Studying the epidemiology of attention-deficit hyperactivity disorder: screening method and pilot results

Analysis of Oral Health among ADHD-Affected and Non-ADHD Children in Gran Canaria

A study in Gran Canaria assessed the oral health of 53 children diagnosed with attention deficit hyperactivity disorder (ADHD) and 106 without ADHD, aged 6 to 16 years. Clinical data on dental caries, conservative treatments, and periodontal health were recorded. The main objective of this study was to investigate the prevalence of dental caries in children with ADHD and how their habits and behaviors contribute to their oral health status. The results showed that children with ADHD had a significant increase in dental caries, conservative treatments, and gingival bleeding. A connection with diet was found, though it did not have a negative impact. No increase in periodontal index was observed, and no significant relationship with diet, family factors, or breastfeeding was found. The evidence suggests that children with ADHD should undergo frequent dental check-ups to monitor oral health and receive education on the importance of the quality and frequency of tooth brushing. These findings highlight the need to address oral health in children with ADHD and the necessity for adequate dental care in this group.

Attention-deficit Disorder, Family Factors, and Oral Health Literacy

Introduction

Relationships amongst attention-deficit/hyperactivity disorder (ADHD), family factors, and oral health literacy (OHL) in adolescents are unclear. The objective of this research was to investigate whether family environment and signs of ADHD are associated with OHL at the onset of adolescence.

Methods

A cross-sectional study was performed with 448 twelve-year-old adolescents enrolled in schools in Cajazeiras, Brazil. Adolescents responded to an instrument measuring OHL (Brazilian version of the Rapid Estimate of Adult Literacy in Dentistry [BREALD-30]) and a validated questionnaire addressing family cohesion and adaptability (Family Adaptability and Cohesion Scales [FACES III]). Parents and teachers answered subscales of the Swanson, Nolan, and Pelham Questionnaire (SNAP-IV) and a socioeconomic questionnaire. Adjusted Poisson regression analysis was employed for the data analysis (P < .05).

Results

Greater OHL was found in adolescents with higher family cohesion scores (rate ratio [RR], 1.02; 95% confidence interval [CI], 1.01–1.03), those whose mothers had more than 8 years of schooling (RR, 1.07; 95% CI, 1.03–1.12), and those whose families earned more than the Brazilian minimum salary (RR, 1.08; 95% CI, 1.03–1.12). Higher family adaptability scores (RR, 0.99; 95% CI, 0.98–0.99) and more signs of ADHD (teachers’ reports) (RR, 0.95; 95% CI, 0.91–0.99) were associated with lower OHL.

Conclusions

OHL in adolescents was influenced by family adaptability and cohesion, signs of ADHD, maternal schooling, and family income.

Attention-deficit/hyperactivity disorder and oral health literacy exert an influence on the occurrence of dental caries in early adolescence

Little is known regarding the influence of psychosocial factors on dental caries at early adolescence. The study aimed to investigate associations between family environment, attention-deficit/hyperactivity disorder (ADHD) and oral health literacy (OHL) with dental caries experience in early adolescence. A cross-sectional study was conducted with a representative sample of 448 12-year-old adolescents at public and private schools in North-eastern Brazil. Parents/guardians and teachers answered the Brazilian version of the inattention and hyperactivity/impulsivity subscales (SNAP- IV) for the evaluation of ADHD and a sociodemographic questionnaire. An OHL instrument (BREALD-30) and the Family Adaptability and Cohesion Scales (FACES III) were administered to the adolescents. Caries experience (DMFT) was the dependent variable. Data analysis involved Poisson regression with robust variance (α = 5%). Adolescents with more symptoms of ADHD (teachers' reports) (RR: 1.73; 95% CI: 1.31-2.28), those with lower OHL (RR: 1.59; 95% CI: 1.01-2.51), those with a lower family income (RR: 1.38; 95% CI: 1.03-1.83), and those from families with a greater number of residents in the home (RR: 1.18; 95% CI: 1.06-1.31) had greater caries experience. Family adaptability and cohesion were not associated with caries experience. Dental caries experience in early adolescence was influenced by symptoms of ADHD, OHL, and sociodemographic factors.

Family cohesion and attention deficit exert an influence on visits to the dentist in early adolescence

OBJECTIVES

To determine whether family environment, signs of attention deficit/hyperactivity disorder (ADHD) and oral health literacy (OHL) are associated with visits to the dentist in adolescents.

METHODS

A school-based cross-sectional study was conducted with a representative sample of 448 12-year-old adolescents enrolled at schools in the city of Cajazeiras, Brazil. The adolescents answered a validated questionnaire addressing family cohesion and adaptability (FACES III), an OHL measure (Brazilian Rapid Estimate of Adult Literacy in Dentistry [BREALD-30]) and a questionnaire addressing the history of visits to the dentist and previous toothache experience. The parents answered a questionnaire addressing sociodemographic characteristics. Parents and teachers answered the inattention and hyperactivity/impulsivity subscales of the Swanson, Nolan & Pelham (SNAP-IV) questionnaire for the detection of signs of ADHD. Multiple Poisson regression with robust variance was used for data analysis (α = 5%).

RESULTS

The prevalence of having visited a dentist some time in life was higher among adolescents with enmeshed (PR = 1.08; 95% CI: 1.01-1.15) and connected (PR = 1.06; 95% CI: 1.01-1.13) families and those with attention deficit according to parents' reports (PR = 1.09; 95% CI: 1.04-1.14). A family income higher than the Brazilian minimum wage (PR = 1.06; 95% CI: 1.01-1.12) and toothache in the previous six months (PR = 1.05; 95% CI: 1.01-1.11) were also associated with the outcome.

CONCLUSION

Family cohesion and attention deficit according to parental reports influenced visits to the dentist among adolescents. In contrast, OHL was not associated with the outcome.

Overdiagnosis of Attention-Deficit/Hyperactivity Disorder in Children and Adolescents: A Systematic Scoping Review

IMPORTANCE

Reported increases in attention-deficit/hyperactivity disorder (ADHD) diagnoses are accompanied by growing debate about the underlying factors. Although overdiagnosis is often suggested, no comprehensive evaluation of evidence for or against overdiagnosis has ever been undertaken and is urgently needed to enable evidence-based, patient-centered diagnosis and treatment of ADHD in contemporary health services.

OBJECTIVE

To systematically identify, appraise, and synthesize the evidence on overdiagnosis of ADHD in children and adolescents using a published 5-question framework for detecting overdiagnosis in noncancer conditions.

EVIDENCE REVIEW

This systematic scoping review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) Extension for Scoping Reviews and Joanna Briggs Methodology, including the PRISMA-ScR Checklist. MEDLINE, Embase, PsychINFO, and the Cochrane Library databases were searched for studies published in English between January 1, 1979, and August 21, 2020. Studies of children and adolescents (aged ≤18 years) with ADHD that focused on overdiagnosis plus studies that could be mapped to 1 or more framework question were included. Two researchers independently reviewed all abstracts and full-text articles, and all included studies were assessed for quality.

FINDINGS

Of the 12 267 potentially relevant studies retrieved, 334 (2.7%) were included. Of the 334 studies, 61 (18.3%) were secondary and 273 (81.7%) were primary research articles. Substantial evidence of a reservoir of ADHD was found in 104 studies, providing a potential for diagnoses to increase (question 1). Evidence that actual ADHD diagnosis had increased was found in 45 studies (question 2). Twenty-five studies showed that these additional cases may be on the milder end of the ADHD spectrum (question 3), and 83 studies showed that pharmacological treatment of ADHD was increasing (question 4). A total of 151 studies reported on outcomes of diagnosis and pharmacological treatment (question 5). However, only 5 studies evaluated the critical issue of benefits and harms among the additional, milder cases. These studies supported a hypothesis of diminishing returns in which the harms may outweigh the benefits for youths with milder symptoms.

