalate metabolites (∑DiNP), was associated with a decrease in TT3 and fT3i, which appeared fairly uniform across iodine intake categories.
We find that phthalate exposure is associated with thyroid function in mid-pregnancy among Norwegian women, and that iodine intake, which is essential for thyroid health, could influence some of these relationships.
Objective: The aim of the study was to compare the development of working memory and preliminary stages of attentional processing in individuals with ADHD over a 23- to 25-year period. Method: ...Individuals with ADHD (n = 19) and healthy controls (n = 26) were followed up after 13 years (T2) and 23 to 25 years (T3) after initial assessment (T1). They were reassessed with diagnostic measures and the Backward masking task (pre-attention) and the Digit span distractibility test with and without distraction conditions (working memory). Results: The ADHD group performed below the healthy controls on all time points on the Digit span distractibility test. On the distractibility condition, we found a selective decline in performance from T2 to T3 for the ADHD group. Conclusion: The results highlight that ADHD individuals continue to display working memory deficits, also in adulthood, thus creating an imperative for cognitive rehabilitation techniques to help address attention difficulties.
Addressing current challenges in research on disruptive mood dysregulation disorder (DMDD), this study aims to compare executive function in children with DMDD, children with ...attention-deficit/hyperactivity disorder (ADHD), and children with oppositional defiant disorder (ODD). We also explore associations between irritability, a key DMDD characteristic, and executive function in a clinical sample regardless of diagnosis. Our sample include children (6–12 years) referred to child psychiatric clinics. Measures of daily-life (parent-reported questionnaire) and performance-based (neuropsychological tasks) executive function were applied. Identifying diagnoses, clinicians administered a standardized semi-structured diagnostic interview with parents. Irritability was assessed by parent-report. First, we compared executive function in DMDD (without ADHD/ODD), ADHD (without DMDD/ODD), ODD (without DMDD/ADHD) and DMDD + ADHD (without ODD). Second, we analyzed associations between executive function and irritability using the total sample. In daily life, children with DMDD showed clinically elevated and significantly worse emotion control scores compared to children with ADHD, and clinically elevated scores on cognitive flexibility compared to norm scores. Children with DMDD had significantly less working memory problems than those with ADHD. No differences were found between DMDD and ODD. Increased irritability was positively associated with emotional dyscontrol and cognitive inflexibility. For performance-based executive function, no diagnostic differences or associations with irritability were observed. We discuss how, in daily life, children with high irritability-levels get overwhelmed by feelings without accompanying regulatory capacities.
Background
Disruptive Mood Dysregulation Disorder was included in DSM-5 to accommodate new research addressing aspects of emotional dysregulation in children suffering from disruptive behavior ...problems. Despite growing interest in Disruptive Mood Dysregulation Disorder, few studies have looked at prevalence rates in European clinical populations. The primary objective of this study was to examine the prevalence and characteristics associated with Disruptive Mood Dysregulation Disorder in a Norwegian clinical sample.
Methods
The present study assessed children 6–12 years of age referred to a mental health clinic for evaluation and treatment (N = 218, M
age
= 9.6, 60.4% boys) and compared those who did and did not meet Disruptive Mood Dysregulation Disorder diagnostic criteria. Diagnoses were determined using K-SADS-PL 2013. Associated difficulties at home and in school were measured by Achenbach Systems of Empirically Based Assessment battery.
Results
In this clinical sample, 24% met the diagnostic criteria for Disruptive Mood Dysregulation Disorder. Children with Disruptive Mood Dysregulation Disorder were more likely than those without Disruptive Mood Dysregulation Disorder to be male (77% vs. 55%, p = .008), be living in poverty, have multiple mental health diagnoses (79% vs. 53%, p = .001), and have lower global functioning levels as measured by Children’s Global Assessment Scale (range 0–100, M = 47, SD = 8.5 vs. M = 57, SD = 11.4, p=<.001). Finally, parents and teachers of children with Disruptive Mood Dysregulation Disorder reported lower overall competence and adaptive functioning, and higher total symptom load than children with other diagnoses.
Conclusion
Disruptive Mood Dysregulation Disorder is highly prevalent in a Norwegian clinical sample and displays a high symptom load. Our results are in accordance with similar studies. Consistent findings across the world may support Disruptive Mood Dysregulation Disorder as a valid diagnostic category.
