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PubMed2003

Attention deficit hyperactivity disorder.

OBJECTIVE: To identify ADHD children, to show the prevalence of the disorder in the age group of 5-12 years and to study their socio-demographic variables, associated medical and co-morbid psychological problems. METHODS: This is a cross-sectional case study of ADHD children presenting to a child guidance clinic in a busy pediatric hospital over a one year period. The diagnosis of ADHD was based on DSM IV criteria. RESULTS: Of the 238 children referred, 37 were diagnosed as ADHD. 64.9% of the referrals were from pediatricians. The prevalence of ADHD in pediatric clinic was 15.5%, the inattention subtype was predominant. The mean age of boys and girls with ADHD was 8.49 years and 6.82 years respectively. The male to female ratio was 6.4:1. Majority of patients were from middle socio-economic status belonging to Hindu families. 27.0% of children had developmental problems. Oppositional defiant disorder was the most prevalent while depression was the least prevalent co morbid problem. CONCLUSION: ADHD is prevalent in India and the bunch of these children are mostly presenting to the pediatrician. They need to be aware of the profile of this disorder for early detection and intervention.

Age Distribution↗

PubMed1992

A twin study of the etiology of comorbidity: attention-deficit hyperactivity disorder and dyslexia.

Monozygotic and dizygotic twin pairs, in which at least one member of each pair is reading disabled (RD), were assessed for attention-deficit hyperactivity disorder (ADHD). Within pair cross-concordances of the RD and ADHD qualitative diagnoses for monozygotic twins were larger than for dizygotic twins, although not significantly so (p less than 0.10). Thus, the data suggest that RD and ADHD may be primarily genetically independent. However, trends in the data and subtype analyses suggest that in some cases RD and ADHD may occur together because of a shared genetic etiology and that a genetically mediated comorbid subtype may exist.

Achievement↗

PubMed2005

Clinical evaluation of subjective and objective changes in motor activity and attention in children with attention-deficit/hyperactivity disorder in a double-blind methylphenidate trial.

The aim of this study was to determine drug-dependent effects on attention and motor activity in children with attention-deficit/hyperactivity disorder (ADHD) in a double-blind methylphenidate (MPH) trial using both subjective behavior ratings and objective measures of function. In particular, we were interested in the relationship between changes of those subjective and objective measures. A total of 44 ADHD children with the combined subtype completed a randomized, double-blind, placebo-controlled, crossover trial with 2 doses of MPH (0.25; 0.5 mg/kg body weight) and placebo. In each condition, computerized attention tasks were performed, teacher-behavior ratings were obtained, and actigraph data were collected in both clinical and naturalistic settings. Trend tests revealed linear effects of MPH dose on actigraph data in the test session (p = 0.02) and at school (p = 0.001), as well as on sustained attention (p < 0.001), while inhibitory control showed a quadratic dose-response curve (p < 0.001). Multivariate regression analyses revealed that changes of both, hyperactive-impulsive symptoms (28%) and inattentive symptoms (23%) could be explained by objective changes of motor activity. Thus, for clinical practice, it should be taken into account that behavior ratings of ADHD symptoms seemed to be predominantly influenced by changes of motor activity.

Analysis of Variance↗

PubMed2002

Childhood mania, attention deficit hyperactivity disorder and conduct disorder: a critical review of diagnostic dilemmas.

OBJECTIVES: Significant debate exists on whether early onset bipolar disorder is mistakenly attributed to attention deficit hyperactivity disorder (ADHD) or conduct disorder (CD), or whether ADHD and CD are frequently misdiagnosed as mania. We review the literature on the extent to which these disorders can be reliably differentiated, and describe the diagnostic confusion that may be the result of features common to both classes of disorders. METHODS: The review focuses on research studies that have examined whether overlapping symptoms of bipolar disorder, ADHD, and CD contribute to misdiagnosis of the two classes of disorders, the prevalence of early onset bipolar disorder with comorbid ADHD or CD, and theories regarding the origins of this comorbidity. RESULTS: Reliable and accurate diagnoses can be made despite the symptom overlap of bipolar disorder with ADHD and CD. Children with bipolar disorder and ADHD may have a distinct familial subtype of bipolar disorder. Some findings suggest that manic symptoms may represent 'noise' that indicates the general severity of psychopathology in a child or adolescent. CONCLUSIONS: Further prospective studies may confirm whether early onset bipolarity can be successfully differentiated from ADHD or CD, whether all three types of disorders can be recognized in comorbid cases, or whether comorbid cases represent a distinct subtype of bipolar disorder.

Adolescent↗

PubMed2000

Family study of girls with attention deficit hyperactivity disorder.