CONCLUSIONS AND RELEVANCE

This review found evidence of ADHD overdiagnosis and overtreatment in children and adolescents. Evidence gaps remain and future research is needed, in particular research on the long-term benefits and harms of diagnosing and treating ADHD in youths with milder symptoms; therefore, practitioners should be mindful of these knowledge gaps, especially when identifying these individuals and to ensure safe and equitable practice and policy.

Oral health of children and adolescents with or without attention deficit hyperactivity disorder (ADHD) living in residential care in rural Rhineland-Palatinate, Germany

Background

Attention deficit hyperactivity disorder (ADHD) is defined as childhood neurobehavioural disorder. Due to short attention span, oral hygiene and dental treatment of such individuals can be challenging. Aim of this study was to evaluate the oral health of children and adolescents with and without ADHD living in residential care in rural Rhineland-Palatinate, Germany.

Methods

Included in the study were 79 participants (male/female:58/21, age 9–15 years) living in residential care: 34 participants with ADHD and 45 participants without ADHD (control). Oral examination included the following parameters decayed, missing, filled teeth in the primary dentition (dmft), decayed, missing, filled surfaces/teeth in the secondary dentition (DMFS/DMFT), approximal plaque index (API), bruxism and orthodontic treatment. Additionally, oral hygiene, last dental visit and treatment performed, and dietary habits were assessed by questionnaire.

Results

There were no significant differences in dmft, API, bruxism and oral hygiene habits between groups. However, participants with ADHD tended to have higher DMFS/DMFT values than the control group. Ongoing orthodontic treatment was found more often in the control group. The ADHD group tended to consume acidic/sugary beverages and sweet snacks more often than the controls. Different treatments (control visit/prophylaxis, dental therapy, orthodontic treatment) were performed at the last dental visit in the two groups.

Conclusions

Within the limitations of this study, oral health was similar in children and adolescents with or without ADHD from the same residential care setting. Parents/guardians need instructions for better supervision of oral hygiene and dietary habits to improve the poor oral health of children with or without ADHD.

Dental caries in schoolchildren: influence of inattention, hyperactivity and executive functions

Attention-deficit/hyperactivity disorder (ADHD) is characterized by inappropriate levels of hyperactivity, impulsivity, and/or inattention. Individuals with ADHD may present limitations with regard to executive functions and performing activities that involve planning and/or attention/concentration. The aim of the study was to investigate the association between dental caries and signs of ADHD in a representative sample of schoolchildren. A representative sample of 851 schoolchildren aged seven to 12 years was randomly selected from public and private schools. Data acquisition involved a clinical dental examination for cavitated permanent and deciduous teeth using the DMFT/dmft indices. Neuropsychological evaluations, including the assessment of intelligence (Raven's Colored Progressive Matrix Test) and executive functions (Corsi Tapping Blocks tests and Digit Span test) were also performed. Parents/caregivers and teachers answered the SNAP-IV Questionnaire for the investigation of signs of inattention and hyperactivity in the family and school environment. Parents/caregivers also answered questionnaires addressing socioeconomic and socio-demographic characteristics. Descriptive analysis of the variables and Poisson regression with robust variance were performed. Parental reports of signs of inattention (PR: 1.28; p < 0.05) and hyperactivity (PR: 1.15; p < 0.05) were associated with a greater occurrence of caries. A better performance on the backward order of the Corsi Tapping Blocks tests (PR: 0.94; p < 0.05) and higher level of mother's schooling were associated with a lower frequency of caries. A better performance on executive function tasks was a protective factor against dental caries, whereas children considered inattentive and/or hyperactive by their parents had a higher prevalence rate of dental caries.

Attention-Deficit/Hyperactivity Disorder (ADHD): Interaction between socioeconomic status and parental history of ADHD determines prevalence

BACKGROUND

Many studies have reported a higher prevalence of Attention-Deficit/Hyperactivity Disorder (ADHD) among disadvantaged populations, but few have considered how parental history of ADHD might modify that relationship. We evaluated whether the prevalence of ADHD varies by socioeconomic status (SES) and parental history of ADHD in a population-sample of elementary school children age 6-14 years.

METHODS

We screened all children in grades 1-5 in 17 schools in one North Carolina (U.S.) county for ADHD using teacher rating scales and 1,160 parent interviews, including an ADHD structured interview (DISC). We combined parent and teacher ratings to determine DSM-IV ADHD status. Data analysis was restricted to 967 children with information about parental history of ADHD. SES was measured by family income and respondent education.

RESULTS

We found an interaction between family income and parental history of ADHD diagnosis (p = .016). The SES gradient was stronger in families without a parental history and weaker among children with a parental history. Among children without a parental history of ADHD diagnosis, low income children had 6.2 times the odds of ADHD (95% CI 3.4-11.3) as high income children after adjusting for covariates. Among children with a parental history, all had over 10 times the odds of ADHD as high income children without a parental history but the SES gradient between high and low income children was less pronounced [odds ratio (OR) = 1.4, 95% CI 0.6-3.5].

CONCLUSIONS

Socioeconomic status and parental history of ADHD are each strong risk factors for ADHD that interact to determine prevalence. More research is needed to dissect the components of SES that contribute to risk of ADHD. Future ADHD research should evaluate whether the strength of other environmental risk factors vary by parental history. Early identification and interventions for children with low SES or parental histories of ADHD should be explored.

Screening for ADHD in a Sample of Egyptian Adolescent School Students

OBJECTIVE

To screen for ADHD in a sample of Egyptian adolescent students, and study the distribution of different subtypes of ADHD, associated comorbidities, and sociodemographic correlates.

METHOD

A total of 925 adolescents were randomly selected and screened by the Conners-Wells' Adolescent Self-Report Scale-Short form (CASS:S), and potential cases were further assessed by the Kiddie Schedule for Affective Disorders and Schizophrenia-Present and Lifetime versions (K-SADS-PL).

RESULTS

A total of 87 students (9.4%) had potential ADHD diagnosis with evident preponderance in boys (13.8%, n = 58) than in girls (5.8%, n = 29) with a ratio of 2:1 ( p = .000, χ² = 17.328). The hyperactive-impulsive subtype comprised the majority of cases (54.7%, n = 41). Psychiatric comorbidity was invariably present (85.1%, n = 74). Nearly half the cases had poor academic achievement (43.7%, n = 34). Positive correlates included family history of psychiatric disorders, the order of birth, and parental disharmony.

CONCLUSION

ADHD is prevalent in Egyptian adolescents and is associated with high psychiatric comorbidity and a pronounced effect on academic performance.

ADHD Among Rural Southeastern Nigerian Primary School Children: Prevalence and Psychosocial Factors

OBJECTIVE

To determine the prevalence of ADHD among primary school pupils in a rural community in Southeastern Nigeria and to determine the psychosocial factors associated with the condition.

METHOD

One hundred eighty-one randomly selected participants had their teachers complete the school version of ADHD Rating Scale-IV. Their parents also completed a sociodemographic questionnaire, the clinical interview form for the child and adolescent ADHD patients, and home version of the ADHD Rating Scale-IV.

