ADHD in a school sample of Brazilian adolescents: a study of prevalence, comorbid conditions, and impairments

Smoking during pregnancy and attention-deficit/hyperactivity disorder, predominantly inattentive type: a case-control study

OBJECTIVE

Few previous studies assessed specifically attention-deficit/hyperactivity disorder, predominantly inattentive subtype (ADHD-I) in nonreferred samples. This study investigated the association between ADHD-I and prenatal exposure to nicotine.

METHOD

In a case-control study performed between September 2002 and April 2005, we assessed a nonreferred Brazilian sample of 100 children and adolescents with ADHD-I and 100 non-ADHD controls (6-18 years old). Cases and controls, matched by gender and age, were screened using teacher reports in the Swanson, Nolan, and Pelham-IV (SNAP-IV) scale. They were systematically evaluated through structured diagnostic interviews. Prenatal exposure to nicotine and potential confounding factors were evaluated by direct interview with mothers.

RESULTS

Adjusting for confounding factors (maternal ADHD, oppositional defiant disorder, birth weight, and alcohol use during pregnancy), children whose mothers smoked>or=10 cigarettes per day during pregnancy presented a significantly higher odds ratio for ADHD-I than children who were not exposed to nicotine during pregnancy (odds ratio 3.44; 95% confidence interval 1.17-10.06). Dimensional analyses showed significantly higher inattentive scores in subjects whose mothers smoked>or=10 cigarettes per day than in others after adjusting for confounding factors (p=.002).

CONCLUSIONS

In a nonreferred sample, the authors expanded to ADHD-I previous findings documenting the association between prenatal exposure to nicotine and broadly defined ADHD in clinical samples.

Hyperactivity and attention problems in a Swiss sample of school-aged children: effects of school achievement, child gender, and informants

OBJECTIVE

The sensitivity and tolerance regarding ADHD symptoms obviously differ from one culture to another and according to the informants (parents, teachers, or children). This stimulates the comparison of data across informants and countries.

METHOD

Parents and teachers of more than 1,000 school-aged Swiss children (5 to 17 years old) fill in Conners's questionnaires on ADHD. Children who are older than 10 years old also fill in a self-report questionnaire. Results are compared to data from a North American sample.

RESULTS

Swiss parents and teachers tend to report more ADHD symptoms than American parents and teachers as far as the oldest groups of children are concerned. Interactions are evidenced between school achievement, child gender, and informants. A relatively low rate of agreement between informants is found.

CONCLUSION

These results strengthen the importance to take into account all informants in the pediatric and the child psychiatry clinic, as well as in the epidemiological studies.

Lack of gender effects on subtype outcomes in adults with attention-deficit/hyperactivity disorder: support for the validity of subtypes

The aim of the present study is to verify if gender modifies the clinical, adaptative and psychological outcomes of adult attention-deficit/hyperactivity disorder (ADHD) subtypes. We evaluated 219 clinically referred adult patients. The interviews followed the DSM-IV criteria,using the K-SADS-E for ADHD and oppositional defiant disorder and SCID-IV for comorbidities. Regression models were used to analyze gender and subtype main effects and interactions in psychiatric outcomes. In the initial sample, 117 patients (53.5%) were of the combined subtype, 88 (40%) were inattentives and 14 (6.5%) hyperactives. There were no significant interactions between gender and subtype in any variable assessed. Men and women did not differ in the relative frequency of each subtype. Patients of the combined subtype in both genders presented a higher severity and increased rates of conduct and ODD disorders than inattentives. The main effects of gender and subtype in this sample are similar to those previously reported in other countries, suggesting the cross-cultural equivalence of the phenotype. The absence of significant interactions between gender and subtype suggests that, at least in clinical-based samples, DSM-IV adult ADHD subtypes present cross-gender validity.

