A clinical study of attention-deficit/hyperactivity disorder in preschool children--prevalence and differential diagnoses

Psychiatric comorbidities of attention deficit/hyperactivity disorder in Japan: a nationwide population-based study

Introduction

This study aimed to estimate prevalence and incidence of attention deficit/hyperactivity disorder (ADHD) and comorbid relationships between ADHD and other psychiatric disorders in Japan.

Methods

Using the real-world JMDC Claims Database, we conducted a cross-sectional study (analysis years 2017-2021) and retrospective cohort study (observation 2 years before/after the initial ADHD diagnosis; data collection 2005-2021; enrollment 2017-2019). Patients were male or female, aged 0-57 years. Cross-sectional study patients had an ADHD or other psychiatric disorder diagnosis (with or without medication) and were continuously registered in each analysis year; retrospective study patients had an ADHD diagnosis and ≥2 years' observation before and after diagnosis. Endpoints were annual prevalence and incidence of ADHD in Japan, prevalence and risk ratio of each psychiatric comorbidity in patients with ADHD, prevalence and risk ratios of ADHD in patients with each psychiatric comorbidity, and prevalence of psychiatric disorders before/after the initial ADHD diagnosis.

Results

ADHD prevalence in children/adolescents and adults increased each year from 2017 to 2021. Prevalence in boys was 3.5-4.1 times higher than in girls. Prevalence in adults was lower than in children/adolescents, with a small sex difference. ADHD was highly comorbid with various psychiatric disorders. In 2019, the most common comorbidity in children/adolescents with ADHD was autism spectrum disorder (ASD; 54.4%); in adults, it was mood disorders (60.9%). ADHD prevalence in patients with various psychiatric disorders was higher than in the control population. ADHD prevalence was highest in patients with oppositional defiance disorder among both children/adolescents and adults (77.2% and 69.2%, respectively). In the retrospective cohort study (N = 14,940), the most common psychiatric disorders diagnosed prior to ADHD diagnosis were ASD in children/adolescents (33.9% of patients), and mood disorders and sleep disorders in adults (36.9% and 23.8% of patients, respectively).

Discussion

ADHD was comorbid with various psychiatric disorders in Japan. In children and adolescents with ADHD, ASD was often diagnosed prior to ADHD. Psychiatric disorders, especially mood disorders and sleep disorders, were frequently diagnosed prior to the initial ADHD diagnosis in adults. The likelihood of comorbid ADHD should be considered when diagnosing adult patients with psychiatric disorders.

Prevalence of attention-deficit hyperactivity disorder (ADHD): systematic review and meta-analysis

BACKGROUND

The estimates of attention-deficit hyperactivity disorder (ADHD) prevalence across various studies are significantly variable, contributing to uncertainty in ADHD prevalence estimation. Previous systematic reviews and meta-analyses have attributed this variability primarily to the methodological characteristics of the studies, including the diagnostic criteria, source of information, and impairment requirement for the diagnosis.

METHODS

Review identified studies reporting ADHD prevalence in representative samples of children and adults in Europe and worldwide. Studies that were conducted in the general population were included. We focused on studies that report ADHD prevalence based on clinical diagnosis (clinical diagnostic criteria based on the Diagnostic and Statistical Manual of Mental Disorders and International Classification of Diseases criteria, other diagnostic tools, such as various scales or interviews based on clinical diagnostic criteria). PubMed/Medline was searched to identify relevant articles published until 2024/2/01. The study was registered in PROSPERO (CRD42020200220) and followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines for systematic review and meta-analysis.

RESULTS

In total, 117 studies were subjected to full evaluation. In the meta-analysis, 103 studies representing 159 independent datapoints were included. The overall prevalence of ADHD in register studies was 1.6%, 95% CI [0.9; 3.0], in survey studies 5.0%, 95% CI [2.9; 8.6], in one-stage clinical studies 4.2%, 95% CI [2.9; 6.0], and in two-stage clinical studies 4.8%, 95% CI [4.0; 5.8].

CONCLUSIONS

Exact comparisons among studies with different diagnostic criteria and types of sampling can impact prevalence estimates. When comparing data from methodologically different studies, these factors need to be considered.