RESULTS

Twelve (6.6%) of the children met the criteria for diagnosis. A history of prolonged labor (odds ratio [OR] = 14.1; 95% confidence interval [CI] = [2.13, 93.1]), and parents' negative assessment of their marriages (OR = 0.1; CI = [0.017, 0.567]) were the most predominant factors which independently associated with the ADHD in the children.

CONCLUSION

There is, therefore, a need for the care of rural dwelling African children, who otherwise would have difficulties accessing health care that is concentrated in the cities.

Use of Multiple Informants to Identify Children at High Risk for ADHD in Turkish School-Age Children

OBJECTIVE

To examine the distribution of parent- and teacher-rated ADHD symptoms in a Turkish community sample to identify children at high risk for ADHD and to explore the psychosocial correlates of these high-risk children.

METHOD

An 18-item SNAP-IV (Swanson, Nolan, and Pelham) and a three-item impairment scale were completed by parents and teachers on 3,110 children between 7 and 14 years of age from three public schools in Istanbul.

RESULTS

Using various case definitions for ADHD, we observed a range of prevalence estimates based on parent (2.7%-9.6%) and teacher (2%-10.1%) reports. Teacher-identified ADHD was associated with low family income and low parental education; parent-identified ADHD was associated with perceived need for mental health treatment.

CONCLUSION

Statistically driven threshold on a symptom scale may overestimate the rate of high-risk children. Relying on one informant is likely to miss some children at high risk. As in clinical practice, therefore, data from multiple informants and evidence of impairment are essential for identifying ADHD.

[Time Trends in the Frequencies of ADHD and Stimulant Medication]

Time-trends in the frequencies of mental disorders represent specific challenges for the planning of services. The present review addresses the specific question whether or not there are time changes in terms of an increase of prevalence and incidence rates of attention-deficit hyperactivity disorders (ADHD) based on findings from international epidemiological studies from several decades. While there is no evidence that prevalence rates of ADHD have systematically increased, various national and international incidence studies on ADHD but also prevalence and incidence studies on prescribed medication indicate that the number of treated people with ADHD has increased significantly in the recent past. This increase remains even after adjusting for the general increase in the number of persons admitted to psychiatry for any disorder. Thus, the gap between those in need of treatment and those who actually receive treatment for ADHD has narrowed over time. However, after years of an increase, in recent years German studies dealing with prescriptions of medications have shown also a declining trend.

The Prevalence of ADHD in a Population-Based Sample

OBJECTIVE

Few studies of ADHD prevalence have used population-based samples, multiple informants, and Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV) criteria. Moreover, children who are asymptomatic while receiving ADHD medication often have been misclassified. Therefore, we conducted a population-based study to estimate the prevalence of ADHD in elementary school children using DSM-IV criteria.

METHOD

We screened 7,587 children for ADHD. Teachers of 81% of the children completed a DSM-IV checklist. We then interviewed parents using a structured interview (DISC). Of these, 72% participated. Parent and teacher ratings were combined to determine ADHD status. We also estimated the proportion of cases attributable to other conditions.

RESULTS

Overall, 15.5% of our sample met DSM- (4th ed.; text rev., DSM-IV-TR) criteria for ADHD (95% CI [14.6%, 16.4%]); 42% of cases reported no previous diagnosis. With additional information, other conditions explained 9% of cases.

CONCLUSION

The prevalence of ADHD in this population-based sample was considerably higher than 3% to 7%. To compare study results, the DSM criteria need standardization.

Attention-deficit/hyperactivity symptoms in preschool children from an e-waste recycling town: assessment by the parent report derived from DSM-IV

BACKGROUND

To investigate the attention-deficit/hyperactivity disorder (ADHD) status among preschool-aged children in Guiyu, an electronic waste (e-waste) recycling town in Guangdong, China.

METHODS

Two hundred and forty-three parents were surveyed regarding ADHD behaviors in their children (aged 3-7 years) based solely on the DSM-IV criteria. The peripheral blood samples were taken from these children to measure blood lead levels (BLLs) and blood cadmium levels (BCLs).

RESULTS

12.8% of children met the criteria for ADHD, of which the inattentive, hyperactive/impulsive and combined subtypes were 4.5%, 5.3% and 2.9% respectively. Of all children, 28.0% had BLLs ≥ 10 ug/dL and only 1.2% had BCLs ≥ 2 ug/L, levels conventionally considered high. Either modeled by univariate or multivariable analysis, the three ADHD scores (inattentive, hyperactive/impulsive and total scores) calculated from the Parent Rating Scale showed strong positive correlations with BLLs but not with BCLs. Furthermore, children with high BLLs had 2.4 times higher risk of ADHD than those with low BLLs (OR: 2.4 [95% CI: 1.1-5.2]). When each of the 18 categories on the Parent Rating Scale was separately analyzed, children with high BLLs had significant higher risks for positive ADHD symptoms than those with low BLLs in 12 of the 18 categories (ORs ranged from 2.1 [95% CI: 1.1-3.9] to 3.6 [95% CI: 1.7-7.5]).

CONCLUSIONS

This study suggests that environmental lead contamination due to e-waste recycling has an impact on neurobehavioral development of preschool children in Guiyu.

A Single-Dose, Two-Way Crossover, Bioequivalence Study of Dexmethylphenidate HCl with and without Food in Healthy Subjects

Attention deficit hyperactivity disorder (ADHD) in children is effectively treated by racemic oral methylphenidate (dl-MPH). The d-isomer (d-MPH) has been developed as an improved treatment for ADHD since only half the racemic dose is used. This study, performed in healthy subjects, assessed the effect of food on the pharmacokinetics of dexmethylphenidate hydrochloride (d-MPH HCl) in a single dose (2 x 10-mg tablets), two-way crossover with d-MPH administered to subjects in both a fasting state or after a high-fat breakfast. There were no serious or unexpected adverse events during the course of this study, with most events reported in comparable numbers of fed and fasted subjects. The bioequivalence of d-MPH was similar with or without food, with 90% confidence intervals of 88.2% to 104.6% and 105.9% to 118.2% for ln(C(max)) and ln[(AUC(0-infinity))], respectively. There was a marginal but statistically significant 1-hour increase in t(max) in the fed versus fasted state, reflecting an absorption delay. The rate of formation of the major metabolite, d-ritalinic acid (d-RA), was marginally decreased ( approximately 14%) after food. The extent of exposure to d-RA was similar (within 1.2%) between both treatments. There was a marginal but statistically significant difference in mean t(max) for d-RA between fed and fasted conditions, with peak concentration occurring 1.5 hours later after d-MPH administration with food. There was no measurable in vivo chiral inversion of d-MPH to l-MPH in plasma. In addition, the metabolism of d-MPH was stereospecific as d-MPH only produced d-RA. In summary, food had no substantial effect on the bioavailability of d-MPH, with an equivalent rate and extent of exposure obtained. Therefore, d-MPH can be administered without regard to food intake.