Integrative neuroscience approach to predict ADHD stimulant response

Despite high rates of prescription, little is known about the long-term consequences of stimulant medication therapy for attention-deficit hyperactivity disorder (ADHD) sufferers. Historically, the clinical use of stimulants for ADHD has been based on trial and error before optimal therapy is reached. Concurrently, scientific research on the mechanism of action of stimulants has influenced neurobiological models of ADHD, but has not always informed their prescription. Whilst the two main stimulant types (methylphenidate and dexamphetamine) have numerous similarities, they also differ (slightly) in mechanism and possibly individual response. A further issue relates to differences in cost and availability compounded by the expectation for stimulants to be effective in ameliorating a broad spectrum of ADHD-related symptoms. Thus, there is an increasing need for treating clinicians to prescribe not only the most effective drug, but also the most appropriate dose with the associated release mechanism and schedule for each ADHD patient presented. In this regard, the field is witnessing an emergence of the personalized medicine approach to ADHD, in which treatment decisions are tailored to each individual. This shift requires a new approach to research into treatment response prediction. Given the heterogeneity of ADHD, a profile of information may be required to capture the most sensitive predictors of treatment response in individuals. These profiles will also benefit from the integration of data from clinical rating scales with more direct measures of cognition and brain function. In conclusion, there is a need to establish a more robust normative framework as the baseline for treatment, as well as diagnostic decisions, and as discussed, the growth of integrated neuroscience databases will be important in this regard.

A comparison of North American versus non-North American ADHD study populations

Few large, prospective clinical studies in Europe have assessed the validity and applicability of research methods used to study ADHD in North America. To assess comparability of study populations, we examined baseline patient characteristics from a group of North American studies against those of a large European/African/Australian study. All studies used identical diagnostic assessments and inclusion criteria, with ADHD diagnosis and the presence of comorbid psychiatric conditions confirmed using the KSADS-PL. Raters were trained and assessed to ensure uniform diagnostic and symptom severity rating standards. Six hundred and four patients (mean age = 10.2 years) enrolled in the non-North American study, and 665 patients (mean age = 10.4 years) enrolled in the North American study. The proportion of girls was higher in the North American studies (29.2% vs. 10.4%, p < 0.001). In both groups, most patients had a positive family history of ADHD and previous stimulant treatment. Fewer had the inattentive subtype of ADHD, and mean severity was slightly higher in the non-North American study. Results demonstrate that, when a uniform set of rigorous, standardized diagnostic criteria are used by skilled clinicians, the patient populations identified are generally similar. This supports the practice of generalizing results from treatment studies across geographies.

Genotypic interaction between DRD4 and DAT1 loci is a high risk factor for attention-deficit/hyperactivity disorder in Chilean families

Attention-deficit/hyperactivity disorder, ADHD [MIM 126452], is a common, highly heritable neurobiological disorder of childhood onset, characterized by hyperactivity, impulsiveness, and/or inattentiveness. As part of an ongoing study of ADHD, we carried out a family-based discordant sib-pair analysis to detect possible associations between dopamine receptor D4 (DRD4) and dopamine transporter 1 (DAT1) polymorphisms and ADHD in Chilean families. Both loci individually classified as homozygotes or heterozygotes for the DRD4 7-repeat and DAT1 10-repeat alleles, did not exhibit genotype frequency differences between affected children and their healthy siblings (Fisher's exact test P > 0.25 in both cases). However, the simultaneous presence of both DRD4 7-repeat heterozygosity and DAT1 10 allele homozygosity were significantly higher (34.6%) in cases (26), compared with their unaffected siblings (25) (4%; Fisher's exact test P = 0.0096; odds-ratio, OR = 12.71). Increased density of dopamine transporter in ADHD brains, along with abundance of 7-repeat D4 receptors in prefrontal cortex, which is impaired in ADHD patients, make the observed gene-gene interaction worthy of further incisive studies.

Transtorno do déficit de atenção e hiperatividade (TDAH): aspectos relacionados à comorbidade com distúrbios da atividade motora