Predictors of probable attention deficit hyperactivity disorder in elderly patients with mild cognitive impairment visiting a memory clinic

Aim

Characteristics of attention deficit hyperactivity disorder (ADHD) that persist into old age are often confused with symptoms of mild cognitive impairment (MCI), and the actual rate of probable ADHD in people with MCI is unknown. This study estimated the proportion of MCI patients with probable ADHD and investigated the factors to identify MCI patients with probable ADHD.

Methods

We recruited 36 elderly patients (11 males, 25 females, mean age 72.4 ± 7.6 years) who met the MCI criteria. The MCI patients were classified as those with [MCI/ADHD (+)] and without [MCI/ADHD (-)] probable ADHD, according to the Wender Utah Rating Scale scores. The autism features, inattention, and hyperactivity features during childhood and current periods, estimated intelligence quotient, and demographic data were compared between the groups. Multiple logistic regression analysis was performed to identify factors of MCI/ADHD (+) patients.

Results

Nine (25.0%) and 27 patients were added into the MCI/ADHD (+) and MCI/ADHD (-) groups, respectively. The MCI/ADHD (+) group mostly comprised men, those who visited the clinic at a younger age, had more years of schooling, and had strong autism spectrum disorder tendencies. Multiple logistic regression analysis indicated male sex and current hyperactivity as significant predictors of probable ADHD in MCI patients.

Conclusion

A quarter of the patients with MCI had probable ADHD. Male sex and hyperactivity at the time of MCI diagnosis might help in predicting probable ADHD in MCI patients. However, these results were obtained from a single-center, small-case study and should be confirmed via longitudinal studies with a large number of cases.

Age of Diagnosis for Co-occurring Autism and Attention Deficit Hyperactivity Disorder During Childhood and Adolescence: a Systematic Review

Early identification and intervention are recognised as important elements of the clinical pathway for autism spectrum disorder (ASD). Children with ASD and attention deficit hyperactivity disorder (ADHD) may be diagnosed at a different age than children who only have one of these diagnoses. This systematic review aimed to identify the age at which children were diagnosed with both ASD and ADHD. Of the 9552 articles screened, 12 were included in the review. The findings suggest that ASD is typically diagnosed later when ADHD is present, and ADHD is typically diagnosed earlier when ASD is present. Further research is needed to understand the factors impacting a delayed ASD diagnosis and an earlier ADHD diagnosis when the two conditions co-occur.

Long-Term Treatment With Extended-Release Methylphenidate Treatment in Children Aged 4 to <6 Years

OBJECTIVE

To investigate long-term (12-month) safety and symptom control of extended-release methylphenidate (MPH-MLR) in children aged 4 to <6 years after treatment optimization.

METHOD

A total of 90 children aged 4 to <6 years with attention-deficit/hyperactivity disorder (ADHD) were enrolled from 2 MPH-MLR studies. Treatment-emergent adverse events (TEAEs) and ADHD symptom control were assessed in the safety population (n = 89) and modeled with mixed model analyses.

RESULTS

Most TEAEs (89.9%) were rated by investigators as of mild or moderate severity. One serious AE was reported (unrelated to study drug). Ten children discontinued because of TEAEs. Two discontinued because of weight loss; no significant increase in the rate of underweight children from baseline to endpoint was observed. Overall, 18% lost weight and 18% reported decreased appetite. Weight and height z scores and obesity rates decreased significantly from baseline to endpoint. Insomnia was reported (9%); none of these children discontinued. Sleep quality did not change significantly. Hypertension was reported (6.7%); none of these children dropped out. Diastolic, but not systolic, blood pressure increased significantly during the follow-up. Control of ADHD symptoms was maintained throughout follow-up.

CONCLUSION

These data contribute to the understanding of the long-term safety of an extended-release stimulant in children 4 to <6 years of age. The observed risk of a TEAE-related discontinuation was ∼11%. TEAEs were not dose related, and most were of mild to moderate severity. Symptom control was maintained through the year-long study.