Acute and chronic methylphenidate alters prefrontal cortex neuronal activity recorded from freely behaving rats

Today's students around the world are striking deals to buy and sell the drug methylphenidate (MPD) for cognitive enhancement. Our knowledge on the effects of MPD on the brain is very limited. The present study was designed to investigate the acute and chronic effect of MPD on the prefrontal cortex (PFC) neurons. On experimental day 1 (ED1) recordings were obtained following saline injections and after 2.5 mg/kg MPD. On ED2 through ED6, daily single 2.5 mg/kg MPD was given followed by 3 washout days (ED7 to 9). On ED10, neuronal recordings were resumed from the same animal after saline and MPD injection similar to that obtained at ED1. Ninety PFC units were recorded, all responded to the initial MPD injection, 66 units (73%) increased their activity at ED10. Recordings were resumed for the 66 units that increased their firing rate at ED1, and following MPD injection 54 units (82%) exhibited significant increases in their baseline firing rates compared to ED1 baseline. When these 54 units were rechallenged (chronic effect) with MPD, 39/54 (72%) exhibited reduction in their firing rate which can be interpreted as tolerance. From the 24 (27%) units that responded to MPD at ED1 by decreasing their activity, 14 units (58%) exhibited a decrease in their baseline firing rates at ED10 compared to ED1 baseline. However, following MPD rechallenge of these 14 units, 11 units (79%) exhibited an increase in their firing rate which is interpreted as sensitization. In conclusion, all PFC units modified their neural baseline activity.

Nucleus accumbens neuronal activity in freely behaving rats is modulated following acute and chronic methylphenidate administration

Methylphenidate (MPD) is a psychostimulant that enhances dopaminergic neurotransmission in the central nervous system by using mechanisms similar to cocaine and amphetamine. The mode of action of brain circuitry responsible for an animal's neuronal response to MPD is not fully understood. The nucleus accumbens (NAc) has been implicated in regulating the rewarding effects of psychostimulants. The present study used permanently implanted microelectrodes to investigate the acute and chronic effects of MPD on the firing rates of NAc neuronal units in freely behaving rats. On experimental day 1 (ED1), following a saline injection (control), a 30 min baseline neuronal recording was obtained immediately followed by a 2.5 mg/kg i.p. MPD injection and subsequent 60 min neuronal recording. Daily 2.5 mg/kg MPD injections were given on ED2 through ED6 followed by 3 washout days (ED7 to ED9). On ED10, neuronal recordings were resumed from the same animal after a saline and MPD (rechallenge) injection exactly as obtained on ED1. Sixty-seven NAc neuronal units exhibited similar wave shape, form and amplitude on ED1 and ED10 and their firing rates were used for analysis. MPD administration on ED1 elicited firing rate increases and decreases in 54% of NAc units when compared to their baselines. Six consecutive MPD administrations altered the neuronal baseline firing rates of 85% of NAc units. MPD rechallenge on ED10 elicited significant changes in 63% of NAc units. These alterations in firing rates are hypothesized to be through mechanisms that include D1 and D2-like DA receptor induced cellular adaptation and homeostatic adaptations/deregulation caused by acute and chronic MPD administration.

Spatial attention, feature-based attention, and saccades: three sides of one coin?

The last three decades has seen a steady growth of neuroscience research aimed at understanding the functions and sources of top-down attentional modulation in the brain. This correlates with recognition that attention may be a necessary component of sensory systems to support natural behaviors in natural environments. Complexity and clutter are two of the most recognizable hallmarks of natural environments, which can simultaneously contain vitally important and completely irrelevant stimuli. Attention serves as an adaptive filter providing each sensory modality preferential processing routes for important stimuli while suppressing responses to distracters, thus optimizing use of limited neural resources. In other words, attention is the family of mechanisms by which organisms are able to effectively and selectively allocate limited neural resources to achieve specific behavioral goals. This review provides some historical context for considering attentional frameworks and modern neurophysiological attention research, focusing on visual attention. A taxonomy of common attentional effects and neural mechanisms is provided, along with consideration of the specific relationship between attention and saccade planning. We examine the validity of premotor theories of attention, which posit that attention and saccade planning are one and the same. While there is strong evidence that attention and oculomotor planning are similar, with shared neural substrates, there is also evidence that these two functions are not synonymous. Finally, we examine neurophysiological explanations for dysfunction in attention-deficit/hyperactivity disorder and the hypothesis that social impairment in autism spectrum disorders is partially attributable to perturbations of attentional control circuitry.

A framework for the assessment and treatment of sleep problems in children with attention-deficit/hyperactivity disorder

Children with attention-deficit/hyperactivity disorder (ADHD) have high rates of sleep problems and sleep disorders. It is critical that pediatricians assess for sleep problems during the course of ADHD assessment and when treating children with stimulant medication. Sleep must be considered in the differential diagnosis and in terms of comorbidity with ADHD. The most common sleep problem in children with ADHD is insomnia, and the first line of treatment should be the implementation of behavioral interventions rather than medication. More research is needed to determine if children with ADHD respond to behavioral interventions in a similar manner as typically developing children.

Transtorno do déficit de atenção e hiperatividade em crianças: uma revisão interdisciplinar

O presente artigo revisa criticamente o amplo escopo da literatura relacionada aos critérios diagnósticos, bases etiológicas e tratamentos farmacológico e comportamental do transtorno do déficit de atenção e hiperatividade (TDAH) em crianças. Foram consultadas as bases eletrônicas MedLine, Lilacs, PsycINFO e PubMed nas últimas três décadas. Os resultados dessa revisão apontam para uma predominância do critério diagnóstico baseado no Manual Diagnóstico e Estatístico das Doenças Mentais, bem como a necessidade de uma maior interação entre variáveis biológicas e comportamentais na compreensão das bases etiológicas e de tratamento deste transtorno. Sugestões para maximizar a eficácia desta interação são apresentadas e discutidas.

Prevalence of attention deficit hyperactivity disorder in schoolchildren in Athens, Greece. Association of ADHD subtypes with social and academic impairment

The aim of this study was to explore the prevalence of attention deficit hyperactivity disorder (ADHD) and social and academic impairment in 6- to 11-year-old children residents of Athens, Greece. We screened 603 elementary schoolchildren following grades first to sixth. A two-stage screening process was employed including a standardized ADHD test for teachers and the Teacher Report Form (TRF). Among the 603 children, 36 (6.0%) met the study criteria for ADHD. The estimated prevalence was 8% for boys and 3.8% for girls. The most prevalent subtype of ADHD was the combined type (3.8%), followed by the ADHD inattentive (1.7%) and the ADHD hyperactive-impulsive type (0.5%). The ADHD-combined type was strongly associated with clinical impairment in both areas of functioning (academic and social), where the ADHD inattentive subtype was found to be strongly associated with academic problems. The ADHD hyperactive-impulsive type was the less prevalent and the less impaired subtype in this study. None of the 36 children had been previously diagnosed as having ADHD or other primary disorder. In conclusion, the prevalence of ADHD among schoolchildren in Athens and the risk factors were found to be comparable to those reported in other countries worldwide. Additionally, impairment in social and academic functioning was strongly associated with the subtypes of the disorder.

The course of inattention and hyperactivity/impulsivity symptoms after foster placement

BACKGROUND

It is largely unknown whether symptoms of inattention and hyperactivity/impulsivity of foster children decline over time after placement and what the role of the quality and stability of the foster placement is on the course of attention-deficit hyperactivity disorder (ADHD) symptom trajectories. Longitudinal studies of normative trajectories of symptom types in nonreferred children may assist in appropriately diagnosing ADHD and designing the clinical treatment for foster children.

OBJECTIVE

We described average level and slope of inattention and hyperactivity/impulsivity symptoms over time and examined parental (biological and foster) warmth and hostility and placement stability (number of foster-home moves and discharge from care) as reported by 3 informants (biological parent, foster parent, and classroom teacher) after considering maltreatment risks (child age, gender, sibling ADHD, and comorbidity) and use of ADHD medication.

METHODS

We studied 252 maltreated children in 95 families during 4 yearly waves, beginning shortly after placement; children were assessed whether they remained in or were discharged from foster care.