A presente revisão aborda aspectos fisiopatológicos e clínicos referentes ao Transtorno do Déficit de Atenção com Hiperatividade (TDAH), em especial aqueles que concernem à associação desse transtorno com o Distúrbio do Desenvolvimento da Coordenação (DDC). Utilizou-se a base de dados Medline para levantamento de artigos indexados a partir de 1965 até 2004. Aos artigos selecionados dessa forma, outros foram obtidos pela relevância atribuída a eles nas fontes iniciais. A pré-disposição hereditária desse transtorno é indiscutível, bem como a presença da disfunção nora-drenégica e dopaminérgica no córtex pré-frontal e suas conexões. Apesar desse conhecimento, o diagnóstico da condição se baseia em dados clínicos. As associações mórbidas ocorrem em cerca de metade dos indivíduos, sendo as principais comorbidades de natureza psiquiátrica. A presença de uma comorbidade pode modificar a terapêutica e o prognóstico. O Distúrbio do Desenvolvimento da Coordenação, condição também de diagnostico clínico, confere pior prognóstico às crianças que partilham ambos os quadros. Recomenda-se que uma busca ativa de condições associadas seja realizada em cada criança diagnosticada como portadora de TDAH.

Attention and behavioural problems of Finnish adolescents may be related to the family environment

BACKGROUND

Adolescents' attention and behavioural problems in relation to the family environment were studied in the Northern Finland 1986 Birth Cohort.

METHOD

Fifteen-year-old adolescents (N=6888) completed the Youth Self-Report (YSR) questionnaire and their parents (N=6643) completed the Strengths and Weaknesses in ADHD and Normal Behaviours (SWAN) questionnaire. The ratings were compared in relation to gender and family characteristics.

RESULTS

Girls scored higher than boys on the YSR attention problems subscale (means 4.61 vs. 3.41), the rule-breaking behaviour subscale (means 4.25 vs. 3.69) and the aggressive behaviour subscale (means 7.18 vs. 5.63). Parents reported more SWAN attention problems in their sons than in their daughters. Living in an other than intact family increased YSR and SWAN attention problems and YSR behavioural problems in both genders. Adolescents living in very large families (11-19 children) had least attention and behavioural problems.

CONCLUSIONS

Attention and behavioural problems seem to be common among adolescents in Finland. For both genders, living in other than intact families increases especially behavioural problems. Additionally, a very large family seems to be a protective factor against those problems.

[Attention-deficit hyperactivity disorder comorbidity in a school sample of children]

OBJECTIVE

To evaluate the frequency of conduct disorder (CD), oppositional defiant disorder (ODD) and obsessive-compulsive disorder (OCD) in children with attention-deficit hyperactivity disorder (ADHD).

METHOD

This study was performed with children between 7 and 11 years old who fit the DSM-IV diagnostic criteria (n=35) to ADHD, normal neurologic examination and abnormal evolutionary neurological examination (ENE) by Lefèvre. Parents answered a questionnaire with DSM-IV criteria to ADHD and comorbidities.

RESULT

ADHD combined subtype was the most prevalent (51.4%). Fourteen (40%) had CD, including two with both CD and OCD. Five (14.2%) had only ODD and one (2.8%) only OCD. Eleven of fourteen children (78.5%) with CD had also ADHD combined subtype, with significant statistical difference (p<0.05). Eleven of fifteen children (73.3%) without comorbidity had inattentive or hyperactive subtype (p<0.05).

CONCLUSION

The frequency of association between CD and ADHD was high, much more in combined subtype.

Estudo piloto da prevalência do transtorno de déficit de atenção e hiperatividade entre crianças escolares na cidade do Salvador, Bahia, Brasil

O presente estudo se propõe a estimar a prevalência do transtorno de déficit de atenção e hiperatividade (TDAH) em escolares através de inquérito com professores. Foi realizado um estudo piloto baseado no total de alunos do ensino fundamental, em escolas da rede pública e privada da cidade do Salvador, BA. O instrumento diagnóstico utilizado foi a Escala de TDAH versão para professores. Oito crianças (5,3%) apresentavam alta probabilidade de ter o subtipo predominantemente desatento, três escolares (2%) apresentavam alta probabilidade de apresentar o subtipo predominantemente hiperativo/impulsivo e uma criança (0,6%) apresentava alta probabilidade de apresentar o subtipo combinado. Crianças com TDAH podem ter sérios problemas de funcionamento social. O problema não se resume aos déficits trazidos pela doença, mas à associação co-mórbida com outros transtornos, que pode resultar em comprometimento social grave. O reconhecimento precoce e o manejo adequado do TDAH pode redirecionar o desenvolvimento educacional e psicossocial dessas crianças.

Attention-deficit/hyperactivity disorder in a diverse culture: do research and clinical findings support the notion of a cultural construct for the disorder?