CLINICAL TRIAL REGISTRATION INFORMATION

A 12-Month Open Label Safety Study of Aptensio XR® in Children Ages 4-5 Years Diagnosed With ADHD (EF004); https://clinicaltrials.gov; NCT02677519.

ADHD and Exposure to Maltreatment in Children and Youth: a Systematic Review of the Past 10 Years

PURPOSE OF THE REVIEW

The purpose of the current paper was to review and summarize the literature on ADHD and maltreatment over the past 10 years.

RECENT FINDINGS

The majority of research on ADHD and exposure to maltreatment focuses on the high rates of comorbidity, including international studies from Asia, South America, North America, and Europe. Longitudinal studies showed that early exposure to maltreatment is a risk factor for ADHD symptoms later in development; however, this finding was not consistent. There were some preliminary studies on the neurological and genetic mechanisms underlying the link between ADHD and exposure to maltreatment. Finally, ADHD and exposure to maltreatment were found to have an additive effect on clinically salient outcomes (e.g., aggression, suicide attempts). Results from the review have direct clinical and future implications, including the need to understand the effect of comorbid ADHD and exposure to maltreatment in treatment studies.

Randomized, Double-Blind, Placebo-Controlled, Flexible-Dose Titration Study of Methylphenidate Hydrochloride Extended-Release Capsules (Aptensio XR) in Preschool Children with Attention-Deficit/Hyperactivity Disorder

Objectives: To assess the efficacy and safety of a methylphenidate hydrochloride extended-release capsule (MPH-MLR) formulation in treating attention-deficit/hyperactivity disorder (ADHD) in preschool children. Methods: Children aged 4 to <6 years with qualifying ADHD Rating Scale Fourth Edition (ADHD-RS-IV) Preschool Version scores (≥90th percentile for age/gender) participated in four behavior management training (BMT) sessions or immediately entered (based on investigator assessment of symptom severity or previous participation) into a 6-week, open-label, flexible MPH-MLR dose optimization phase. After BMT, children with <30% improvement in ADHD-RS-IV score and ≥3 score on the Clinical Global Impression-Improvement (CGI-I) scale also entered the open-label period. All children began the open-label period with MPH-MLR 10 mg once daily; weekly adjustments permitted once-daily maximum of up to 40 mg. Children with ≥30% improvement in ADHD-RS-IV total score and a CGI-I score of 1-2 at open-label completion were randomized to their optimized dose of MPH-MLR or placebo for 2 weeks (double blind [DB]). Safety measures included adverse events (AEs), vital signs, and electrocardiograms. Results: Open-label enrollment was 119 children. Mean (SD) ADHD-RS-IV total scores at open-label start and open-label end was 40.8 (10.4) and 19.5 (11.1), respectively. Ninety children were enrolled in the DB phase. Mean (SD) ADHD-RS-IV total scores for the MPH-MLR and placebo group were similar at DB beginning and was 25.8 (14.6) and 34.9 (14.1), respectively, at DB end. Mean change from baseline in ADHD-RS-IV total score during DB was significantly greater in children randomized to placebo compared with MPH-MLR; least squares mean change difference from baseline was -11.2, p = 0.002. During open-label dosing, the most common AEs (≥10%) were decreased appetite, decreased weight, insomnia, hypertension, emotional disorder, and affect lability. Conclusion: Results demonstrate MPH-MLR efficacy in preschool children and a safety profile consistent with known AEs of methylphenidate when used for ADHD.

Behavior problems and dysfunctional parenting: Cross-sectional study in Japan

BACKGROUND

The Japanese government has established a law encouraging early detection and treatment of developmental disorders in children. Child behavior problems (CBP) tend to be recognized at school as a result of developmental disorders. The aim of this study was to identify factors associated with CBP in Japan. We hypothesized that factors other than developmental disorders are important in explaining CBP.

METHODS

The study was conducted between February and March 2015. Parents of 3,515 children aged 2-5 years attending one of 34 public nursery schools in Takamatsu, Kagawa, Japan received self-administered questionnaires addressing parental socioeconomic factors, mental health, parenting style (i.e. hostile, overreactive, or lax), developmental disorders in children, and CBP. A multiple regression analysis was applied to explore associations between CBP and possible factors.