RESULTS

Average level of inattention declined according to the biological parent, whereas hyperactivity/impulsivity symptoms declined according to both biological and foster parents. Higher inattention was associated with lower parental warmth (foster parent), higher parental hostility (biological, foster, and teacher), and discharge from care (biological parent). Higher hyperactivity was also associated with lower parental warmth (foster parent) and higher parental hostility (biological and foster parent), higher (average) number of foster-home moves, and discharge from care (biological report). Higher teacher-derived hyperactivity symptoms were associated with a history of child abuse (versus neglect); however, abused children showed a steeper decline of hyperactivity over time than those with neglect histories. Unexpected interactions were found for the impact over time of parental (foster) warmth and number of foster-home moves.

CONCLUSION

Findings point to the clinical usefulness of attending to the parenting quality and placement stability as malleable factors affecting symptom reduction subsequent to placement.

ADHD and the rise in stimulant use among children

Attention-deficit/hyperactivity disorder (ADHD) holds the distinction of being the most extensively studied pediatric mental disorder and one of the most controversial, in part because it is also the most commonly diagnosed mental disorder among minors. Currently, almost 8% of youth aged 4 to 17 years have a diagnosis of ADHD, and approximately 4.5% both have the diagnosis and are using a stimulant (methylphenidate or amphetamine) as treatment for the disorder. Yet a diagnosis of ADHD is not simply a private medical finding; it carries with it a host of policy ramifications. The enduring controversy over ADHD in the public arena therefore reflects the discomfort over what happens when science is translated into policies and rules that govern how children will be treated medically, educationally, and legally. This article (1) summarizes the existing knowledge of ADHD, (2) provides the relevant history and trends, (3) explains the controversy, (4) discusses what is and is not unique about ADHD and stimulant pharmacotherapy, (5) outlines future directions of research, and (6) concludes with a brief analysis of how two North Carolina counties have established community protocols that have improved the screening, treatment, and societal consensus over ADHD and stimulants.

Epidemiologic considerations in attention deficit hyperactivity disorder: a review and update

Epidemiologic data on attention deficit hyperactivity disorder (ADHD) are essential for planning health services and implementing strategies of detection and early intervention, with possible substantial benefits on public health. This article addresses methodological aspects of prevalence studies, recent findings on the prevalence of ADHD in childhood and adolescence based on a systematic review, current findings on the persistence of the disorder over time and prevalence in adulthood, and factors associated with ADHD. Evidence from the reviewed literature indicates the importance of methodological aspects in the understanding of epidemiologic findings and the necessity of large-scale cross-national studies. Moreover, governments clearly must direct attention to childhood mental disorders to guarantee a healthy future for their countries.

The shifting subtypes of ADHD: classification depends on how symptom reports are combined

Research on the correlates of ADHD subtypes has yielded inconsistent findings, perhaps because the procedures used to define subtypes vary across studies. We examined this possibility by investigating whether the ADHD subtype distribution in a community sample was sensitive to different methods for combining informant data. We conducted a study to screen all children in grades 1-5 (N = 7847) in a North Carolina County for ADHD. Teachers completed a DSM-IV behavior rating scale and parents completed a structured telephone interview. We found substantial differences in the distribution of ADHD subtypes depending on whether one or both sources were used to define the subtypes. When parent and teacher data were combined, the procedures used substantially influenced subtype distribution. We conclude the ADHD subtype distribution is sensitive to how symptom information is combined and that standardization of the subtyping process is required to advance our understanding of the correlates of different ADHD subtypes.

The impact of impairment criteria on rates of ADHD diagnoses in preschoolers

Behaviors characteristic of ADHD are common among preschool children, and as such, their clinical significance is oftentimes difficult to ascertain. Thus a focus on impairment is essential in determining the clinical significance of these behaviors. In order to explore the impact of impairment criteria on rates of diagnoses in inattentive/hyperactive children aged 36 through 60-months-old, we first developed, and psychometrically evaluated, the Children's Problem Checklist (CPC) which was designed to assess psychosocial impairment associated with ADHD in a community sample of preschoolers (n = 394), and found its reliability and validity to be acceptable. We then examined the impact of the inclusion of various CPC-determined impairment criteria, over and above symptom criteria measured by the ADHD-RS-IV, using various cut points ranging from the 75th to 90th percentile of our community sample. This reduced the number of children meeting criteria for ADHD by 46-77%. These findings are discussed in terms of the importance of using impairment criteria, rather than just severity of inattention, impulsivity and hyperactivity, when diagnosing ADHD in preschool children.

Nature of anxiety comorbid with attention deficit hyperactivity disorder in children from a pediatric primary care setting

The clinical characteristics of children with comorbid anxiety and attention deficit hyperactivity disorder (ADHD were examined. A sample of children from a pediatric primary care practice was assessed for anxiety disorders and ADHD. We defined four groups of children: (1) anxiety disorders only with no ADHD (n=54); (2) ADHD-only with no anxiety disorder (n=15); (3) neither ADHD nor an anxiety disorder (n=107); and (4) comorbid ADHD and anxiety disorder (n=14). Approximately 50% of children with ADHD had a comorbid anxiety disorder, and approximately 20% of children with an anxiety disorder had comorbid ADHD. The presence of comorbid ADHD and anxiety was associated with more attentional problems, school fears, and mood disorders and lower levels of social competence compared to children who had either ADHD-only or anxiety-only. Children with comorbid anxiety disorders and ADHD have more severe symptoms and are more impaired than children with either condition alone. Interventions need to be tailored to address the complexity of these comorbid conditions and their associated sequelae.

Prevalência do transtorno do déficit de atenção e hiperatividade e suas comorbidades em uma amostra de escolares

O transtorno do déficit de atenção e hiperatividade (TDAH) é comum em crianças na idade escolar e freqüentemente apresenta-se em comorbidade com outros distúrbios psiquiátricos. No Brasil, há escassez de estudos em amostras não-clínicas. OBJETIVO: Calcular a prevalência deste transtorno e suas comorbidades numa amostra de escolares. MÉTODO: Estudo observacional analítico seccional realizado numa amostra de escolares do Colégio de Aplicação da Universidade Federal do Rio de Janeiro. Utilizou-se questionário de triagem seguido por entrevista clínica estruturada com os pais de crianças suspeitas de serem portadores do transtorno. RESULTADOS: A prevalência encontrada para o TDAH foi 8,6%. As comorbidades deste transtorno se mostraram presentes em 58% dos casos, sendo transtorno opositivo-desafiador, encontrado em 38,5% dos casos, o mais prevalente. CONCLUSÃO: A prevalência do TDAH e suas comorbidades na amostra estudada é semelhante àquela observada na literatura internacional.

Evaluating the evidence for and against the overdiagnosis of ADHD

OBJECTIVE

According to the DSM-IV TR, approximately 3 to 7% of school-age children meet the criteria for ADHD. However, there is a common conception that ADHD is overdiagnosed. The purpose of this article is to evaluate the evidence for and against overdiagnosis.

METHOD

Recent prevalence studies and research on factors affecting diagnostic accuracy were reviewed. For ADHD to be overdiagnosed, the rate of false positives (i.e., children inappropriately diagnosed with ADHD) must substantially exceed the number of false negatives (children with ADHD who are not identified or diagnosed).

RESULTS AND CONCLUSION

Based on the review of prevalence studies and research on the diagnostic process, there does not appear to be sufficient justification for the conclusion that ADHD is systematically overdiagnosed. Yet, this conclusion is generally not reflected in public perceptions or media coverage of ADHD. Potential explanations for the persistence of the belief in the overdiagnosis of ADHD are offered.