There is still some debate in the literature whether Attention-Deficit Disorder/Hyperactivity (ADHD) is best conceptualized as a biological disorder or if it is best understood as a cultural construct. This review aims to contribute to disentangle this issue assessing clinical and research data on ADHD in a complete diverse culture from a developing country. We performed a systematic computerized review of the literature on ADHD in Brazil. All investigations were included if dealing with ADHD prevalence, etiology, symptomatological construct, or treatment. Findings were compared to those from studies in developed countries. The prevalence rates of ADHD (5.8% using DSM-IV criteria, 1.5% using ICD-10), the bi-dimensional factor construct extracted from factor analyses (inattention and hyperactivity/impulsivity), the pattern of ADHD comorbidity in clinical samples, the family genetic data suggesting a 39% family transmission in clinical samples and the role of some potential candidate genes in dopaminergic and noradrenergic systems, as well as data on the efficacy of methylphenidate in the disorder are all very similar to findings from developed countries. Taken together, these findings suggest that ADHD is not a cultural construct, reinforcing the importance of applying similar research methodology in different cultures to make findings comparable.

Attention deficit/hyperactivity disorder and ethnicity

Despite the large volume of research dedicated to attention deficit/hyperactivity disorder (ADHD), the influence of ethnicity on the condition is still to be adequately addressed. Previous studies have shown differing rates of ADHD between different countries (although this can be affected by the assessment tool used). Cultural environment may affect a child's behaviour, but the differing attitudes of parents, clinicians, and society around the world towards acceptable behaviour may also influence diagnosis. If assessment criteria could be consistently applied across different ethnic groups, the prevalence of ADHD would probably be similar.

Brain perfusion and dopaminergic genes in boys with attention-deficit/hyperactivity disorder

Neuroimaging studies have suggested the involvement of several brain areas in attention-deficit/hyperactivity disorder (ADHD). Genetic investigations have supported the role of both dopamine D4 receptor gene (DRD4) and dopamine transporter gene (DAT1) in the vulnerability to the disorder. This study evaluates whether the presence of risk alleles at DRD4 and/or DAT1 genes is associated with differences in regional cerebral blood flow (rCBF) in a sample of ADHD boys. The rCBF was compared between ADHD patients with and without risk alleles at DRD4 (7-repeat allele) and/or at DAT1 (homozygosis for the 10-repeat allele) genes by single photon emission computed tomography (SPECT) during continuous performance test. Images were analyzed using statistical parametric mapping (SPM-99). No significant differences in rCBF were found both between ADHD boys with and without the 7-repeat allele at DRD4 locus, as well as between ADHD boys homozygous for the 10-repeat allele and ADHD subjects with other genotypes at the DAT1 locus. However, a significantly higher perfusion in the right middle temporal gyrus was found in the group with risk alleles at both DRD4 and DAT1 loci (n = 6) compared to ADHD boys without risk alleles at both loci (n = 28) (P < 0.05). Our findings suggest that a higher recruitment in middle temporal gyrus, an area associated to working memory and selective attention, should exist to compensate a putative effect of the interaction between these dopaminergic genes.

New formulations of stimulants for attention-deficit hyperactivity disorder: therapeutic potential

New formulations of stimulant medications for the treatment of attention-deficit hyperactivity disorder (ADHD) have been an important focus for pharmaceutical industry research and development over the past decade. In this article, we review and assess the therapeutic potential of five new stimulant formulations (one immediate release and four longer-acting preparations) that have recently become available for the treatment of ADHD. While the therapeutic potential of immediate-release enantiomers of methylphenidate has not yet been clinically realised, new long-acting formulations of stimulants have changed the standard of care for children, adolescents and adults with ADHD. The longer duration of action of these once-daily compounds, and the consequent expansion of the duration of daily ADHD coverage afforded by them, has introduced the realistic possibility of reducing the overall daily burden of ADHD on affected individuals. Although more expensive, these new stimulant formulations are easier for patients to use than older stimulants, more resistant to abuse and misuse, and allow for increased privacy of ADHD treatment at school or work.

