Male and Female Toddlers with DSM-5 Autism Spectrum Disorder have Similar Developmental Profiles and Core Autism Symptoms

Compare developmental profiles and core ASD symptom manifestation between male and female toddlers with DSM-5 ASD. Retrospective record review of 500 toddlers (79% male) at time of ASD diagnosis. There were no differences in developmental functioning between males and females. When adjusting for multiple comparisons, sex differences were only noted for sensory seeking behavior occurring at a higher frequency in females. Overall, there were no significant differences in demographic characteristics, developmental functioning, or manifestation of core ASD symptoms between males versus female toddlers at the time of DSM-5 ASD diagnosis.

Development and implementation of a longitudinal clinical database for down syndrome in a large pediatric specialty clinic: Methodology and feasibility

Down syndrome (DS) is a complex condition associated with multiple medical, developmental, and behavioral concerns. A prospective, longitudinal clinical database was integrated into a specialty Down Syndrome Program, with the goals of better understanding the incidence, course, and impact of co-occurring medical, neurodevelopmental, and mental health conditions in DS. We describe the process of developing the database, including a systematic approach to data collection and database infrastructure, and report on feasibility, challenges, and solutions of initial implementation. Between March 2018 and November 2021, data from 842 patients (ages 4.8 months to 26 years) was collected. Challenges included caregiver form completion as well as time and personnel required for successful implementation. With full integration into clinical visit flow, the database proved to be feasible. The database enables identification of patterns of development and health throughout the lifespan and it facilitates future data sharing and collaborative research to advance care.

Co-occurring conditions in Down syndrome: Findings from a clinical database

Individuals with Down syndrome (DS) experience a range of medical and neurodevelopmental conditions, necessitating systematic study of their occurrence and impact on neurodevelopmental outcomes. We describe the prevalence and relationships of medical, neurodevelopmental (ND), and mental health (MH) conditions in children with DS. We created a prospective clinical database of individuals with DS, integrated into the workflow of a specialty Down Syndrome Program at a specialty pediatric referral hospital. Conditions were collected through caregiver- and clinician report at clinical visits (N = 599). We calculated frequencies of medical, ND, and MH conditions and then assessed the relationship between medical, ND, and MH conditions using frequencies and comparative statistics. The most frequent co-occurring conditions were vision (72.5%), ear/hearing (71.0%), gastrointestinal (61.3%), respiratory (45.6%), and feeding (33.6%) problems, with variation in frequency by age. ND and MH conditions were reported in one quarter, most commonly autism spectrum disorder and attention-deficit/hyperactivity disorder. Those with ND and MH conditions had greater frequency of medical conditions, with highest rates of vision, ear/hearing, and gastrointestinal issues, and CHD. Systematically collected clinical data in a large cohort of children with DS reveals high prevalence of several co-occurring medical, ND, and MH conditions. Clinical care requires an understanding of the complex relationship between medical conditions and neurodevelopment.

Persistence of Autism Spectrum Disorder From Early Childhood Through School Age

Importance

While the prevalence of autism spectrum disorder (ASD) continues to increase and early diagnosis is emphasized, there is limited information on outcomes for children diagnosed with ASD in early childhood using contemporary diagnostic criteria.

Objectives

To determine the frequency with which children who are clinically diagnosed with ASD at 12 to 36 months of age continue to meet diagnostic criteria for ASD at 5 to 7 years of age and to evaluate whether baseline child-specific and demographic characteristics and receipt of interventions are associated with ASD persistence.

Design, Setting, and Participants

In this natural history cohort study, children who received a clinical ASD diagnosis at 12 to 36 months of age underwent a research diagnostic assessment at 5 to 7 years of age. Research assessments occurred from August 14, 2018, to January 8, 2022.

Intervention

Children received community-based interventions, and parents provided details about interventions received.

Main Outcomes and Measures

The main outcome was persistence of ASD diagnosis based on current functioning. An experienced research psychologist assigned an ASD diagnosis (present or absent) according to criteria from the Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition) after the research assessment. The research assessment included administration of the Autism Diagnostic Observation Schedule-2, Autism Diagnostic Interview-Research, and a cognitive measure.

Results

Of the 213 participants diagnosed with ASD at initial clinical assessment (mean [SD] age, 24.6 [3.9] months; 177 boys [83.1%]), 79 (37.1%) did not continue to meet diagnostic criteria for ASD (nonpersistent ASD) at research assessment (mean [SD] age, 74.3 [7.1] months). All children with nonpersistent ASD had IQ of at least 70, while there was a bimodal distribution of IQ for those with persistent ASD (46 with IQ <70 and 88 with IQ ≥70). All children received some interventions, and 201 (94.4%) received ASD-specific intervention, mostly applied behavioral analysis. In a multilevel logistic regression model, the only variables associated with increased odds of being in the nonpersistent ASD group at 6 years of age were higher baseline adaptive skills (b coefficient = -0.287 [SE, 0.108]) and female sex (b = 0.239 [SE, 0.064]).

Conclusions and Relevance

The findings of this cohort study suggest that among toddlers diagnosed with ASD, baseline adaptive function and sex may be associated with persistence of ASD.

Children With ADHD Are at Risk for a Broad Array of Adverse Adult Outcomes That Cross Functional Domains: Results From a Population-Based Birth Cohort Study

OBJECTIVE

To identify patterns ("classes") of outcomes for adults with and without childhood ADHD.

METHOD

Subjects were 232 childhood ADHD cases and 335 non-ADHD referents from a 1976 to 1982 birth cohort. We used latent class analyses to identify classes based on a broad array of adult psychosocial outcomes and determined the proportion of subjects with childhood ADHD within each class.

RESULTS

A three class solution provided optimal model fit; classes were termed "good," "intermediate," and "poor" functioning. Subjects with childhood ADHD comprised 62.8% of the "poor," 53.5% of the "intermediate," and 24.9% of the "good" functioning class. The "poor" functioning class was distinguished by increased likelihood of legal trouble and substance use disorders and included more individuals with childhood ADHD and psychiatric disorder than the "intermediate" class (45.5% vs. 30.6%).

CONCLUSION

Children with ADHD are at risk for adverse adult outcomes in multiple domains and co-morbid childhood psychiatric disorders increase risk.

Recalled Experiences of Bullying and Victimization in a Longitudinal, Population-Based Birth Cohort: The Influence of ADHD and Co-Occurring Psychiatric Disorder

OBJECTIVE

To describe bullying experiences throughout childhood of people with and without childhood ADHD and co-occurring learning and psychiatric disorders from a population-based birth cohort.

METHODS

In a secondary data analysis of 199 childhood ADHD cases and 287 non-ADHD referents (N = 486), reported experiences of peer interactions during elementary, middle, or high school were classified as "bully," "victim," "neither," or "both." Associations were assessed with multinomial logistic regression.

RESULTS

Adjusted for male sex, the odds of classification as victim-only, victim/bully, or bully- only (vs. neither) were 3.70 (2.36-5.81), 17.71, and 8.17 times higher for childhood ADHD cases compared to non-ADHD referents. Victim-bullies (62.5%) and bullies (64.3%) had both childhood ADHD and other psychiatric disorders versus 38.4% of victims-only and 17.3% of those classified as "neither."

CONCLUSION

The list of serious lifetime consequences of having ADHD also includes bullying. We offer future research directions for determining potential causal pathways.