Environmental influences that affect attention deficit/hyperactivity disorder: study of a genetic isolate

Three independent complex segregation analyses found that the cause of Attention Deficit/Hyperactivity Disorder (ADHD) was the presence of major genes interacting with environmental influences. In order to identify potential environmental risk factors for ADHD in the Paisa community--a very well described, genetically isolated group--we randomly selected a sample of 486 children between 6 and 11 years of age. This group included 200 children with ADHD (149 males and 51 females) and 286 healthy controls (135 males and 151 females). The ADHD DSM-IV diagnosis was obtained using the DICA and BASC evaluation instruments, and the children's mothers or grandmothers filled out a questionnaire on each child's exposure to prenatal, neonatal, and early childhood risk factors. The data were analyzed using cross tabulation and stepwise logistic multiple-regression analyses. Cross tabulation associated ADHD with a variety of factors, including miscarriage symptoms, premature delivery symptoms, maternal respiratory viral infection, moderate to severe physical illness in the mother during gestation, prenatal cigarette and alcohol exposure, neonatal seizures, asphyxia or anoxia, severe neonatal illness, mild speech retardation, moderate brain injury, and febrile seizures (odds ratio >or= 2, P < 0.05). Stepwise logistic multiple-regression analysis also uncovered a block of variables, including male gender, maternal illnesses, prenatal alcohol exposure, mild speech retardation, febrile seizures, and moderate brain injury (odds ratio >or= 2.0, P < 0.05). Future studies on the risk of developing ADHD must include these environmental factors as covariates.

Chronic administration of methylphenidate produces neurophysiological and behavioral sensitization

The electrophysiological properties of acute and chronic methylphenidate (MPD) on neurons of the prefrontal cortex (PFC) and caudate nucleus (CN) have not been studied in awake, freely behaving animals. The present study was designed to investigate the dose-response effects of MPD on sensory evoked potentials recorded from the PFC and CN in freely behaving rats previously implanted with permanent electrodes, as well as their behavioral (locomotor) activities. On experimental day 1, locomotor behavior of rats was recorded for 2 h post-saline injection, and sensory evoked field potentials were recorded before and after saline and 0.6, 2.5, and 10 mg/kg, i.p., MPD administration. Animals were injected for the next five days with daily 2.5 mg/kg MPD to elicit behavioral sensitization. Locomotor recording was resumed on experimental days 2 and 6 after the MPD maintenance dose followed by 3 days of washout. On experimental day 10, rats were connected again to the electrophysiological recording system and rechallenged with saline and the identical MPD doses as on experimental day 1. On experimental day 11, rat's locomotor recording was resumed before and after 2.5 mg/kg MPD administration. Behavioral results showed that repeated administration of MPD induced behavioral sensitization. Challenge doses (0.6, 2.5, and 10.0 mg/kg) of MPD on experimental day 1 elicited dose-response attenuation in the response amplitude of the average sensory evoked field potential components recorded from the PFC and CN. Chronic MPD administration resulted in attenuation of the PFC's baseline recorded on experimental day 10, while the same treatment did not modulate the baseline recorded from the CN. Treatment of MPD on experimental day 10 resulted in further decrease of the average sensory evoked response compared to that obtained on experimental day 1. This observation of further decrease in the electrophysiological responses after chronic administration of MPD suggests that the sensory evoked responses on experimental day 10 represent neurophysiological sensitization. Moreover, two different response patterns were obtained from PFC and CN following chronic methylphenidate administration. In PFC, the baseline and effect of methylphenidate expressed electrophysiological sensitization on experimental day 10, while recording from CN did not exhibit any electrophysiological sensitization.

Birth weight and attention-deficit/hyperactivity symptoms in childhood and early adolescence: a prospective Swedish twin study

OBJECTIVE

To determine whether low birth weight increases the risk of attention-deficit/hyperactivity disorder (ADHD) in childhood and early adolescence.

METHOD

In a population-based sample of 1,480 twin pairs born in the period 1985-1986 ascertained from the Swedish Twin Registry, birth weight was collected prospectively through the Medical Birth Registry. ADHD symptoms were measured with a 14-item checklist covering DSM-III-R criteria (parental rating) at age 8 to 9 years and 13 to 14 years. We used both a dichotomous approach for birth weight (>400 g or 15% weight difference) and ADHD (eight or more symptoms) and continuous measures to investigate between- and within-twin pair effects.

RESULTS

Our results showed that low birth weight was a risk factor for symptoms of ADHD and the associations did not diminish when we controlled for genetic influence. The lighter twin in birth weight-discordant pairs had on average 13% higher ADHD symptom score at age 8 to 9 years (p = .006) and 12% higher ADHD score at age 13 to 14 years (p = .018) compared with the heavier twin. The genetic correlations suggest modest or no genetic overlap between birth weight and ADHD.

CONCLUSIONS

The hypothesis that low birth weight is associated with the development of ADHD symptoms was supported in this prospective twin study. Fetal growth restriction seems to represent a modest but fairly consistent environmental influence on the development of ADHD symptoms.

Variations in prevalence of attention deficit hyperactivity disorder worldwide

Attention deficit hyperactivity disorder (ADHD) is among the most common, intensely investigated, and yet diagnostically controversial neurobehavioral conditions of childhood. The prevalence of ADHD has been reported with great variations among different studies, ranging from 2.2% to 17.8%. The aim of this review was to investigate the variables that influence the prevalence of ADHD and to derive a best estimate for the prevalence of the disorder. We reviewed all the 39 studies on ADHD prevalence appearing in the Pubmed and published since 1992. These studies indicate that ADHD is more common in boys than girls, in younger than older children and adolescents, in one-setting rather than two-setting screening studies, in studies based on DSM-IV rather than DSM-III-R criteria. Additional factors that may well influence prevalence rates include source of information and assessment of clinical impairment. In conclusion, our findings suggest that population characteristics, methodology features, ethnic and cultural differences and diagnostic criteria involved in studies affect the prevalence of ADHD. Standardized designs may lead to firm conclusions on the true prevalence of ADHD, the estimation of which seems impossible to be achieved by reviewing the already existing literature.

Animal models concerning the role of dopamine in attention-deficit hyperactivity disorder

Several models of attention-deficit hyperactivity disorder (ADHD) have been proposed, ranging from administration of neurotoxins to genetically manipulated models. These models are used to gain insight into ADHD as a disorder and assist in the discovery of new therapeutic strategies. However, the information gained from these models differs, depending to a large extent on the validity (or otherwise) of the model. Thus the insights gained from these models with respect to the pathophysiology and aetiology of ADHD remains inconclusive. No animal model resembles the clinical situation of ADHD perfectly but good animal models of ADHD should mimic its characteristics, confirm to an underlying theory of ADHD and ultimately make predictions of future therapies. While the involvement of dopamine (DA) in ADHD has been established, the evaluation of rodent models of ADHD particularly with respect to dopaminergic systems is attempted here. It is concluded that the neonatal 6-hydroxy-dopamine lesioned rat and DA transporter knockout/knockdown mice have the highest degree of validity for ADHD.

The prevalence of ADHD among primary school children in an Arabian society

OBJECTIVE

The aim of this study is to identify Attention Deficit Hyperactivity Disorders among primary school children in the State of Qatar.