OBJECTIVE: Because attention deficit hyperactivity disorder (ADHD) is relatively infrequent among girls, little is known about the causes of ADHD in girls. To help fill this gap in the literature, the authors assessed the familial transmission of ADHD in families ascertained through girls. METHOD: Interviewers who were blind to diagnosis administered structured psychiatric interviews to 140 girls with ADHD and their 417 first-degree relatives and to 122 girls without ADHD and their 369 first-degree relatives. RESULTS: The relatives of the ADHD girls had a significantly higher prevalence of ADHD, according to either the DSM-III-R or DSM-IV definition, than the relatives of the comparison girls. However, this did not differ from the prevalence the authors reported previously for families of boys with ADHD. Like the boys' families, the relatives of the girl probands also had significantly higher prevalences of antisocial, mood, anxiety, and substance use disorders, although the prevalence of familial antisocial disorders was lower than had been observed in the boys' families. There was no association between the DSM-IV subtypes of the probands and relatives. CONCLUSIONS: The familial transmission of ADHD and comorbid disorders generalizes to families of girls with ADHD. Neither proband gender nor subtype influences the familial transmission of ADHD.

Adolescent↗

PubMed2004

Limbic corticostriatal systems and delayed reinforcement.

Impulsive choice, one aspect of impulsivity, is characterized by an abnormally high preference for small, immediate rewards over larger delayed rewards, and can be a feature of adolescence, but also attention-deficit/hyperactivity disorder (ADHD), addiction, and other neuropsychiatric disorders. Both the serotonin and dopamine neuromodulator systems are implicated in impulsivity; manipulations of these systems affect animal models of impulsive choice, though these effects may depend on the receptor subtype and whether or not the reward is signaled. These systems project to limbic cortical and striatal structures shown to be abnormal in animal models of ADHD. Damage to the nucleus accumbens core (AcbC) causes rats to exhibit impulsive choice. These rats are also hyperactive, but are unimpaired in tests of visuospatial attention; they may therefore represent an animal model of the hyperactive-impulsive subtype of ADHD. Lesions to the anterior cingulate or medial prefrontal cortex, two afferents to the AcbC, do not induce impulsive choice, but lesions of the basolateral amygdala do, while lesions to the orbitofrontal cortex have had opposite effects in different tasks measuring impulsive choice. In theory, impulsive choice may emerge as a result of abnormal processing of the magnitude of rewards, or as a result of a deficit in the effects of delayed reinforcement. Recent evidence suggests that AcbC-lesioned rats perceive reward magnitude normally, but exhibit a selective deficit in learning instrumental responses using delayed reinforcement, suggesting that the AcbC is a reinforcement learning system that mediates the effects of delayed rewards.

Adolescent↗

PubMedDate not supplied

[Prevalence of attention deficit hyperactivity disorder in Colombian children and teenagers].

INTRODUCTION: Attention deficit hyperactivity disorder (ADHD) is the most common neurobehavioural disorder among schoolchildren. It may persist into adulthood and affect performance in the academic, social, occupational and familial spheres, and increase the use and abuse of alcohol and psychoactive substances and the risk of having an accident. Its prevalence throughout the world varies widely and further knowledge about this situation would be valuable for the development of policies in the sector of education. AIMS: The aim of this research was to determine the prevalence of ADHD and its distribution according to subtypes in schoolchildren from Sabaneta, Antioquia, Colombia, in 2001. SUBJECTS AND METHODS: The analysis involved a cross-sectional descriptive study using a representative randomised multistage sample (which was proportional to the size of the groups) of schoolchildren between 4 and 17 years old. Measurement was performed in two stages, first by application of a screening form according to DSM IV criteria, and later a structured interview, Conners' and Intelligence tests. RESULTS: Prevalence was found to be 20.4% and 15.8% if only children with an intelligence quotient of 80 or above were considered. The combined subtype was the most frequent, with 9.6%. In public schools it was 16.2%, private 15.3%, age group from 7-11 years 16.9%, 12-17 years old 14.2%, males 20.9%, females 10.1%, low 14.7%, medium 17.4% and high socioeconomic level 10.7%, with a male to female prevalence ratio of 3.88 to 1. CONCLUSIONS: Prevalence of ADHD in the school population in a municipality in the Metropolitan Area of Medellin, Colombia, is high. The most frequent subtype was the combined type, which was predominant in males, had repercussions on academic performance and low proportions of pharmacological interventions for the disorder (15%). Programmes must be developed for the detection of this problem and subsequent intervention in the school population.

Adolescent↗

PubMed2006

DCD and ADHD: a genetic study of their shared aetiology.