Identifying Subgroups of Toddlers with DSM-5 Autism Spectrum Disorder Based on Core Symptoms

The objective of this study was to identify subgroups of toddlers with DSM-5 ASD based on core ASD symptoms using a person-based analytical framework. This is a retrospective study of 500 toddlers (mean age 26 months, 79% male) with DSM-5 ASD. Data were analyzed using latent class analyses in which profiles were formed based on ASD symptomatology. Social communication (SC) symptoms favored a three-class solution, while restricted/repetitive behaviors (RRBs) favored a two-class solution. Classes with higher consistency of SC deficits were younger, with lower developmental functioning. The class with more RRBs was older, with higher functioning. If confirmed in other populations, these classes may more precisely characterize subgroups within the heterogeneous group of toddlers at time of ASD diagnosis.

Pathogenic Yield of Genetic Testing in Autism Spectrum Disorder

BACKGROUND AND OBJECTIVES

Genetic testing is recommended for individuals with autism spectrum disorder (ASD). Pathogenic yield varies by clinician and/or patient characteristics. Our objectives were to determine the pathogenic yield of genetic testing, the variability in rate of pathogenic results based on subject characteristics, and the percentage of pathogenic findings resulting in further medical recommendations in toddlers with a Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition diagnosis of ASD.

METHODS

We conducted a retrospective chart review of 500 toddlers, 18 to 36 months, diagnosed with Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition ASD (mean age: 25.8 months, 79% male). Subject demographics, medical and neuropsychological characteristics, and genetic test results were abstracted. Genetic results were divided into negative or normal, variants of unknown significance, and pathogenic. Subject characteristics were compared across results. Manual chart review determined if further recommendations were made after pathogenic results.

RESULTS

Over half of subjects (59.8%, n = 299) completed genetic testing, and of those, 36 (12.0%) had pathogenic findings. There were no significant differences in Bayley Scales of Infant Development cognitive (P = .112), language (P = .898), or motor scores (P = .488) among children with negative or normal findings versus a variant of unknown significance versus pathogenic findings. Medical recommendations in response to the genetic finding were made for 72.2% of those with pathogenic results.

CONCLUSIONS

Our findings reinforce the importance of genetic testing for toddlers diagnosed with ASD given the 12% yield and lack of phenotypic differences between subjects with and without pathogenic findings. The majority of pathogenic results lead to further medical recommendations.

Psychiatric Comorbidities Modify the Association Between Childhood ADHD and Risk for Suicidality: A Population-Based Longitudinal Study

OBJECTIVE

The objective of this study was to evaluate the effect of psychiatric comorbidities on the association between childhood ADHD and suicidality among adults.

METHOD

Subjects were recruited from a population-based birth cohort. Participating adult subjects with childhood ADHD and non-ADHD controls were administered a structured psychiatric interview to assess suicidality and psychiatric comorbidities. Associations were assessed using logistic regression.

RESULTS

Compared with controls, ADHD cases were significantly more likely to meet criteria for suicidality. Subjects with childhood ADHD who met criteria for generalized anxiety disorder had a higher than expected risk of suicidality with an observed odds ratio of 10.94 (95% confidence interval [4.97, 24.08]) compared with an expected odds ratio of 4.86, consistent with a synergistic interaction effect. Significant synergistic interactions were also observed for hypomanic episode and substance-related disorders.

CONCLUSION

Childhood ADHD is significantly associated with adult suicidal risk. Comorbidity between ADHD and some psychiatric disorders is associated with a higher suicidal risk than expected.

Using ADHD Medications to Treat Coexisting ADHD and Reading Disorders: A Systematic Review

Attention-deficit/hyperactivity disorder (ADHD), the most common pediatric neurobehavioral disorder, frequently presents with coexisting reading disorders (RDs). Despite this, it is unclear whether medication improves symptoms and function in children with comorbid ADHD and RD. We present a systematic review of studies investigating the effects of ADHD medications on ADHD symptoms, academic outcomes, and neuropsychological measures in this important group.

Adults With Persistent ADHD: Gender and Psychiatric Comorbidities-A Population-Based Longitudinal Study

OBJECTIVE

The aim of the study was to evaluate associations between ADHD and comorbid psychiatric disorders among adults from a population-based birth cohort.

METHOD

Participants were recruited from all children born between 1976 and 1982 remaining in Rochester, Minnesota, after age 5. Participants with childhood ADHD ( n = 232; M age = 27.0 years; 72% men) and non-ADHD controls ( n = 335; M age = 28.6 years; 63% men) completed a structured interview (M.I.N.I. International Neuropsychiatric Interview) assessing current ADHD status and comorbid psychiatric disorders.

RESULTS

Among 232 with childhood ADHD, 68 (49 men, 19 women) had persistent adult ADHD. Compared with non-ADHD controls and non-persistent ADHD participants, adults with persistent ADHD were significantly more likely to have any or each of 12 psychiatric comorbidities. The associations retained significant or marginally significant when stratified by gender. Externalizing psychiatric disorders were more common in men (74%) and internalizing disorders in women (58%).

CONCLUSION

Persistent ADHD is associated with an increased risk of comorbid psychiatric disorders in adult men and women.

Comparing Methods to Determine Persistence of Childhood ADHD Into Adulthood: A Prospective, Population-Based Study

OBJECTIVE

To compare the rate of persistence of ADHD into adulthood as determined by a norm-referenced versus non-norm-referenced diagnostic interview, and by standardized questionnaires.

METHOD

Adults from a birth cohort, including research-identified childhood ADHD cases ( N = 232; M_age = 27.0 years; 167 males, 65 females) and controls ( N = 335; M_age = 28.6 years; 210 males, 125 females), were administered the M.I.N.I. International Neuropsychiatric Interview, the Murphy-Barkley Symptoms Checklist (MB), and the Wender Utah Rating Scale (WURS) Results: Among the childhood ADHD cases, 29.3% fulfilled criteria for adult ADHD using a norm-referenced approach to M.I.N.I. scoring, versus 13.8% using published M.I.N.I. criteria. Among participants meeting norm-referenced diagnostic criteria, 41.8% and 69.1% were classified as adult ADHD using the MB and WURS, respectively.

CONCLUSION

A non-norm-referenced approach resulted in a significant underestimate of the rate of adult ADHD. Reliance on either of two adult ADHD questionnaires would have further reduced this estimate.

Mediating and Moderating Role of Depression, Conduct Disorder or Attention-Deficit/Hyperactivity Disorder in Developing Adolescent Substance Use Disorders: A Population-Based Study

Objective

To evaluate the mediating/moderating effects of common internalizing /externalizing disorders on the association between ADHD and adolescent substance use disorders (SUD) in a population-based birth cohort.

Methods

Among 5718 children in the birth cohort, 343 ADHD incident cases and 712 matched controls were identified. Psychiatric diagnoses prior to age 19 were classified into DSM-IV categories. The association between ADHD and SUD was summarized (hazard ratios (HR), 95% CI). The effect of depression, CD/ODD, anxiety was evaluated separately.

Results

Assessment of the joint effects of ADHD and each psychiatric disorder did not support a moderating effect of these disorders on SUD on additive scale. However, the association between ADHD and SUD was partially explained by a mediating role of these psychiatric disorders.

Conclusion

For clinicians our results emphasize that depression (or CD/ODD) confers greater risk for SUD than ADHD alone. Early detection/treatment of SUD among adolescents with depression (or CD/ODD) is crucial regardless of ADHD.