Transtornos alimentares comórbidos em uma amostra clínica de adultos com transtorno do déficit de atenção com hiperatividade

A comorbidade de transtornos alimentares (TA) com o transtorno do déficit de atenção com hiperatividade (TDAH) é pouco investigada, apesar de relevante para o tratamento clínico. MÉTODOS: 86 adultos com transtorno do déficit de atenção com hipeartividade segundo o DSM-IV de uma amostra inicial de 107 indivíduos auto-referidos para um centro especializado em TDAH foram entrevistados com o SCID-P para avaliar a presença de transtornos alimentares e outros transtornos comórbidos. RESULTADOS: Nove pacientes apresentavam transtornos alimentares, sendo o transtorno da compulsão alimentar periódica (TCAP) o diagnóstico mais comum. O grupo com transtornos alimentares revelou maior número de comorbidades (p=0,02), não foram observadas, entretanto, diferenças quanto ao sexo, idade na avaliação atual, escolaridade e tipo de transtorno do déficit de atenção com hiperatividade entre os grupos. CONCLUSÃO: Amostras clínicas de transtorno do déficit de atenção com hiperatividade podem apresentar elevada prevalência de comorbidade com transtorno da compulsão alimentar periódica. Pacientes com transtorno do déficit de atenção com hiperatividade e transtornos alimentares podem apresentar um perfil diferente de comorbidades.

The distribution of symptoms of attention-deficit/hyperactivity disorder and oppositional defiant disorder in school age children in Turkey

OBJECTIVE

The aim of this study was to determine the prevalence of attention-deficit/hyperactivity disorder (ADHD) and oppositional defiant disorder (ODD) in school age children in Sivas province centre and to examine the distribution of symptoms according to subtypes.

METHOD

The study population was made up of 1425 children between the ages of 6 and 15 from eight primary schools selected by random sampling method in Sivas province centre. All students were given a questionnaire prepared according to DSMIV criteria that was completed by their parents or teachers. This form includes 18 symptoms of ADHD and eight symptoms of ODD. Student's t-test and variance analysis were used for statistical evaluation.

RESULTS

A prevalence of 8.1% was found for ADHD in our study. According to subtypes, 32.2% of these were "inattentive", 40% were "hyperactive" and 27.8% were combined type. A prevalence of 11.5% was found for ODD. The boy/girl ratio was > 1 for both ADHD and ODD, and 52.2% of those with ADHD were established as having ODD at the same time.

CONCLUSIONS

The prevalence of ADHD and ODD in primary school children was not considered to be small. Studies concerning the distribution of symptoms in different societies, cultures, and viewpoints and identification of children with this type of problem are beneficial for early diagnosis and prophylactic treatment.

Diagnostic performance of the CBCL-Attention Problem Scale as a screening measure in a sample of Brazilian children with ADHD

OBJECTIVE

To evaluate the diagnostic performance of the Attention Problem Scale of the Child Behavior Checklist (CBCL-APS) for the screening of Attention-Deficit/Hyperactivity Disorder (ADHD) in a sample of Brazilian children and adolescents.

METHODS

The CBCL-APS was given to 763 children and adolescents. Child psychiatrists using DSM-IV criteria confirmed the clinical diagnoses. Diagnostic performance was evaluated through Receiver-Operating Characteristic (ROC) curves.

RESULTS

Only moderate areas under the curve (AUC) were found for the general sample (AUC = 0.79; 95% CI = 0.76-0.82), and for the subsample of referred patients (AUC = 0.78; 95% CI = 0.74-0.82). The subsample of patients with ADHD of the combined type presented the largest AUC (AUC = 0.85; 95% CI = 0.82-0.88).

CONCLUSION

Our findings concur with previous studies of different cultures demonstrating adequate diagnostic performance of the CBCL-APS for the screening of ADHD, especially of the combined type.

The acute effect of methylphenidate in Brazilian male children and adolescents with ADHD: a randomized clinical trial

OBJECTIVE

To evaluate the acute efficacy of methylphenidate (MPH) in Brazilian male children and adolescents with ADHD.

METHOD

In a 4-day, double-blind, placebo-controlled, randomized, fix dose escalating, parallel-group trial, 36 ADHD children and adolescents were allocated to two groups: MPH (n = 19) and placebo (n = 17). Participants were evaluated pre- and posttreatment using the 10-item Conners Abbreviated Rating Scale (ABRS), the Children's Global Assessment Scale (CGAS), and a simplified version of the Continuous Performance Test (CPT).