Previous studies have found that rates of attention deficit hyperactivity disorder (ADHD) and developmental coordination disorder (DCD) are very similar, both being approximately 7% in sample populations [Kadesjö, B., & Gillberg, C. (1999). Developmental coordination disorder in Swedish 7-year-old children. Journal of the American Academy of Child and Adolescent Psychiatry, 38, 820-828; Milberger, S., Faraone, S., Biederman, J., Testa, M., & Tsuang, M. (1996). New phenotype definition of attention deficit hyperactivity disorder in relatives for genetic analyses. American Journal of Medical Genetics, 67, 369-377]. The rate of comorbidity between the two has been found to be close to 50% [Barkley, R. (1990). Attention deficit hyperactivity disorder: A handbook for diagnosis and treatment. New York: Guilford Press]. Investigations into the comorbidity of the disorders points to a shared aetiology between them. The aim of the present investigation was to examine the extent to which the shared aetiology is due to common genetic factors to both disorders. We also investigated whether particular subtypes of each disorder were more linked than others. Mailed questionnaires were completed by parents (predominantly mothers) of 1285 twin pairs aged 5 and 16 years from the volunteer Australian Twin Registry (ATR). Included were a DSM-IV-based ADHD form, the alternative SWAN (Strengths and Weaknesses of ADHD Symptoms and Normal Behaviour scale) and the Developmental Coordination Disorder Questionnaire (DCDQ). Statistical analyses including structural equation modelling were carried out to explore the genetic factors of both disorders. The modelling showed a strong shared additive genetic component between most subtypes of ADHD and DCD to the subtypes of the other disorder. Analyses comparing the two ADHD measures showed an overlap of the symptoms captured by each measure but also significant differences. The DCD-fine motor and ADHD-Inattentive were most strongly linked using the DSM-IV based scale. On the SWAN scale the results were similar but the general coordination scale was also very strongly linked. Implications for the use of different assessment tools are discussed.

Adolescent↗

PubMed2003

ADHD treatment and academic performance: a case series.

Most new cases of attention deficit-hyperactivity disorder (ADHD) are of the predominantly inattentive subtype. Research on the use of psychostimulants in these patients has shown a high rate of nonresponders. Although psychostimulants showed a short-term decrease in symptoms in students diagnosed with predominantly inattentive ADHD, they did not significantly improve grade-point averages.

Attention↗

PubMed2000

Patterns of psychiatric comorbidity with attention-deficit/hyperactivity disorder.

Attention deficit/hyperactivity disorder (ADHD) is frequently comorbid with a variety of psychiatric disorders. These disorders include oppositional defiant (ODD) and conduct disorders (CD), and affective, anxiety, and learning disorders. Studies which have examined the comorbidity of these disorders with ADHD are reviewed. ADHD and ADHD with CD seem to be distinct subtypes; children with ADHD/CD are at higher risk of antisocial personality as adults. Coexisting anxiety may attenuate impulsivity in ADHD. Studies examining stimulant response in children with ADHD/anxiety have recently yielded conflicting results. Anxiety and ADHD seem to be inherited independently. The prevalence of major depressive disorder (MDD) and bipolar disorder among children with ADHD is controversial, but there clearly exists a subgroup of severely emotionally labile children with ADHD who present serious management issues for the clinician. About 20% to 25% of children with ADHD meet criteria for a learning disorder (LD), but LD seems to be independent of ADHD.

Attention Deficit Disorder with Hyperactivity↗

PubMed2004

Time perception: does it distinguish ADHD and RD children in a clinical sample?

This study used a double-dissociation design to evaluate whether children with ADHD demonstrated specific deficits relative to children with Reading Disorders. Recent theory suggests that ADHD children have deficits in time perception and working memory, whereas RD children have deficits in phonological decoding. The performance of 113 clinic-referred children aged 6-11 was examined using measures of working memory, phonological processing, and time perception. Respondents completed two time production tasks in which they were to judge when 30-s had elapsed, and another in which they were asked to estimate the duration of the Conners' CPT (CCPT). Time Perception and phonological processing variables were submitted to a 2 x 2 ANCOVA (ADHD vs. RD), covarying for age, SES, IQ, and working memory. Children with ADHD were more likely to overestimate the time taken for the CCPT than children without ADHD, but no group differences were found on the 30-s estimation tasks. Children with RD did not display deficits in time estimation, but showed deficits in auditory phonological processing. The lack of interaction effects supported an "etiological subtype" over the "phenocopy" model of ADHD and RD. No group differences were detected using the CCPT. Although our previous studies did not find an order effect for the Conners' CPT in a 1-hr battery, a fatigue effect was evident with a 1.5-hr battery. The implications for Barkley's behavioral inhibition theories (R. Barkley, 1997) are discussed.