Childhood Attention-Deficit/Hyperactivity Disorder, Sex, and Obesity: A Longitudinal Population-Based Study

OBJECTIVE

To assess obesity rates during childhood and young adulthood in patients with attention-deficit/hyperactivity disorder (ADHD) and age- and sex-matched controls derived from a population-based birth cohort because cross-sectional studies suggest an association between ADHD and obesity.

PATIENTS AND METHODS

Study subjects included patients with childhood ADHD (n=336) and age- and sex-matched non-ADHD controls (n=665) from a 1976 to 1982 birth cohort (N=5718). Height, weight, and stimulant treatment measurements were abstracted retrospectively from medical records documenting care provided from January 1, 1976, through August 31, 2010. The association between ADHD and obesity in patients with ADHD relative to controls was estimated using Cox models.

RESULTS

Patients with attention-deficit/hyperactivity disorder were 1.23 (95% CI, 1.00-1.50; P<.05) times more likely to be obese during the follow-up period than were non-ADHD controls. This association was not statistically significant in either sex (female participants: hazard ratio [HR], 1.49; 95% CI, 0.98-2.27; P=.06; male participants HR, 1.17, 95% CI, 0.92-1.48; P=.20). Patients with ADHD who were not obese as of the date ADHD research diagnostic criteria were met were 1.56 (95% CI, 1.14-2.13; P<.01) times more likely to be obese during the subsequent follow-up than were controls. This association was statistically significant in female study subjects (HR, 2.02; 95% CI, 1.13-3.60; P=.02), but not in male participants (HR, 1.41; 95% CI, 0.97-2.05; P=.07). A higher proportion of patients with ADHD were obese after the age of 20 years compared with non-ADHD controls (34.4% vs 25.1%; P=.01); this difference was observed only in female patients (41.6% vs 19.2%). There were no differences in obesity rates between stimulant-treated and nontreated patients with ADHD.

CONCLUSION

Childhood ADHD is associated with obesity during childhood and young adulthood in females. Treatment with stimulant medications is not associated with the development of obesity up to young adulthood.

Comparing Diagnostic Outcomes of Autism Spectrum Disorder Using DSM-IV-TR and DSM-5 Criteria

Controversy exists regarding the DSM-5 criteria for ASD. This study tested the psychometric properties of the DSM-5 model and determined how well it performed across different gender, IQ, and DSM-IV-TR sub-type, using clinically collected data on 227 subjects (median age = 3.95 years, majority had IQ > 70). DSM-5 was psychometrically superior to the DSM-IV-TR model (Comparative Fit Index of 0.970 vs 0.879, respectively). Measurement invariance revealed good model fit across gender and IQ. Younger children tended to meet fewer diagnostic criteria. Those with autistic disorder were more likely to meet social communication and repetitive behaviors criteria (p < .001) than those with PDD-NOS. DSM-5 is a robust model but will identify a different, albeit overlapping population of individuals compared to DSM-IV-TR.

ADHD, stimulant treatment, and growth: a longitudinal study

BACKGROUND AND OBJECTIVE

There is ongoing concern that stimulant medications may adversely affect growth. In a sample of attention-deficit/hyperactivity disorder (ADHD) cases and controls from a population-based birth cohort, we assessed growth and the association between stimulant treatment and growth.

METHODS

Subjects included childhood ADHD cases (N = 340) and controls (N = 680) from a 1976 to 1982 birth cohort (N = 5718). Height and stimulant treatment information were abstracted from medical records and obtained during a prospective, adult follow-up study. For each subject, a parametric penalized spline smoothing method modeled height over time, and the corresponding height velocity was calculated as the first derivative. Peak height velocity (PHV) age and magnitude were estimated from the velocity curves. Among stimulant-treated ADHD cases, we analyzed height Z scores at the beginning, at the end, and 24 months after the end of treatment.

RESULTS

Neither ADHD itself nor treatment with stimulants was associated with differences in magnitude of PHV or final adult height. Among boys treated with stimulants, there was a positive correlation between duration of stimulant usage before PHV and age at PHV (r = 0.21, P = .01). There was no significant correlation between duration of treatment and change in height Z scores (r = -0.08 for beginning vs end change, r = 0.01 for end vs 24 months later change). Among the 59 ADHD cases treated for ≥3 years, there was a clinically insignificant decrease in mean Z score from beginning (0.48) to end (0.33) of treatment (P = .06).

CONCLUSIONS

Our findings suggest that ADHD treatment with stimulant medication is not associated with differences in adult height or significant changes in growth.

Childhood ADHD and risk for substance dependence in adulthood: a longitudinal, population-based study

Background

Adolescents with attention-deficit/hyperactivity disorder (ADHD) are known to be at significantly greater risk for the development of substance use disorders (SUD) compared to peers. Impulsivity, which could lead to higher levels of drug use, is a known symptom of ADHD and likely accounts, in part, for this relationship. Other factors, such as a biologically increased susceptibility to substance dependence (addiction), may also play a role.

Objective

This report further examines the relationships between childhood ADHD, adolescent- onset SUD, and substance abuse and substance dependence in adulthood.

Method

Individuals with childhood ADHD and non-ADHD controls from the same population-based birth cohort were invited to participate in a prospective outcome study. Participants completed a structured neuropsychiatric interview with modules for SUD and a psychosocial questionnaire. Information on adolescent SUD was obtained retrospectively, in a previous study, from medical and school records. Associations were summarized using odds ratios (OR) and 95% CIs estimated from logistic regression models adjusted for age and gender.

Results

A total of 232 ADHD cases and 335 non-ADHD controls participated (mean age, 27.0 and 28.6 years, respectively). ADHD cases were more likely than controls to have a SUD diagnosed in adolescence and were more likely to have alcohol (adjusted OR 14.38, 95% CI 1.49–138.88) and drug (adjusted OR 3.48, 95% CI 1.38–8.79) dependence in adulthood. The subgroup of participating ADHD cases who did not have SUD during adolescence were no more likely than controls to develop new onset alcohol dependence as adults, although they were significantly more likely to develop new onset drug dependence.

Conclusions

Our study found preliminary evidence that adults with childhood ADHD are more susceptible than peers to developing drug dependence, a disorder associated with neurological changes in the brain. The relationship between ADHD and alcohol dependence appears to be more complex.

ADHD and learning disabilities in former late preterm infants: a population-based birth cohort

BACKGROUND AND OBJECTIVE

Previous studies suggest that former late preterm infants are at increased risk for learning and behavioral problems compared with term infants. These studies have primarily used referred clinical samples of children followed only until early school age. Our objective was to determine the cumulative incidence of attention deficit/hyperactivity disorder (ADHD) and learning disabilities (LD) in former late preterm versus term infants in a population-based birth cohort.

METHODS

Subjects included all children born 1976 to 1982 in Rochester, MN who remained in the community after 5 years. This study focused on the comparison of subjects in 2 subgroups, late preterm (34 to <37 weeks) and term (37 to <42 weeks). School and medical records were available to identify individuals who met research criteria for ADHD and LD in reading, written language, and math. The Kaplan-Meier method was used to estimate the cumulative incidence of each condition by 19 years of age. Cox models were fit to evaluate the association between gestational age group and condition, after adjusting for maternal education and perinatal complications.