RESULTS

Overall, 1,410 mothers were eligible to participate in the study. Children diagnosed with developmental disorders accounted for 7.8% of the sample, while on the Eyberg Child Behavior Inventory 17% of children had behavior problems needing clinical intervention. After adjustment for confounding factors, as well as for the diagnosis of developmental disorders, poor mental status and all three dysfunctional parenting styles had strong associations with CBP, and hostile, overreactive, and lax parenting had standardized β-values (β) of 0.29, 0.28, and 0.15, respectively (P < 0.01). A problematic relationship between the parents was also significantly associated with CBP (β = -0.29, P < 0.01).

CONCLUSION

When CBP are identified, parenting skills, mental health status and parental relationships should be considered along with the possibility of developmental disorders in the development of interventions.

Normative ADHD-RS-Preschool Data in a Community Sample in Spain

OBJECTIVE

The objective was to obtain normalized data from the ADHD Rating Scale-IV-Preschool Version (ADHD-RS-IV-P) in a Spanish sample.

METHOD

We translated and adapted the ADHD-RS-IV to our culture to obtain normalized data from a random representative sample of 1,426 Spanish preschool children (3 to <7 years old; 49.7% males). To analyze differences between evaluators, we used MANOVA. Internal consistency was assessed via Cronbach's alpha.

RESULTS

The mean age was 4.7 years old. There was a significant sex effect. The questionnaire had an internal consistency between .86 and .96 according to subscale and evaluator.

CONCLUSION

To evaluate ADHD in preschool children, it is necessary to use scores standardized by sex. Using a validated scale in schools and primary care centers may be useful for early detection of ADHD.

Prevalence of attention-deficit/hyperactivity disorder symptoms and their associations with sleep schedules and sleep-related problems among preschoolers in mainland China

Background

Attention-deficit/hyperactivity disorder (ADHD) among children is an increasing public health concern. The identification of behavioral risk factors, including sleep quality, has important public health implications for prioritizing behavioral intervention strategies for ADHD. Herein, this study aimed to investigate the prevalence of high levels of ADHD symptoms and to explore the association between sleep schedules, sleep-related problems and ADHD symptoms among preschoolers aged 3 to 6 years in mainland China.

Methods

A cross-sectional study was conducted, comprising a large sample of 15,291 preschoolers in Ma’anshan city of Anhui Province in China. ADHD symptoms were assessed by the 10-item Chinese version of the Conners Abbreviated Symptom Questionnaire (C-ASQ). Sleep-related variables included caregivers’ responses to specific questions addressing children’s daytime and nighttime sleep schedules, as well as sleep-related behaviors. Data on other factors were also collected, such as socio-demographic characteristics, TV viewing duration on weekdays and weekends, and outdoor activities. Logistic regression models were used to analyze the relationships between sleep schedules, sleep-related problems and ADHD symptoms.

Results

Approximately 8.6% of the total sample of preschoolers had high levels of ADHD symptoms, with boys having higher levels than girls (9.9% vs. 7.2%). In the logistic regression analysis, after adjusting for TV viewing duration, outdoor activities, and socio-demographic characteristics, delayed bedtime was significantly associated with a risk of high levels of ADHD symptoms, with odds ratios (OR) of 2.50 [95% confidence interval (CI): 2.09 ~ 3.00] and 2.04 (95% CI: 1.72 ~ 2.42) for weekdays and weekends, respectively. Longer time falling asleep (≥ 31 min) (OR = 1.76, 95% CI: 1.47 ~ 2.11), no naps (OR = 1.57, 95% CI: 1.34 ~ 1.84) and frequent sleep-related problems (OR = 4.57, 95% CI: 3.86 ~ 5.41) were also significantly associated with an increased risk of high levels of ADHD symptoms, while longer sleep duration (> 8.5 h) was associated with a decreased risk of high levels of ADHD symptoms (OR = 0.76, 95% CI: 0.67~ 0.87).