Articulation Disorders↗

PubMed2000

Validity of DSM-IV subtypes of attention-deficit/hyperactivity disorder: a family study perspective.

OBJECTIVE: To test the hypothesis that the clinical severity of subtypes paralleled a gradient of familial severity. METHOD: One hundred forty children with attention-deficit/hyperactivity disorder (ADHD) and 120 normal control children and their biological relatives were studied: Because these data had been collected prior to the publication of DSM-IV, DSM-III-R symptoms were used to approximate DSM-IV subtypes using a method the authors had validated in prior work. RESULTS: The first prediction from the hypothesis was true: rates of ADHD among relatives of each subtype group were greater than rates among relatives of controls. But the second prediction did not hold: rates of ADHD were not significantly higher among relatives of combined-typed probands compared with relatives of other probands. The "gradient model" also predicted that subtypes would not "breed true" (i.e., the subtype of the relative would not be the same as that of the proband). The prediction of nonspecificity was refuted for the inattentive and combined subtypes, but hyperactive-impulsive ADHD was found almost exclusively among relatives of hyperactive-impulsive probands. CONCLUSIONS: Although the results are limited by some small subsamples along with the use of a DSM-III-R-ascertained sample, they provide little evidence for the idea that DSM-IV subtypes of ADHD correspond to familially distinct conditions. They also do not confirm the idea that the subtypes fall along a gradient of familial severity. Instead, they suggest that symptom differences among subtypes are due to nonfamilial, environmental causes.

Adolescent↗

PubMed2003

Deficient response inhibition as a cognitive endophenotype of ADHD.

OBJECTIVE: To investigate whether a deficient response inhibition is a cognitive endophenotype of attention-deficit/hyperactivity disorder (ADHD). The authors hypothesized that nonaffected siblings of ADHD probands would have a response inhibition between that of ADHD probands and normal controls, although they resembled the controls at a behavioral level. METHOD: Participants were 25 ADHD probands with a family history of ADHD, their nonaffected siblings (n = 25), and 48 normal controls matched for age and IQ. All participants were between 6 and 17 years of age. The nonaffected siblings were compared with their ADHD siblings and with controls on measures reflecting different types of response inhibition. RESULTS: The nonaffected siblings had results similar to those of the ADHD probands, who differed from the controls on all inhibition measures (p <.05). CONCLUSIONS: Siblings of ADHD probands, while not behaviorally expressing the disorder, have ADHD-associated deficits in response inhibition. This suggests that subtyping based on measures of response inhibition can help identify genetic susceptibility to ADHD. Children with a genetic vulnerability to ADHD may have hidden cognitive deficits in the absence of manifest behavioral symptoms. Therefore, they should be monitored to detect possible learning problems.

Adolescent↗

PubMed2005

Neuropsychological analyses of comorbidity between reading disability and attention deficit hyperactivity disorder: in search of the common deficit.

Measures of component reading and language skills, executive functions, and processing speed were administered to groups of children with attention deficit hyperactivity disorder (ADHD; n = 113), reading disability (RD; n = 109), both RD and ADHD (n = 64), and neither RD nor ADHD (n = 151). Groups with RD exhibited pronounced deficits on all measures of component reading and language skills, as well as significant weaknesses on measures of verbal working memory, processing speed, and response inhibition. Groups with ADHD exhibited weaknesses on all response-inhibition and processing speed tasks and were impaired on some measures of component reading skills and verbal working memory. The group with comorbid RD and ADHD exhibited the combination of the deficits in the RD-only and ADHD-only groups, providing evidence against the phenocopy and cognitive subtype hypotheses as explanations for the co-occurrence of RD and ADHD. Slow and variable processing speed was characteristic of all 3 clinical groups, suggesting that measures of this domain may be useful for future studies that search for the common genes that increase susceptibility to RD and ADHD.

Adolescent↗

PubMed2005

Attention-deficit/hyperactivity disorder (ADHD) as a risk factor for persistent nocturnal enuresis in children: a two-year follow-up study.