RESULTS

We found no statistically significant differences in the cumulative incidence of ADHD or LD between the late preterm (N = 256) versus term (N = 4419) groups: ADHD (cumulative incidence by age 19 years, 7.7% vs 7.2%; P = .84); reading LD (14.2% vs 13.1%; P = .57); written language LD (13.5% vs 15.7%; P = .36), and math LD (16.1% vs 15.5%; P = .89).

CONCLUSIONS

These data from a population-based birth cohort indicate that former late preterm infants have similar rates of LD and ADHD as term infants.

Incidence of enuresis and encopresis among children with attention-deficit/hyperactivity disorder in a population-based birth cohort

OBJECTIVE

This study reports the incidence of enuresis and encopresis among children with attention-deficit/hyperactivity disorder (ADHD) versus those without ADHD.

METHODS

Subjects included 358 children (74.5% boys) with research-identified ADHD from a 1976 to 1982 population-based birth cohort (n = 5718) and 729 (75.2% boys) non-ADHD control subjects from the same birth cohort, matched by gender and age. All subjects were retrospectively followed from birth until a diagnosis of enuresis or encopresis was made or last follow-up before 18 years of age. The complete medical record for each subject was reviewed to obtain information on age of initial diagnosis of an elimination disorder, frequency and duration of symptoms, and identification of exclusionary criteria specified by DSM-IV, with confirmation of the diagnosis by expert consensus.

RESULTS

Children with ADHD were 2.1 (95% confidence interval [CI], 1.3-3.4; P = .002) times more likely to meet DSM-IV criteria for enuresis than non-ADHD controls; they were 1.8 (95% CI, 1.2-2.7; P = .006) times more likely to do so than non-ADHD controls when less stringent criteria for a diagnosis of enuresis were employed. Though not significant, children with ADHD were 1.8 (95% CI, 0.7-4.6; P = .23) times more likely to meet criteria for encopresis than non-ADHD controls. The relative risk was 2.0 (95% CI, 1.0-4.1; P = .05) when a less stringent definition for encopresis was utilized.

CONCLUSIONS

Children with ADHD are more likely than their peers without ADHD to develop enuresis with a similar trend for encopresis.

Mortality, ADHD, and psychosocial adversity in adults with childhood ADHD: a prospective study

OBJECTIVE

We examined long-term outcomes of attention-deficit/hyperactivity disorder (ADHD) in a population-based sample of childhood ADHD cases and controls, prospectively assessed as adults.

METHODS

Adults with childhood ADHD and non-ADHD controls from the same birth cohort (N = 5718) were invited to participate in a prospective outcome study. Vital status was determined for birth cohort members. Standardized mortality ratios (SMRs) were constructed to compare overall and cause-specific mortality between childhood ADHD cases and controls. Incarceration status was determined for childhood ADHD cases. A standardized neuropsychiatric interview was administered.

RESULTS

Vital status for 367 childhood ADHD cases was determined: 7 (1.9%) were deceased, and 10 (2.7%) were currently incarcerated. The SMR for overall survival of childhood ADHD cases versus controls was 1.88 (95% confidence interval [CI], 0.83-4.26; P = .13) and for accidents only was 1.70 (95% CI, 0.49-5.97; P = .41). However, the cause-specific mortality for suicide only was significantly higher among ADHD cases (SMR, 4.83; 95% CI, 1.14-20.46; P = .032). Among the childhood ADHD cases participating in the prospective assessment (N = 232; mean age, 27.0 years), ADHD persisted into adulthood for 29.3% (95% CI, 23.5-35.2). Participating childhood ADHD cases were more likely than controls (N = 335; mean age, 28.6 years) to have ≥1 other psychiatric disorder (56.9% vs 34.9%; odds ratio, 2.6; 95% CI, 1.8-3.8; P < .01).

CONCLUSIONS

Childhood ADHD is a chronic health problem, with significant risk for mortality, persistence of ADHD, and long-term morbidity in adulthood.

Early speech-language impairment and risk for written language disorder: a population-based study

OBJECTIVE

To compare risk of written language disorder (WLD) in children with and without speech-language impairment (S/LI) from a population-based cohort.

METHODS

Subjects included all children born between 1976 and 1982 in Rochester, Minnesota, who remained in the community after age 5 years (n = 5718). Records from public and private schools, medical agencies, and tutoring services were abstracted. S/LI was determined based on eligibility criteria for an individualized education plan. Incident cases of WLD were identified by research criteria using regression-based discrepancy, non-regression-based discrepancy, and low-achievement formulas applied to cognitive and academic achievement tests. Incidence of WLD (with or without reading disorder [RD]) was compared between children with and without S/LI. Associations were summarized using hazard ratios.

RESULTS

Cumulative incidence of WLD by age 19 years was significantly higher in children with S/LI than in children without S/LI. The magnitude of association between S/LI and WLD with RD was significantly higher for girls than for boys. This was not true for the association between S/LI and WLD without RD.

CONCLUSIONS

Risk for WLD is significantly increased among children with S/LI compared with children without S/LI based on this population-based cohort. Early identification and intervention for children at risk for WLD could potentially influence academic outcomes.

Childhood ADHD is strongly associated with a broad range of psychiatric disorders during adolescence: a population-based birth cohort study

BACKGROUND

To evaluate associations between attention-deficit/hyperactivity disorder (ADHD) and comorbid psychiatric disorders using research-identified incident cases of ADHD and population-based controls.

METHODS

Subjects included a birth cohort of all children born 1976-1982 remaining in Rochester, MN after age five (n = 5,718). Among them we identified 379 ADHD incident cases and 758 age-gender matched non-ADHD controls, passively followed to age 19 years. All psychiatric diagnoses were identified and abstracted, but only those confirmed by qualified medical professionals were included in the analysis. For each psychiatric disorder, cumulative incidence rates for subjects with and without ADHD were estimated using the Kaplan-Meier method. Corresponding hazard ratios (HR) were estimated using Cox models adjusted for gender and mother's age and education at the subject's birth. The association between ADHD and the likelihood of having an internalizing or externalizing disorder was summarized by estimating odds ratios (OR).

RESULTS

Attention-deficit/hyperactivity disorder was associated with a significantly increased risk of adjustment disorders (HR = 3.88), conduct/oppositional defiant disorder (HR = 9.54), mood disorders (HR = 3.67), anxiety disorders (HR = 2.94), tic disorders (HR = 6.53), eating disorders (HR = 5.68), personality disorders (HR = 5.80), and substance-related disorders (HR = 4.03). When psychiatric comorbidities were classified on the internalization-externalization dimension, ADHD was strongly associated with coexisting internalizing/externalizing (OR = 10.6), or externalizing-only (OR = 10.0) disorders.

CONCLUSION

This population-based study confirms that children with ADHD are at significantly increased risk for a wide range of psychiatric disorders. Besides treating the ADHD, clinicians should identify and provide appropriate treatment for psychiatric comorbidities.

Evaluation of the ability of neurobiological, neurodevelopmental and socio-economic variables to predict cognitive outcome in premature infants

BACKGROUND

When developed in the 1990s, the Neurobiologic Risk Score (NBRS) and Neurodevelopmental Risk Exam (NRE) correlated well with developmental outcomes in premature infants. Given recent advances in neonatology, we assessed their present ability to predict cognitive outcome, alone and combined with socio-economic factors.

METHODS

One hundred and twenty-nine neonates <32 weeks gestational age were assessed at 6, 12 and/or 24 months corrected age with the Cognitive Adaptive Test/Clinical Linguistic and Auditory Milestone Scale (CAT/CLAMS). Indices of socio-economic status included maternal education and marital status.