RESULTS

The MPH group had a significantly greater decrease in ABRS scores and a significantly higher increase in CGAS scores than the placebo group (p < 0.01). The MPH group showed also a significantly higher proportion of patients with a robust improvement (decrement of at least 50% in the ABRS score after the intervention) than the placebo group (p < 0.01). The MPH effect size for the ABRS was 1.05 (95% CI = 0.73-1.37).

CONCLUSION

Our results extend the efficacy of MPH on the ADHD core symptoms extensively demonstrated in clinical trials with samples from some developed countries to a sample from a developing country where a diverse culture may modulate the clinical presentation of the disorder.

An issue of access: delivering equitable health care for newly arrived refugee children in Australia

Newly arrived refugees and asylum seekers are faced with many difficulties in accessing effective health care when settling in Australia. Cultural, language and financial constraints, lack of awareness of available services, and lack of health provider understanding of the complex health concerns of refugees can all contribute to limiting access to health care. Understanding the complexities of a new health care system under these circumstances and finding a regular health provider may be difficult. In some cases there may be a fundamental distrust of government services. The different levels of health entitlements by visa category and (for some) detention on arrival in Australia may further complicate the provision and use of health services for providers and patients. Children are particularly at risk of suboptimal health care due to the impact of these factors combined with the effect of resettlement stresses on parents' ability to care for their children. Unaccompanied and separated children, and those in detention experience additional challenges in accessing care. This article aims to increase awareness among health professionals caring for refugee children of the challenges faced by this group in accessing and receiving effective health care in Australia. Particular consideration is given to the issues of equity, rights of asylum seekers, communication and cultural sensitivities in health care provision, and addressing barriers to health care. The aim of the paper is to alert practitioners to the complex issues surrounding the delivery of health care to refugee children and provide realistic recommendations to guide practice.

The effect of methylphenidate on oppositional defiant disorder comorbid with attention deficit/hyperactivity disorder

OBJECTIVE

To assess the effect of methylphenidate on the diagnosis of oppositional-defiant disorder (ODD) comorbid with attention-deficit hyperactivity disorder (ADHD).

METHOD

We conducted an open-label study in which 10 children and adolescents with a dual diagnosis of ODD and ADHD were assessed for their ODD symptoms and treated with methylphenidate. At least one month after ADHD symptoms were under control, ODD symptoms were reevaluated with the Parent form of the Children Interview for Psychiatric Syndromes (P-ChIPS).

RESULTS

Nine of the 10 patients no longer fulfilled diagnostic criteria for ODD after they were treated with methylphenidate for ADHD.

CONCLUSION

Methylphenidate seems to be an effective treatment for ODD, as well as for ADHD itself. The implications for the treatment of patients with ODD not comorbid with ADHD needs further investigation.

Symptoms defined by parents' and teachers' ratings in attention-deficit hyperactivity disorder: changes with age

OBJECTIVE

To determine whether Child Behavior Checklist/4-18 (CBCL) and Teacher Report Form (TRF) scores of children and adolescents with a first-time diagnosis of attention-deficit hyperactivity disorder (ADHD) are different and whether there is a similar difference in normal control subjects.

METHOD

We analyzed the CBCL and TRF scores of 146 patients (124 boys and 22 girls, aged 6 to 18 years; mean age 11.0 years, SD 3.6). We analyzed the same scores for 274 age and sex-matched control subjects recruited from a nationally representative sample.

RESULTS

Subjects with ADHD had significantly higher CBCL and TRF scores than control subjects. Age was significantly correlated with scores on the CBCL and TRF subscales Social Withdrawal, Somatic Complaints, and Internalization Problems; with scores on the CBCL subscale Attention Problems; and with scores on the TRF subscale Anxiety-Depression. In the group with ADHD, age was negatively correlated with scores on the CBCL and TRF subscale Externalizing Problems and with scores on the TRF subscale Aggressive Behavior. In the control group, the only significant correlation was between age and the CBCL subscale Somatic Complaints score.