Objective: The objective of this article is to examine the associations between pre- and postnatal maternal distress and preschooler’s symptoms of ADHD, Oppositional Defiant Disorder (ODD), Conduct ...Disorder (CD), and anxiety, by timing and gender. Method: Children, aged 3.5 years (N = 1,195), recruited from the Norwegian Mother and Child Cohort Study, were assessed with a semistructured parental psychiatric interview. Perinatal maternal symptoms of distress were assessed by Symptom Checklist (SCL-5); Poisson regression was used to examine the associations. Results: Mid-gestational maternal distress significantly increased the average number of child symptoms, ranging between 3.8% for ADHD hyperactive–impulsive (ADHD-HI) and 8.7% for anxiety. The combination of high maternal scores of distress both pre- and postnatally were associated with increased risk of child symptoms of anxiety (relative risk RR = 2.10; 95% confidence interval CI = 1.43, 3.07), CD (RR = 1.83; 95% CI = 1.33, 2.51), and ODD (RR = 1.30; 95% CI = 1.03, 1.64), with minor sex differences. Conclusion: Maternal distress during mid-gestation was associated with ADHD, behavioral, and emotional symptoms in preschool children. Continued exposure into the postnatal period may further increase these risk associations .
To compare parent- and self-reported emotional and behavioral problems and quality of life (QoL) among youth with hearing loss (HL) to norms, and to investigate possible associations between ...emotional and behavioral problems and QoL among youth with HL.
We used the Strengths and Difficulties questionnaire (SDQ) and the Inventory of Life Quality in Children and Adolescents (ILC) to measure emotional and behavioral problems and QoL in youth with HL (n = 317, ages 6–18), where 78% had bilateral HL, 22% unilateral HL, 16% had cochlear implants, and 59% conventional hearing aids.
The youth with HL had significantly more parent-reported (but not self-reported) emotional and behavioral problems and poorer parent- and self-reported QoL than hearing youth. SDQ and ILC total scores were significantly correlated (−0.47 to −0.63). Conclusion Emotional and behavioral problems and poor QoL appear closely related in youth with HL, suggesting that attending to these problems may improve QoL.
•Youth with hearing loss have more emotional and behavioral problems than hearing.•Youth with hearing loss have poorer life quality than hearing youth.•Poorer life quality among youth with bilateral than unilateral hearing loss.•Emotional and behavioral problems and poor quality of life are interrelated.•Attend to emotional/behavioral problems to improve life quality when hearing loss.
Attention deficit hyperactivity disorder (ADHD) is a highly heritable neuropsychiatric condition, but it has been difficult to identify genes underlying this disorder. This study aimed to explore ...genetics of ADHD in an ethnically homogeneous Norwegian population by means of a genome-wide association (GWA) analysis followed by examination of candidate loci.
Participants were recruited through Norwegian medical and birth registries as well as the general population. Presence of ADHD was defined according to DSM-IV criteria. Genotyping was performed using Illumina Human OmniExpress-12v1 microarrays. Statistical analyses were divided into several steps: (1) genome-wide association in the form of logistic regression in PLINK and follow-up pathway analyses performed in DAPPLE and INRICH softwares, (2) SNP-heritability calculated using genome-wide complex trait analysis (GCTA) tool, (3) gene-based association tests carried out in JAG software, and (4) evaluation of previously reported genome-wide signals and candidate genes of ADHD.
In total, 1.358 individuals (478 cases and 880 controls) and 598.384 autosomal SNPs were subjected to GWA analysis. No single polymorphism reached genome-wide significance. The strongest signal was observed at rs9949006 in the ENSG00000263745 gene (OR=1.51, 95% CI 1.28-1.79, p=1.38E-06). Pathway analyses of the top SNPs implicated genes involved in the regulation of gene expression, cell adhesion and inflammation. Among previously identified ADHD candidate genes, prominent association signals were observed for SLC9A9 (rs1393072, OR=1.46, 95% CI = 1.21-1.77, p=9.95E-05) and TPH2 (rs17110690, OR = 1.38, 95% CI = 1.14-1.66, p=8.31E-04).
This study confirms the complexity and heterogeneity of ADHD etiology. Taken together with previous findings, our results point to a spectrum of biological mechanisms underlying the symptoms of ADHD, providing targets for further genetic exploration of this complex disorder.
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