RESULTS

At 24 months corrected age (n= 67), the NBRS (r=-0.5), maternal education (r= 0.46) and marital status (r= 0.37) correlated with the CAT/CLAMS. These correlations increased when NBRS and maternal education were combined (r= 0.63) and when specific NBRS components (intraventricular haemorrhage, periventricular leukomalacia, seizures) and maternal education were combined (r= 0.66).

CONCLUSIONS

In the contemporary neonatal intensive care unit, measures used to predict cognitive outcome should incorporate both neurobiological risk factors and socio-economic variables.

Attention-deficit/hyperactivity disorder after early exposure to procedures requiring general anesthesia

OBJECTIVE

To study the association between exposure to procedures performed under general anesthesia before age 2 years and development of attention-deficit/hyperactivity disorder (ADHD).

PATIENTS AND METHODS

Study patients included all children born between January 1, 1976, and December 31, 1982, in Rochester, MN, who remained in Rochester after age 5. Cases of ADHD diagnosed before age 19 years were identified by applying stringent research criteria. Cox proportional hazards regression assessed exposure to procedures requiring general anesthesia (none, 1, 2 or more) as a predictor of ADHD using a stratified analysis with strata based on a propensity score including comorbid health conditions.

RESULTS

Among the 5357 children analyzed, 341 ADHD cases were identified (estimated cumulative incidence, 7.6%; 95% confidence interval [CI], 6.8%-8.4%). For children with no postnatal exposure to procedures requiring anesthesia before the age of 2 years, the cumulative incidence of ADHD at age 19 years was 7.3% (95% CI, 6.5%-8.1%). For single and 2 or more exposures, the estimates were 10.7% ( 95% CI, 6.8%-14.4%) and 17.9% ( 95% CI, 7.2%-27.4%), respectively. After adjusting for gestational age, sex, birth weight, and comorbid health conditions, exposure to multiple (hazard ratio, 1.95; 95% CI, 1.03-3.71), but not single (hazard ratio,1.18; 95% CI, 0.79-1.77), procedures requiring general anesthesia was associated with an increased risk for ADHD.

CONCLUSION

Children repeatedly exposed to procedures requiring general anesthesia before age 2 years are at increased risk for the later development of ADHD even after adjusting for comorbidities.

Written-language disorder among children with and without ADHD in a population-based birth cohort

OBJECTIVE

We determined the incidence of written-language disorder (WLD) among children with and without attention-deficit/hyperactivity disorder (ADHD) in a population-based birth cohort.

METHODS

Subjects included a birth cohort of all children born in 1976-1982 who remained in Rochester, Minnesota, after 5 years of age (N = 5718). Information from medical, school, and private tutorial records was abstracted. Cumulative incidences of WLD with or without reading disability (RD), identified with any of 3 formulas, among children with and without ADHD and hazard ratios (HRs) were calculated.

RESULTS

For both genders, the cumulative incidence of WLD by 19 years of age was significantly higher for children with ADHD than for children without ADHD (boys: 64.5% vs 16.5%; girls: 57.0% vs 9.4%). The magnitude of association between ADHD and WLD with RD was significantly higher for girls than for boys (adjusted HR: girls: 9.8; boys: 4.2; P < .001). However, this was not true for WLD without RD (adjusted HR: girls: 7.4; boys: 6.6; P = .64).

CONCLUSIONS

ADHD is strongly associated with an increased risk of WLD (with or without RD) for both boys and girls. Girls with ADHD are at higher risk of having WLD with RD compared with boys with ADHD, whereas boys and girls are at the same risk of having WLD without RD.

Developmental and behavioral disorders through the life span

Developmental and behavioral disorders including intellectual disability, learning disabilities, and attention-deficit/hyperactivity disorder are highly prevalent, chronic health conditions. Despite being versed in caring for children with these conditions, pediatricians might be less prepared for challenging questions from families about the long-term course of these conditions and what can be done to improve outcomes. Through this state-of-the-art review, we provide clinicians with an understanding of the course of these conditions and adult outcomes in several areas including vocational, social, and health domains. We also provide a review of the most current research examining factors that predict or mediate adult outcomes for people with intellectual disability, learning disabilities, and attention-deficit/hyperactivity disorder. On the basis of the current literature, we offer practice recommendations aimed at optimizing adult outcomes for those with these disorders.

Gender, attention-deficit/hyperactivity disorder, and reading disability in a population-based birth cohort

OBJECTIVE

To determine the incidence of reading disability (RD) among children with and without research-identified attention-deficit/hyperactivity disorder (ADHD), separately according to gender, in a population-based birth cohort.

METHOD

Subjects included all children born in 1976-1982 remaining in Rochester, Minnesota, after 5 years of age (n=5718). Information from medical, school, and private tutorial records was abstracted. Cumulative incidence of RD, by any of 3 RD formulas, in children with and without ADHD and corresponding hazard ratios (HRs) were calculated separately according to gender.

RESULTS

Cumulative incidence of RD by the age of 19 years was significantly higher in children with ADHD (51% in boys, 46.7% in girls) compared with those without ADHD (14.5% in boys, 7.7% in girls). Among children with ADHD, the risk for RD was similar in boys versus girls (HR: 1.0). However, among children without ADHD, boys were 2.0 times more likely than girls to meet RD criteria. Among girls, the HR for the risk for RD associated with ADHD (versus those without ADHD) was 8.1 (95% confidence interval: 5.7-11.5), which was significantly higher than the corresponding HR among boys (3.9 [95% confidence interval: 3.2-4.9]).

CONCLUSIONS

The risk for RD is significantly greater among children with ADHD compared with those without ADHD. Among children with ADHD, the risk for RD is the same for boys and girls. However, among children without ADHD, boys are more at risk for RD than girls. Among girls, the magnitude of increased risk for RD associated with ADHD is nearly twice that among boys, because girls without ADHD are less likely to have RD than boys without ADHD.

Epilepsy in children with attention-deficit/hyperactivity disorder

Previous studies have suggested a higher incidence of symptoms of attention-deficit/hyperactivity disorder (ADHD) in children with epilepsy, but few have investigated epilepsy in children with ADHD. The objective here was to compare the incidence and characteristics of epilepsy among population-based, research identified cohorts of children with (n = 358) and without ADHD (n = 728), based on medical record review to age 20 years. Data abstracted included characteristics of seizures, testing, and treatment. Cases were 2.7 times more likely than controls to have epilepsy (95% CI = 0.94-7.76; P = 0.066), had earlier seizure onset (median age, 5.5 vs 15 years; P = 0.020), and exhibited a trend toward more frequent seizures (more than monthly, 63% vs 17%). Among children who met the research criteria for ADHD, those with epilepsy tended to be less likely to have received a clinical diagnosis of ADHD (63% vs 89%; P = 0.052) or to be treated with stimulants (50% vs 85%; P = 0.025). The findings suggest a strong trend toward a higher incidence of epilepsy among children with ADHD than among children without ADHD. Epilepsy in children with ADHD appears to be more severe than in those without. Finally, there appears to be a reluctance to diagnose and initiate treatment for ADHD in children with epilepsy.

Incidence of gastrointestinal symptoms in children with autism: a population-based study

OBJECTIVE

To determine whether children with autism have an increased incidence of gastrointestinal symptoms compared with matched control subjects in a population-based sample.