AIMS: A previous prevalence study indicated that the prevalence of ADHD is highly increased in enuretic children. In the current 2-y follow-up study we investigate the relationship between both disorders further. Our goal is to determine whether the ADHD diagnoses can be reconfirmed and whether children with ADHD are more at risk for difficult-to-cure enuresis. Moreover, we explore the effect of medical enuresis parameters on the course of the voiding problem. METHODS: Eighty-six children with enuresis were screened twice on the presence of ADHD with a 2-y interval. A multi-method, multi-informant assessment of ADHD was used, the child's medical file was consulted, and a parent questionnaire on the child's current voiding problems was completed. RESULTS: Although 73% of all children with a 2-y-old diagnosis of ADHD still meet the disorder's criteria, only 66% of all subtype diagnoses can be reconfirmed. The odds that a child with ADHD still has voiding problems after 2 y are 3.17 times higher than for a child without ADHD. Although a slightly increased number of prescribed therapies in the ADHD group was noticed, no other significant differences in enuresis treatment methods were found between the groups. The medical parameters were not associated with treatment outcome. CONCLUSION: Since 73% of ADHD diagnoses can be reconfirmed, the data suggest that the prevalence of the ADHD syndrome rather than reactive ADHD symptomatology is increased in enuretic children. Children with ADHD are at risk for persistent enuresis. Two-year-old medical enuresis parameters seem to have little effect on the current presence/absence of enuresis.

Analysis of Variance↗

PubMed2005

Causal heterogeneity in attention-deficit/hyperactivity disorder: do we need neuropsychologically impaired subtypes?

Before assigning full etiologic validity to a psycopathologic disorder, disease theory suggests that a causal dysfunction in a mechanism within the affect individuals must be identified. Existing theories on attention-deficit/hyperactivity disorder (ADHD) suggest such dysfunctions in cognitive, neuropsychological, or motivational processes in the child. To date, researchers have tested these theories by comparing groups with DSM-defined ADHD to children without ADHD. Using executive functioning as an illustration of an issue that exists across all such theories, this article describes substantial overlaps in the group performance data. Thus only a subgroup may have executive deficits. Noted are other supportive data suggesting multiple pathways to ADHD. The article explores implications and recommends that future theory and research give more consideration to the probability that only a subset of behaviorally defined children will have a deficit in a given neurocognitive mechanism believed to contribute to the disorder. Creation of a provisional set of criteria in DSM-V for defining an "executive deficit type" could stimulate research to validate the first etiologic subtype of ADHD and spur the development of more sophisticated causal models, which in the longer term may give clinicians ways to target and tailor treatments.

Attention Deficit Disorder with Hyperactivity↗

PubMed2004

A prospective, multicenter, open-label assessment of atomoxetine in non-North American children and adolescents with ADHD.

OBJECTIVE: The aim of this study was to study treatment response to atomoxetine in a large, multicenter study of non-North American patients with ADHD. METHODS: A total of 604 children and adolescents with ADHD were enrolled in a 10-week open-label trial with atomoxetine prior to randomization to a double-blind relapse prevention phase at 33 sites in the United Kingdom, continental Europe, Israel, South Africa, and Australia. All patients had ADHD symptom severity at least 1.5 standard deviations above United States age and gender norms for their diagnostic subtype as measured by the investigator-scored ADHD Rating Scale (ADHD RS). Outcomes were assessed by analysis of change in the ADHD RS; functional and psychosocial outcomes were assessed using the Child Health Questionnaire (CHQ). RESULTS: At endpoint, ADHD RS total scores decreased by an average of 56.7%, and 69% of patients were rated as having no or minimal symptoms. Significant improvement was observed in psychosocial and functional outcomes. Discontinuations attributed to adverse events were < 4%. CONCLUSION: These open-label data, gathered in an international setting, add to our knowledge of the value of atomoxetine in treating ADHD symptoms, as well as its safety and tolerability.

Adolescent↗

PubMed1999

Behavioral and neuropsychological correlates of hyperactivity and inattention in Brazilian school children.

Attempts at subtyping attention-deficit-hyperactivity disorder (ADHD) along the hyperactivity dimension are considered controversial. This study addresses this issue by dividing a non-clinical sample of Brazilian children (mean age, 9.4 years; SD, 2.9), who were attending a mainstream school in the Greater Rio de Janeiro area, into four behavioral domain groups (normal [NO, N=324], hyperactive/impulsive [HI, N=17], inattentive [IA, N=48], and combined [C, N=13]) on the basis of teacher ratings on an ADHD scale. The groups did not differ in intellectual level as determined by the Human Figure Drawing test. Comparisons were made between groups along the factorial dimensions extracted from the Composite Teacher Rating Scale, academic performance and neuropsychological measures were then performed. Our data showed that IA and C children are less independent and more prone to socialization problems than NO children, and that HI and C children are less anxious and fearful than IA children. Furthermore, the groups differed in academic and neuropsychological performance. The results could be considered consistent with the hypothesis that ADD with hyperactivity (ADD/+) and ADD without hyperactivity (ADD/-) represent singular nosological entities.

Achievement↗