CONCLUSIONS

These results indicate that underdiagnosis of ADHD in childhood may cause the emergence of greater internalization problems in adolescence.

Child mental health in Latin America: present and future epidemiologic research

OBJECTIVE

This report reviews population studies of child and adolescent mental health carried out in Latin America over the past 15 years. Also considered is the issue of how to meet the needs of children and adolescents who may present mental health problems in Latin America, given that most of them live in poverty in economies that are underdeveloped, providing limited resources.

METHOD

Ten studies from six different countries were identified that employed some form of randomized sampling method and used standardized instruments for assessment. The authors present a summary of the main characteristics of these studies, highlighting methodological features that may account for differences in the rates obtained.

RESULTS

Overall, a similar pattern of prevalence and risk factors for mental health problems in children and adolescents in Latin American countries emerged. Moreover, rates of disorders in these children are similar to the 15 to 20% found in other countries. These findings are similar to those observed when adult mental health problems are considered. Prevention and treatment strategies are discussed and the peculiarities of the delivery of mental health services for children and adolescents are explored.

CONCLUSIONS

Future research needs to focus on understanding of resilience and formal and informal mental health delivery systems of care available in different Latin American countries. Such research has high potential for ameliorating the prevention and treatment of child and adolescent mental health problems in this region of the world.

Prevalence of child and adolescent psychiatric disorders in southeast Brazil

OBJECTIVE

To describe the prevalence of DSM-IV disorders and the pattern of comorbidity in a population-based sample of 7- to 14-year-old Brazilian schoolchildren.

METHOD

Random sampling of schools (stratified into private, public rural, and public urban) was followed by random sampling of pupils from school lists. In 2000-2001, a total of 1,251 children were assessed for DSM-IV diagnoses using the Development and Well-Being Assessment, a structured multiinformant assessment supplemented by verbatim reports reviewed by clinicians.

RESULTS

The response rate was 83%. The overall prevalence of DSM-IV disorders was 12.7% (95% confidence interval = 9.8%-15.5%), with 3.5% of children being assigned as not otherwise specified rather than operationalized diagnoses. The overall prevalence of psychiatric disorder was significantly higher than in a British study with the same measures and diagnostic procedures (12.7% versus 9.7%, p =.02).

CONCLUSIONS

Approximately one in eight schoolchildren in the study area in the southeast of Brazil have psychiatric disorders involving a level of distress or social impairment likely to warrant treatment. The gulf between need and provision is currently vast.

[Analysis of methylphenidate's efficacy using the abbreviated version Conners' questionnaire in attention deficit hyperactivity disorder]

The attention deficit/hyperactivity disorder (ADHD) is a complex diagnosis. Its installation is precocious, with chronic evolution that impacts on the subject's performance in several contexts. Three to 5% of the school aged children present this disorder. The Conners' questionnaire has been used as an instrument of epidemiological survey for ADHD children.

OBJECTIVE

This study aimed to investigate if this instrument could be an useful tool for the analysis of the methylphenidate's treatment efficacy in ADHD's children.

METHOD

Twenty-one male children were selected, with ADHD combined type, chronological ages ranging from seven to 10 years and 11 months and all were treated with methylphenidate. The Conners' questionnaire abbreviated version for parents and teachers was applied in two moments, one without medication and another between six to eight months after the beginning of the methylphenidate.

RESULTS

Results pointed to a reduction in punctuation in Conners' questionnaire in all children with ADHD concomitant to clinical improvement.

CONCLUSION

Conners' questionnaire revealed to be useful not only for diagnosis, but also as an instrument to evaluate the effectiveness of the treatment of ADHD.

'I was running away from death'- the pre-flight experiences of unaccompanied asylum seeking children in the UK

OBJECTIVE

To collect information about the pre-flight experiences of unaccompanied asylum seeking children (UASC) in the UK to increase the understanding of support needed on arrival in the UK.

METHODS

Retrospective social services case file and legal statement review and semi-structured in-depth interviews with 100 UASC.

RESULTS

Nearly half of all UASC have experienced separation from or loss of parents and/or family members (47%), and a further 41% had personally experienced or witnessed violence. Sexual violence (such as rape) was reported by 24% of African girls. Many children reported complex journeys to the UK.