METHOD

A cross-sectional descriptive study is conducted from March 2004 to February 2005. A total of 2,000 primary school students, ages 6 to 12, are selected, and 1,541 students (77.1%) give consent to participate in this study. An Arabic questionnaire is used to collect the sociodemographic variables and a standardized Arabic version of the Conners' Classroom Rating Scale for ADHD symptoms. Of the students surveyed, 51.7% are males and 48.3% females.

RESULTS

The data reveal that 112 boys (14.1%) and 33 girls (4.4%) scored above the cutoff for ADHD symptoms, thus giving an overall prevalence of 9.4%. Children who have a higher score for ADHD symptoms have school performance poorer than those with lower scores (p = .003).

CONCLUSION

The study reveals that ADHD is found to be a common problem among school children in Qatar.

ADHD and the dopamine transporter: are there reasons to pay attention?

The catecholamine dopamine (DA) plays an important role as a neurotransmitter in the brain in circuits linked to motor function, reward, and cognition. The presynaptic DA transporter (DAT) inactivates DA following release and provides a route for non-exocytotic DA release (efflux) triggered by amphetamines. The synaptic role of DATs first established through antagonist studies and more recently validated through mouse gene-knockout experiments, raises questions as to whether altered DAT structure or regulation support clinical disorders linked to compromised DA signaling, including drug abuse, schizophrenia, and attention deficit hyperactivity disorder (ADHD). As ADHD appears to have highly heritable components and the most commonly prescribed therapeutics for ADHD target DAT, studies ranging from brain imaging to genomic and genetic analyses have begun to probe the DAT gene and its protein for possible contributions to the disorder and/or its treatment. In this review, after a brief overview of ADHD prevalence and diagnostic criteria, we examine the rationale and experimental findings surrounding a role for human DAT in ADHD. Based on the available evidence from our lab and labs of workers in the field, we suggest that although a common variant within the human DAT (hDAT) gene (SLC6A3) is unlikely to play a major role in the ADHD, contributions of hDAT to risk maybe most evident in phenotypic subgroups. The in vitro and in vivo validation of functional variants, pursued for contributions to endophenotypes in a within family approach, may help elucidate DAT and DA contributions to ADHD and its treatment.

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.

Attention deficit and learning disabilities (ADHD/LD) among high school pupils in Holon (Israel)

Five hundred forty-three students participated in the study. The prevalence of ADHD according to criteria of DSM-4 among them was 15.2%, including three subgroups: ADHD (inattentive)- 9.7%, combined- 4.5%, and ADHD-hyperactivity-impulsivity (HI)- 1%. The prevalence of learning disability (LD) was 17.6%. The gender ratio in both groups (ADHD and LD) was equal. These pupils had lower academic achievements with lower marks. The prevalence of ADHD/LD found in the present study in Israel is in a higher range of those reported in the literature. We should remember that ADHD/LD is a neuro-behavioral disability and these children and adolescents need an early educational correcting program at home and at school.

Stimulant dosage and age, race, and insurance type in a sample of children with attention-deficit/hyperactivity disorder

OBJECTIVE

The aim of this study was to examine the association of age, race, insurance, and other factors with the prescription of stimulant medications.

METHODS

A retrospective chart review was conducted on 242 subjects, 4.8-19.8 years of age, treated in an urban referral center with a stable dose of stimulant medication for at least 6 months. Subjects were predominantly male (74.8%), African-American (52.9%), and insured by Medicaid (71.0%). The effects of age, race, insurance, gender, cognitive level, additional psychopharmacologic medications, and other factors on prescribed total daily dose (mg/day) and dose by weight (mg/kg/dose) were examined.

RESULTS

Race and insurance type together were associated with specific patterns of stimulant dosage, with higher dosing seen in Medicaid-insured non-African-American children and in privately insured African-American children. Total daily dose increased with age; however, there was an inverse relationship between age and dose by weight. There were no significant associations of gender, cognitive level, use of additional psychopharmacological medications, or other factors with total daily dose or dose by weight.

CONCLUSIONS

The sociocultural factors of race and insurance type were related to dosing of stimulant medications in children. Total daily doses increased with age, while younger children were treated with higher weight-based doses. Attention to these factors should be given in the titration of stimulant medications in the treatment of ADHD. Other factors, including gender, had no specific association.

Do child psychiatrists in Germany diagnose bipolar disorders in children and adolescents? Results from a survey

OBJECTIVES

There is a controversy about the prevalence of childhood bipolar disorders (BD). Based on discrepant results, we studied if German psychiatrists in outpatient settings diagnose BD in children and adolescents at all, and if there are possible correlates of the diagnoses of pediatric BD. We also asked how often typical manic symptoms (e.g. elated mood) are actually seen in attention deficit hyperactivity disorder (ADHD) patients.

METHODS

Provided by the medical register we had a complete list of all 251 psychiatrists in the area. Using a questionnaire we asked if and how often they diagnose BD among children and adolescents and how often they observe manic-like symptoms in children with ADHD (response rate 61%).

RESULTS

While 63% of all psychiatrists have diagnosed BD in adolescents, only 7.8% did so in children. Age and therapeutic approach of the psychiatrists were associated with the likelihood of having diagnosed BD in children. Furthermore some typical bipolar symptoms were also present in ADHD patients.

CONCLUSIONS

Our study only relied on self-reports of the psychiatrists about the diagnoses and number of cases, but BD in children seems to be rarely diagnosed in outpatient settings in Germany. The design of our study, however, cannot resolve the questions what the reasons are for this low rate of BD diagnoses, e.g. misdiagnoses, overlooking comorbidity or referral strategies. Epidemiological studies are needed and should consider multiple follow-ups.

Attention deficit/hyperactivity disorder (ADHD): complex phenotype, simple genotype?

Complex genetic traits refer to those phenotypes not fitting patterns of Mendelian segregation and/or assortment but exhibiting a preferential familial clustering that cannot be explained by cultural or environmental causes. Attention-deficit/hyperactivity disorder (ADHD) is the most common neurodevelopmental disorder of childhood and probably the most controversial. ADHD has been considered a complex genetic trait based upon the absence of a clear-cut boundary between affected and unaffected status. Furthermore, its high comorbidity with other disorders strongly suggests complex epistatic or pleiotropic effects acting in common with the environmental influences. This implies that the same gene or genes is or are associated with different and concurrently occurring phenotypes. In this study, we will review clinical and epidemiological aspects related to the ADHD phenotype, which are considered either as categorical or continuous traits. We also will discuss genetic models underlying the complexity of this behavioral phenotype and the probable role of epistatic interactions between major genes contributing to the ADHD phenotype.

Design and rationale of controlled study of long-term methylphenidate and multimodal psychosocial treatment in children with ADHD

OBJECTIVE

To describe the rationale, methodology, and sample characteristics of a dual-site treatment study (New York and Montreal) of children with attention-deficit/hyperactivity disorder (ADHD) conducted between 1990 and 1995. The hypotheses were that (1) methylphenidate combined with comprehensive multimodal psychosocial treatment was superior to methylphenidate alone in improving multiple functions and (2) the efficacy of the psychosocial intervention resulted from its specific components and not from nonspecific treatment effects.

METHOD

One hundred three children with ADHD (ages 7-9), free of conduct and learning disorders, who responded to methylphenidate, were randomized for 2 years to (1) methylphenidate treatment alone; (2) methylphenidate combined with multimodal psychosocial treatment that included parent training and counseling, academic assistance, psychotherapy, and social skills training; or (3) methylphenidate plus attention control treatment that excluded specific aspects of the psychosocial intervention. Children were switched to single-blind placebo after 12 months; methylphenidate was reinstituted when clinically indicated. Assessments included ratings by parents, teachers, children, and psychiatrists; school observations in academic and gym classes; and academic performance tests. Almost 80% of families completed the 2-year study. Companion papers present treatment effects.