DESIGN/METHODS

In a previous study including all of the residents of Olmsted County, Minnesota, aged <21 years between 1976 and 1997, we identified 124 children who fulfilled criteria on the basis of Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, for a research diagnosis of autism. Two matched control subjects were identified for each case subject. Through the Rochester Epidemiology Project, all medical diagnoses, are indexed for computerized retrieval. Gastrointestinal diagnoses before 21 years of age were grouped into 5 categories: (1) constipation; (2) diarrhea; (3) abdominal bloating, discomfort, or irritability; (4) gastroesophageal reflux or vomiting; and (5) feeding issues or food selectivity. The cumulative incidence of each category was calculated by using the Kaplan-Meier method. Cox proportional hazards models were fit to estimate the risk ratios (case subjects versus control subjects) and corresponding 95% confidence intervals.

RESULTS

Subjects were followed to median ages of 18.2 (case subjects) and 18.7 (control subjects) years. Significant differences between autism case and control subjects were identified in the cumulative incidence of constipation (33.9% vs 17.6%) and feeding issues/food selectivity (24.5% vs 16.1). No significant associations were found between autism case status and overall incidence of gastrointestinal symptoms or any other gastrointestinal symptom category.

CONCLUSIONS

As constipation and feeding issues/food selectivity often have a behavioral etiology, data suggest that a neurobehavioral rather than a primary organic gastrointestinal etiology may account for the higher incidence of these gastrointestinal symptoms in children with autism.

The forgotten learning disability: epidemiology of written-language disorder in a population-based birth cohort (1976-1982), Rochester, Minnesota

OBJECTIVE

The aim of this study was to report the incidence rates and other epidemiologic characterizations of written-language disorder. There have been no epidemiologic studies on the incidence of written-language disorder in the United States, and the use of a population-based birth cohort, longitudinally followed, is the most powerful method for reaching this objective.

METHODS

In this population-based, retrospective birth cohort study, subjects included 5718 children born between 1976 and 1982 in Rochester, Minnesota, who remained in the community after 5 years of age. Records from all public and nonpublic schools, medical facilities, and private tutorial services were reviewed and results of all individually administered IQ and achievement tests, and extensive medical, educational, and socioeconomic information, were collected. The essential features of writing problems from the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision were included in our operationalized definition of written-language disorder. Written-language disorder incident cases were established by using research criteria based on 3 formulas (regression-based discrepancy, nonregression-based discrepancy, and low achievement).

RESULTS

Cumulative incidence rates of written-language disorder varied from 6.9% to 14.7% depending on the formula. Boys were 2 to 3 times more likely to be affected than girls regardless of the formula. Among all written-language disorder cases (N = 806), 25% (n = 203) had written-language disorder without a reading disability. Specifics of the writing problems were identified for 87% (n = 702) of written-language disorder cases.

CONCLUSIONS

In this population-based birth cohort of school-aged children, written-language disorder was at least as frequent as reading disabilities and significantly more frequent among boys than girls.

The incidence of clinically diagnosed versus research-identified autism in Olmsted County, Minnesota, 1976-1997: results from a retrospective, population-based study

Autism prevalence studies have often relied on administrative prevalence or clinical diagnosis as case-identification strategies. We report the incidence of clinical diagnoses of autism spectrum disorders (ASD), versus research-identified autism among residents of Olmsted County, Minnesota, age < or =21 years, from 1976-1997. The incidence of clinically diagnosed ASD (with 95% CI) was 1.5 per 100,000 (0.0-3.7) in 1980-1983 and 33.1 (22.8-43.3) in 1995-1997, a 22.1-fold increase. In contrast, the incidence of research-identified autism increased from 5.5 (1.4-9.5) per 100,000 to 44.9 (32.9-56.9), an 8.2-fold increase. Only 46.8% of research-identified cases received a clinical diagnosis of ASD. These findings demonstrate the potential for misleading interpretation of results from epidemiologic studies that rely on clinical diagnosis of autism to identify cases.

Prevalence, recognition, and treatment of attention-deficit/hyperactivity disorder in a national sample of US children

OBJECTIVE

To determine the US national prevalence of attention-deficit/hyperactivity disorder (ADHD) and whether prevalence, recognition, and treatment vary by socioeconomic group.

DESIGN

Cross-sectional survey.

SETTING

Nationally representative sample of the US population from 2001 to 2004.

PARTICIPANTS

Eight- to 15-year-old children (N = 3082) in the National Health and Nutrition Examination Survey.

MAIN OUTCOME MEASURES

The Diagnostic Interview Schedule for Children (caregiver module) was used to ascertain the presence of ADHD in the past year based on Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) (DSM-IV) criteria. Prior diagnosis of ADHD by a health professional and ADHD medication use were assessed by caregiver report.

RESULTS

Of the children, 8.7% met DSM-IV criteria for ADHD. The poorest children (lowest quintile) were more likely than the wealthiest (highest quintile) to fulfill criteria for ADHD (adjusted odds ratio [AOR], 2.3; 95% confidence interval [CI], 1.4-3.9). Among children meeting DSM-IV ADHD criteria, 47.9% had a prior diagnosis of ADHD and 32.0% were treated consistently with ADHD medications during the past year. Girls were less likely than boys to have their disorder identified (AOR, 0.3; 95% CI, 0.1-0.8), and the wealthiest children were more likely than the poorest to receive regular medication treatment (AOR, 3.4; 95% CI, 1.3-9.1).

CONCLUSIONS

Of US children aged 8 to 15 years, 8.7%, an estimated 2.4 million, meet DSM-IV criteria for ADHD. Less than half of children meeting DSM-IV criteria report receiving either a diagnosis of ADHD or regular medication treatment. Poor children are most likely to meet criteria for ADHD yet are least likely to receive consistent pharmacotherapy.

Modifiers of long-term school outcomes for children with attention-deficit/hyperactivity disorder: does treatment with stimulant medication make a difference? Results from a population-based study

OBJECTIVE

The purpose of this study was to describe the significance of potential modifiers of long-term school outcomes among children with attention-deficit/hyperactivity disorder (AD/HD), including treatment with stimulant medication.

METHODS

Subjects included 370 children with research-identified AD/HD from a 1976-1982 population-based birth cohort (N = 5718). In a companion study, the complete school record for each subject was reviewed to obtain information on reading achievement, absenteeism, grade retention, and school dropout. Data on type of stimulant, dose, age at initiation of treatment, and start/stop dates were collected from medical and school records, available for all subjects.

RESULTS

Treatment with stimulants was associated with decreased rates of absenteeism; longer duration of treatment was also associated with decreased absenteeism rates. There was a modest positive correlation (r = .15, p = .012) between average daily stimulant dose and last reading score. Cases treated with stimulants were 1.8 times less likely to subsequently be retained a grade (95% confidence interval: 1.01-3.2; p = .047). The proportion of school dropout was similar between treated and not treated cases (22.2% vs 25.8%, p = .54). Other potential modifiers of school outcomes (sociodemographic risk factors, presence of comorbid learning or psychiatric disorders, and receipt of special educational services) were also examined and found to be associated with poorer outcomes.

CONCLUSIONS

In this birth cohort, stimulant treatment of children with AD/HD was associated with improved reading achievement, decreased school absenteeism, and decreased grade retention. This study provides support for efforts to ensure that children with AD/HD receive appropriate long-term medical treatment.