Conclusions

ADHD symptoms are prevalent in preschoolers in Ma’anshan region, China. Undesirable sleep schedules and sleep-related problems among preschoolers confer a risk of ADHD symptoms, highlighting the finding that beneficial and regular sleep habits potentially attenuate ADHD symptoms among preschoolers.

Neurological comorbidity in children with neurofibromatosis type 1

BACKGROUND

The aim of this study was to determine the frequency of central nervous system comorbidities in children with neurofibromatosis type 1 (NF1).

METHODS

We performed a nationwide survey to investigate neurological comorbidities in 3-15-year-old children with NF1 in Japan by sending questionnaires to pediatricians and pediatric neurologists. A secondary questionnaire was sent to the parents of identified NF1 patients to assess neurological comorbidities including headache, attention deficit-hyperactivity disorder (ADHD) Rating Scale (RS), and the Social Responsiveness Scale 2.

RESULTS

The primary survey identified 760 NF1 patients, and the parents of 565 patients were sent the secondary questionnaire. The parental response rate was 25.7% (145; 63 girls, 81 boys, one unspecified). Among the patients, 42.9% (55/128; 35 girls, 20 boys) were reported to exhibit intellectual problems. On the ADHD-RS, 40.2% (47/117) of NF1 patients aged 6-15 had ADHD (RS score >93rd percentile), with a rate of 47.7% in boys and 30.8% in girls. Furthermore, 20.2% of patients had suspected autism spectrum disorder (29/143; 10 girls, 19 boys), with Social Responsiveness Scale score ≥76. Headache was reported by 49.6% (61/123) of children over 5 years old, and 25.2% (31/123; 10 girls, 21 boys) reported migraine. Other neurological comorbidities included 20 cases of epilepsy (13.8%), 11 cases of optic nerve glioma (7.6%), five cases of brain tumor (3.4%), six cases of cerebrovascular disease (4.1%), and two cases of hydrocephalus (1.4%).

CONCLUSION

Intellectual problems, ADHD, autism spectrum disorder, and migraine are major neurological comorbidities in NF1.

Congenital cytomegalovirus in Japan: More than 2 year follow up of infected newborns

BACKGROUND

The aim of this study was to evaluate the outcome of congenital cytomegalovirus (CMV) infection identified on urine-filter screening assay at >2 years' follow up, and to observe the clinical outcomes after anti-CMV treatment.

METHODS

Sixty of 72 congenital CMV patients were enrolled and clinically observed for >2 years. Forty-three were asymptomatic at birth; seven were symptomatic at birth but untreated with anti-CMV drugs; and 10 were symptomatic and treated with anti-CMV drugs.

RESULTS

Of the 43 asymptomatic patients, three developed hearing loss or language disability for which association with congenital CMV has been repeatedly reported, and two had neurological sequelae of which the etiology was unclear, indicating that the rate of CMV-associated late-onset sequelae was 7-12%. All seven symptomatic infants without treatment developed sequelae, while three of the 10 treated patients were free from any sequelae.

CONCLUSIONS

The rate of late-onset sequelae observed in Japan is similar to that reported in the USA and Europe. The treatment of symptomatic patients with antiviral agents results in favorable clinical outcomes. Thus, newborn urine-filter paper screening of congenital CMV infection is warranted.

Klinische Diagnostik der ADHS im Vorschulalter

Die Aufmerksamkeitsdefizit-/Hyperaktivitätsstörung (ADHS) ist eine der häufigsten psychischen Störungen des Kindes- und Jugendalters und weist negative Folgen für die Betroffenen und das nähere Umfeld auf. Eine frühzeitige Erkennung von ADHS wäre für die Planung von Präventivmaßnahmen sinnvoll, um langfristige Folgen zu vermeiden. Ziel des Überblickartikels ist eine Bestandsaufnahme über die verfügbaren Fragebögen und klinischen Interviews zur Diagnostik von ADHS im Vorschulalter (3–5 Jahre). Es werden für den deutschen und den internationalen Raum verfügbare Verfahren verglichen und kritisch bewertet. Die Bedeutung von Fragebögen und klinischen Interviews im Rahmen einer ADHS-Diagnostik wird diskutiert.