CONCLUSIONS

A comprehensive 2-year psychosocial treatment was delivered successfully to children with ADHD and their families.

Assessing the impact of parent and teacher agreement on diagnosing attention-deficit hyperactivity disorder

This study examines the impact of interrater reliability on the diagnosis of attention-deficit hyperactivity disorder (ADHD). A screening of 6171 elementary school children identified 1573 children with a high risk for ADHD according to teacher rating. Follow-up parent interviews and information from teachers were collected on 243 children. Before screening, health care professionals had diagnosed ADHD in 40% of the identified children. There was low agreement between the parent and teacher reports of ADHD symptoms according to DSM-IV-based questionnaires: Inattentive (r =.34, kappa = 0.27), Hyperactive/Impulsive (r =.27, kappa = 0.22), and Performance Impairment (r =.31, kappa = 0.07). When the two-setting requirement was strictly enforced, poor interrater agreement decreased diagnostic rates for all three types of ADHD in this clinical sample: Inattentive (15%-5%), Hyperactive/Impulsive (11%-3%), and Combined (23%-7%). Parent and teacher agreement was low concerning ADHD symptoms and performance. The recommendation of multiple informants significantly decreased the prevalence. Allowing for observer disagreement by using more lenient core symptom scores could reduce the effect.

A 90-day oral gavage toxicity study of d-methylphenidate and d,l-methylphenidate in beagle dogs

d-Methylphenidate (d-MPH) was approved as a treatment for attention deficit hyperactivity disorder (ADHD) in children. The repeated-dose toxicity of the d enantiomer of d,l-methylphenidate (d,l-MPH) was assessed in male and female Beagle dogs. Dogs were orally dosed twice a day in equally divided doses 6 hours apart for total daily doses of 1, 3, and 10 mg/kg/day d-MPH or 20 mg/kg/day d,l-MPH for 90 days, followed by a 30-day recovery period. The top d-MPH dose of 10 mg/kg was equimolar to 20 mg/kg d,l-MPH in d-MPH content. The 10-mg/kg d-MPH and d,l-MPH doses were at least 13 times the maximum therapeutic dose giving rise to systemic exposures that were equivalent to or at least 2 times greater than those at the maximum therapeutic doses in children. The 10-mg/kg d-MPH and 20-mg/kg d,l-MPH doses had systemic exposures that were equivalent to or two to five times greater than the maximum therapeutic plasma levels in children respectively. There was no treatment-related mortality in all doses tested. Reversible salivation, hyperactivity, and diarrhea were seen in the high-dose d-MPH and d,l-MPH groups. Significant body weight loss and reduction in food consumption were observed in males for both high-dose groups with weights comparable to control values by the end of the recovery period. There were no abnormal clinical pathology or macroscopic or microscopic findings. Based on body weight changes, the no-observed-adverse-effect level (NOAEL) of d-MPH in beagle dogs was 3 mg/kg/day.

Neurobehavioral effects of racemic threo-methylphenidate and its D and L enantiomers in rats

D,L-methylphenidate (Ritalin) is used to treat attention deficit hyperactivity disorder (ADHD) in children. The therapeutic effect is predominantly due to the d enantiomer. Dexmethylphenidate (D-MPH; Focalin) was therefore developed for its better therapeutic index. The present study determined and compared the acute behavioral toxicity of D,L-MPH, D-MPH and L-MPH in rats after oral dosing. Comprehensive functional observational battery (FOB) evaluations and rota-rod tests were performed 30, 60 and 120 min after dosing. Ten rats/sex/dose were administered a single dose of vehicle, 2, 20, 100 mg/kg D,L-MPH and 1, 10, 50 mg/kg D-MPH or 1, 100, 500 mg/kg L-MPH. There was no mortality. Certain FOB evaluations were statistically significant from vehicle control at any of the time points with most occurring at 60 and 120 min in the high D,L-MPH dose. These included increases in rearing, difficulty in removal from box, arousal, click, tail-pinch and decreases in hind-limb splay distance, hind-limb grip strength and handling reactivity. Behavioral responses were also present at the mid-dose D,L-MPH and high dose D- and L-MPH. Responses in female were significantly different from males in D,L- and L-MPH groups suggesting a sex difference in sensitivity. In the rota-rod test, mean latency to remain on the rod was significantly less for males compared to control given high dose D-MPH and D,L-MPH. In females, latency times were significantly less for high doses of all three compounds. In summary, fewer significant FOBs were seen with D- and L-MPH compared to equimolar doses of D,L-MPH. L-MPH was the least potent in producing FOBs. These results were supported by rota-rod studies.

Economic implications of attention-deficit hyperactivity disorder for healthcare systems

Attention-deficit hyperactivity disorder (ADHD) is one of the most common chronic conditions of childhood, with adverse consequences that persist through adolescence into adulthood. Thus, the burden of illness associated with ADHD is high for affected individuals, their families, and society at large. This article reviews available information about ADHD-associated utilisation of healthcare resources, direct medical costs, and the costs or cost effectiveness of pharmacological interventions. Published estimates suggest that direct medical costs for youth with ADHD are approximately double those for youth without ADHD. Cross-sectional studies suggest that ADHD-associated incremental costs are highest for mental health services and pharmaceutical costs, and are greatest for youth with comorbid psychiatric conditions and for those being treated with stimulant medication. To guide relevant clinical and health policy, additional research is warranted on the following: source of increased costs observed among persons with ADHD; patient characteristics of those accruing high medical costs; and the long-term effect of ADHD treatment on direct and indirect costs.

A 90-day oral gavage toxicity study of D-methylphenidate and D,L-methylphenidate in Sprague-Dawley rats

D-methylphenidate is an enantiomer of D,L-methylphenidate and was developed as an improved treatment for attention deficit hyperactivity disorder in children. The current study was performed to determine and compare the toxicity of 2-50 mg/kg per day D-MPH and 100 mg/kg per day D,L-MPH for 90 days in rats with the top D-MPH dose being equimolar to 100 mg/kg D,L-MPH. The top D-MPH and D,L-MPH doses were at least 67 times that of the human dose and produced systemic exposures that were over 10 times higher than those typically achieved in children. During the course of the study, one male each from the 50 mg/kg per day and D,L-MPH groups and one female from the 50 mg/kg group died. Incidences of material around nose/eyes, scabbing, foot swelling, alopecia and abrasions were evident at 50 mg/kg per day D-MPH and 100 mg/kg per day D,L-MPH doses. Body weight and its changes decreased in a dose-dependent manner for D-MPH males. There were significant changes in some clinical chemistry measurements at the terminal bleed in the high dose groups of both sexes although most of these changes were resolved by the recovery bleed. Differences in absolute and relative body and certain organ weights for high dose D-MPH and D,L-MPH groups were seen at terminal necropsy with the differences no longer present after the recovery period. No abnormal or gross histopathological changes were associated with any of these organ weight changes reported for the terminal and recovery periods. Based on body weight changes, the no observed adverse effect level for D-MPH in rats was 20 mg/kg. Overall, the toxicity profile observed in rats with 50 mg/kg per day D-MPH was comparable to that of an equimolar dose of D,L-MPH (100 mg/kg per day) when given repeatedly for 90 days using a twice a day dosing regimen.