Long-term school outcomes for children with attention-deficit/hyperactivity disorder: a population-based perspective

OBJECTIVE

The purpose of this study was to compare long-term school outcomes (academic achievement in reading, absenteeism, grade retention, and school dropout) for children with attention-deficit/hyperactivity disorder (AD/HD) versus those without AD/HD.

METHODS

Subjects included 370 children with research-identified AD/HD from a 1976-1982 population-based birth cohort (N = 5718) and 740 non-AD/HD control subjects from the same birth cohort, matched by gender and age. All subjects were retrospectively followed from birth until a median age of 18.4 years (AD/HD cases) or 18.3 years (non-AD/HD controls). The complete school record for each subject was reviewed to obtain information on reading achievement (last available California Achievement Test reading score), absenteeism (number/percentage of school days absent at each grade level), grade retention (having to repeat an entire grade in the subsequent school year), and school dropout (failure to graduate from high school).

RESULTS

Median reading achievement scores at age 12.8 years (expressed as a national percentile) were significantly different for AD/HD cases and non-AD/HD controls (45 vs 73). Results were similar for both boys and girls with AD/HD. Median percentage of days absent was statistically significantly higher for children with AD/HD versus those without AD/HD, although the difference was relatively small in absolute number of days absent. Subjects with AD/HD were three times more likely to be retained a grade. Similarly, subjects with AD/HD were 2.7 times more likely to drop out before high school graduation (22.9%) than non-AD/HD controls (10.0%).

CONCLUSIONS

The results of this population-based study clearly demonstrate the association between AD/HD and poor long-term school outcomes.

Comparison of the validity of direct pediatric developmental evaluation versus developmental screening by parent report

To compare the validity of direct pediatric developmental evaluation with developmental screening by parent report, parents completed a developmental screen (the Child Development Review), a pediatrician performed a direct developmental evaluation (Capute Scales), and a psychologist administered the Bayley Scales of Infant Development to a group of 30-month-old children. The agreement between these instruments was tested. All developmental quotient scores derived from the Capute Scales were more highly correlated with concurrent Bayley Mental Development Index scores than developmental quotient scores derived from the Child Development Review. Differences between developmental quotient scores derived from the Capute Scales and corresponding Bayley Mental Development Index scores were significantly smaller than those derived from the Child Development Review. Thus, direct pediatric developmental evaluation more reliably predicted concurrent Mental Development Index scores at 30 months of age than developmental screening by parent report. Increased emphasis on training of pediatric health care providers in direct developmental evaluation should be considered.

Autism: a review of the state of the science for pediatric primary health care clinicians

Autism is a complex neurodevelopmental disorder characterized by impaired reciprocal social interaction, impaired communication, and restricted, repetitive, or stereotyped behaviors. Autism seems to affect more children than was previously believed, although this phenomenon may be due to broadening of the diagnostic criteria and increased awareness of the condition. Recent research has clearly indicated the importance of early identification, since early intensive treatment is associated with better long-term outcome. There are many controversies and competing theories about the etiology and treatment of autism, often leaving families confused about the best course of treatment and intervention. Pediatric primary health care clinicians have an important role in both the early identification and ongoing management of children with autism. It is, therefore, essential that primary care clinicians have up-to-date information about the science of autism.

Developmental dissociation, deviance, and delay: Occurrence of attention-deficit-hyperactivity disorder in individuals with and without borderline-to-mild intellectual disability

A neurodevelopmental model for understanding the spectrum of developmental disabilities postulates that developmental delay, dissociation, and deviance reflect underlying central nervous system dysfunction. In this study, we determined the occurrence of the dissociated and developmentally deviant behavioral profile of attention-deficit-hyperactivity disorder (ADHD) among children with and without developmental cognitive delays (borderline-to-mild intellectual disability) in a population-based birth cohort (n = 5718). Among the 70 children identified to have borderline-to-mild intellectual disability, 30% (n = 21; 7 females, 14 males) met research criteria for ADHD, compared to only 6.4% of children without intellectual disability (n = 358; 88 females, 270 males). The odds ratio for comorbid ADHD for children with versus without borderline-to-mild intellectual disability was 6.3 (95% confidence interval: 3.7-10.6; p < 0.001). These data illustrate that developmental dissociation and/or deviance, as represented by ADHD, are more likely to occur in the context of developmental delay, represented by borderline-to-mild intellectual disability.

Emergency department use and costs for youth with attention-deficit/hyperactivity disorder: associations with stimulant treatment

OBJECTIVE

To investigate whether, among youth with attention-deficit/hyperactivity disorder (ADHD), stimulant treatment is associated with reduced emergency department (ED) use and medical costs.

METHODS

We previously reviewed the complete and detailed school and medical records of all individuals born 1976-1982 in Rochester, Minn, to identify those who met criteria for ADHD between age 5 years and emigration from the area. Stimulant treatment (all start/stop dates, dosages) was also abstracted. This study followed birth cohort members with ADHD in provider-linked billing data from January 1, 1987 (billing data first available), to age 18 for outcomes: ED visits, ED costs, and medical costs. For each outcome, we analyzed associations with 1) any stimulants (yes/no), 2) proportion of follow-up time on stimulants, and 3) among those treated with stimulants, periods on versus off stimulants.

RESULTS

Of 313 youth with ADHD, 231 (74%) received any stimulants; treatment duration ranged from 14 days to 11.8 years. Treated and untreated youth were similar with respect to median annual ED visits (0.5 vs 0.5) and medical costs (661 US dollars vs 741 US dollars) (P > .05); however, increasing proportion of follow-up on stimulants was associated with fewer ED visits (P= .02) and higher medical costs (P< .001). The 231 treated youth experienced an average of 3.7 periods on and off stimulants; while receiving stimulants, they exhibited fewer ED visits (P= .02), lower ED costs (P = .03), and higher medical costs (P< .001) compared with periods off stimulants.

CONCLUSIONS

Among youth with ADHD, extended stimulant treatment is associated with decreased ED visits and ED costs, but higher total medical costs.

Long-term stimulant medication treatment of attention-deficit/hyperactivity disorder: results from a population-based study

The purpose of this study was to offer detailed information about stimulant medication treatment provided throughout childhood to 379 children with research-identified attention-deficit hyperactivity disorder (ADHD) in the 1976-1982 Rochester, MN, birth cohort. Subjects were retrospectively followed from birth until a mean of 17.2 years of age. The complete medical record of each subject was reviewed. The history and results of each episode of stimulant treatment were compared by gender, DSM-IV subtype of ADHD, and type of stimulant medication. Overall, 77.8% of subjects were treated with stimulants. Boys were 1.8 times more likely than girls to be treated. The median age at initiation (9.8 years), median duration of treatment (33.8 months), and likelihood of developing at least one side effect (22.3%) were not significantly different by gender. Overall, 73.1% of episodes of stimulant treatment were associated with a favorable response. The likelihood of a favorable response was comparable for boys and girls. Treatment was initiated earlier for children with either ADHD combined type or ADHD hyperactive-impulsive type than for children with ADHD predominantly inattentive type and duration of treatment was longer for ADHD combined type. There was no association between DSM-IV subtype and likelihood of a favorable response or of side effects. Dextroamphetamine and methylphenidate were equally likely to be associated with a favorable response, but dextroamphetamine was more likely to be associated with side effects. These results demonstrate that the effectiveness of stimulant medication treatment of ADHD provided throughout childhood is comparable to the efficacy of stimulant treatment demonstrated in clinical trials.

Math learning disorder: incidence in a population-based birth cohort, 1976-82, Rochester, Minn

OBJECTIVE

To report the incidence of math learning disorder (Math LD) among school-aged children, overall and by gender. To compare incidence estimates obtained by using three different methods to identify Math LD cases. To assess the extent to which children manifest Math LD alone, versus Math LD with comorbid reading disorder.

METHODS

This is a population-based, retrospective, birth cohort study. Subjects included all children born 1976-82 who remained in Rochester, Minn after age 5 (N = 5718). Using records from all public and private schools, medical facilities, and private tutorial services, all individually administered intelligence quotient and achievement tests and extensive medical, educational, and socioeconomic information were abstracted. Math LD was established using research criteria based on 3 formulas (regression-based discrepancy, nonregression-based discrepancy, low achievement).

RESULTS

Cumulative incidence rates of Math LD by age 19 years varied from 5.9% to 13.8% according to the formula used. Boys were more likely to be affected than girls, with relative risk ratios from 1.6 to 2.2 depending on the formula applied. Many children with Math LD (35% to 56.7%, depending on the formula used to define Math LD) did not have a comorbid reading disorder.

CONCLUSIONS

These results, from a community-based birth cohort, suggest that Math LD is common among schoolchildren, and is significantly more frequent among boys than girls, regardless of definition. Many children with Math LD do not have an associated reading disorder.

Case definition in epidemiologic studies of AD/HD

PURPOSE

Propose a five-step multigating, multimodal procedure for research case definition and identification of attention-deficit/hyperactivity disorder (AD/HD) in population-based epidemiologic studies.

METHODS

Subjects included a birth cohort of all children born between 1976 and 1982 who remained in Rochester after age 5. Screening for AD/HD required 4 steps, using these sources: school/medical records, computerized diagnostic index, and private psychiatry records. In step 5, research criteria were applied to potential cases. The model for defining cases used combinations of three categories of information (DSM-IV, questionnaire, clinical diagnosis). Validity was tested by comparing medication treatment, substance abuse, school outcomes, and comorbidities between cases who did or did not meet DSM-IV criteria.

RESULTS

Among 5718 subjects, 1344 potential cases were identified; 379 met research criteria. No difference in gender, treatment, school outcome, or professional making clinical diagnoses was found between cases who did (N=228) and did not (N=151) meet DSM-IV criteria. However, cases not meeting DSM-IV criteria were more inattentive (33.8% vs. 17.1%; p < 0.001), older (age 12.8 vs. 10.5 years; p=0.01), with less substance abuse (15.2% vs. 26.3%; p < 0.001) and psychiatric comorbidities (43.1% vs. 54.4%; p=0.031).

CONCLUSIONS

If only DSM-IV criteria were applied, 151 cases would not have been identified. This study underscores the importance of using multiple sources and combinations of documented information for case definition and identification.

Psychostimulant treatment and risk for substance abuse among young adults with a history of attention-deficit/hyperactivity disorder: a population-based, birth cohort study

OBJECTIVE

The aim of this study was to evaluate the association between stimulant treatment and the risk for substance abuse among young adults with a childhood diagnosis of attention- deficit/hyperactivity disorder (ADHD).

METHODS

Subjects included 295 research-identified ADHD incidence cases treated with psychostimulant medication and 84 ADHD cases not treated with psychostimulants. These subjects are from a 1976-1982 population-based birth cohort, retrospectively, followed from birth until emigration, death, or last follow-up (mean = 17.2 years of follow-up). Medical and school records were reviewed for documented substance abuse and psychostimulant treatment. The association was evaluated using logistic regression models.

RESULTS

Socioeconomic characteristics at birth, and comorbidities, were similar between treated and untreated ADHD cases. Sixty (20.3%) of treated ADHD cases had documented substance abuse compared to 23 (27.4%) of cases not treated (OR = 0.7; 95% CI = 0.4-1.2). Among treated ADHD boys, 21.8% had substance abuse compared to 36.4% not-treated ADHD boys (OR = 0.5; 95% CI = 0.3-0.9). Among treated ADHD girls, 15.2% had substance abuse compared to 10.3% not-treated ADHD girls (OR = 1.5; 95% CI = 0.4-6.1).

CONCLUSION

While these results cannot demonstrate cause and effect, our findings indicate that psychostimulant treatment of childhood ADHD is associated with reduced risk for later substance abuse among boys with ADHD.

The incidence of autism in Olmsted County, Minnesota, 1976-1997: results from a population-based study

OBJECTIVE

To determine the incidence of autism among children in Olmsted County, Minnesota.

DESIGN

Through the Rochester Epidemiology Project, all inpatient and outpatient diagnoses are indexed for computerized retrieval. This computerized diagnostic index was used to identify children with any developmental disorder. A glossary of symptoms of autism was used to review medical and school records of these children for symptoms consistent with Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria for autistic disorder.

SETTING

Olmsted County, Minnesota. Subjects All residents of Olmsted County 21 years or younger between 1976 and 1997. Main Outcome Measure The incidence of research-identified autism based on DSM-IV criteria for autistic disorder.

RESULTS

The age-adjusted incidence of research-identified autism was 5.5 (95% confidence interval, 1.4-9.5) per 100 000 children from 1980 to 1983 and 44.9 (95% confidence interval, 32.9-56.9) from 1995 to 1997 (8.2-fold increase). This increase was confined to children younger than 10 years who were born after 1987.

CONCLUSIONS

The incidence of research-identified autism increased in Olmsted County from 1976 to 1997, with the increase occurring among young children after the introduction of broader, more precise diagnostic criteria, increased availability of services, and increased awareness of autism. Although it is possible that unidentified environmental factors have contributed to an increase in autism, the timing of the increase suggests that it may be due to improved awareness, changes in diagnostic criteria, and availability of services, leading to identification of previously unrecognized young children with autism.

Early life risk factors for attention-deficit/hyperactivity disorder: a population-based cohort study

OBJECTIVES

To Identify risk factors for attention-deficit/hyperactivity disorder (ADHD) and to determine whether these factors differ between boys and girls.

SUBJECTS AND METHODS

We conducted a case-control study of all children born between January 1, 1976, and December 31, 1982, in Olmsted County, Minnesota (N=5701), and examined birth certificates for risk factors for ADHD. Using school and medical records, we identified 305 children with ADHD. All children not identified with ADHD served as controls (N=5326). Risk factors that were assessed included demographic characteristics of both children and parents, as well as pregnancy, labor, and delivery characteristics, including the effect of a multiple birth and presence of pregnancy and delivery complications.

RESULTS

Pregnancy and labor characteristics, low birth weight, and presence of a twin birth were not associated with ADHD. Male sex (odds ratio [OR], 3.05; 95% confidence interval [CI], 2.34-3.98) was associated with an increased risk for ADHD, whereas high maternal and paternal education levels (high maternal education: OR, 0.57; 95% CI, 0.42-0.78; high paternal education: OR, 0.58; 95% CI, 0.49-0.78) were associated with a decreased risk for ADHD. In addition, low maternal and paternal education levels increased the risk for ADHD in boys more than in girls.

CONCLUSION

Male sex and low parental education levels are significant risk factors for ADHD. In addition, boys born to parents with low maternal and paternal education levels appear to be at an increased risk for ADHD compared with girls born to parents with low education levels.