CONCLUSIONS

UASC arrive in the UK with a variety of potentially traumatic experiences. Whilst research is starting to identify some of the experiences of UASC, further culturally appropriate research is needed to identify their health and social needs after arrival. Further research will help to identify the specific experiences of UASC, indicating where services should be improved to deal with their complex and diverse needs.

Polymorphisms of the Dopamine Transporter Gene

Attention deficit-hyperactivity disorder (ADHD) is a very common and heterogeneous childhood-onset psychiatric disorder, affecting between 3% and 5% of school age children worldwide. Although the neurobiology of ADHD is not completely understood, imbalances in both dopaminergic and noradrenergic systems have been implicated in the origin and persistence of core symptoms, which include inattention, hyperactivity, and impulsivity. The role of a genetic component in its etiology is strongly supported by genetic studies, and several investigations have suggested that the dopamine transporter gene (DAT1; SLC6A3 locus) may be a small-effect susceptibility gene for ADHD. Stimulant medication has a well-documented efficacy in reducing ADHD symptoms. Methylphenidate, the most prescribed stimulant, seems to act mainly by inhibiting the dopamine transporter protein and dopamine reuptake. In fact, its effect is probably related to an increase in extracellular levels of dopamine, especially in brain regions enriched in this protein (i.e. striatum). It is also important to note that dopamine transporter densities seem to be particularly elevated in the brain of ADHD patients, decreasing after treatment with methylphenidate. Altogether, these observations suggest that the dopamine transporter does play a major role in ADHD. Among the several polymorphisms already described in the SLC6A3 locus, a 40 bp variable number of tandem repeats (VNTR) polymorphism has been extensively investigated in association studies with ADHD. Although there are some negative results, the findings from these reports indicate the allele with ten copies of the 40 bp sequence (10-repeat allele) as the risk allele for ADHD. Some investigations have suggested that this polymorphism can be implicated in dopamine transporter gene expression in vitro and dopamine transporter density in vivo, even though it is located in a non-coding region of the SLC6A3 locus. Despite all these data, few studies have addressed the relationship between genetic markers (specifically the VNTR) at the SLC6A3 locus and response to methylphenidate in ADHD patients. A significant effect of the 40 bp VNTR on response to methylphenidate has been detected in most of these reports. However, the findings are inconsistent regarding both the allele (or genotype) involved and the direction of this influence (better or worse response). Thus, further investigations are required to determine if genetic variation due to the VNTR in the dopamine transporter gene is able to predict different levels of clinical response and palatability to methylphenidate in patients with ADHD, and how this information would be useful in clinical practice.

Disturbed transcallosally mediated motor inhibition in children with attention deficit hyperactivity disorder (ADHD)

OBJECTIVE

The aim of this study was to investigate mechanisms of motor-cortical excitability and inhibition which may contribute to motor hyperactivity in children with attention deficit hyperactivity disorder (ADHD).

METHODS

Using transcranial magnetic stimulation (TMS), involvement of the motor cortex and the corpus callosum was analysed in 13 children with ADHD and 13 sex- and age-matched controls. Contralateral silent period (cSP) and transcallosally mediated ipsilateral silent period (iSP) were investigated.

RESULTS

Resting motor threshold (RMT), amplitudes of motor evoked potentials (MEP) and cSP were similar in both groups whereas iSP-latencies were significantly longer (p<0.05) and their duration shorter (p<0.01) in the ADHD group. For the ADHD group iSP duration tended to increase and iSP latency to decrease with age (n.s.). Conners-Scores did neither correlate with iSP-latencies and -duration nor with children's age.

CONCLUSIONS

The shortened duration of iSP in ADHD children could be explained by an imbalance of inhibitory and excitatory drive on the neuronal network between cortex layer III-the projection site of transcallosal motor-cortical fibers-and layer V, the origin of the pyramidal tract. The longer iSP-latencies might be the result of defective myelination of fast conducting transcallosal fibers in ADHD. iSP may be a useful supplementary diagnostic tool to discriminate between ADHD and normal children.

Attention-deficit/hyperactivity disorder evaluation and diagnosis: a practical approach in office practice

Attention-deficit/hyperactivity disorder is the most common neurobehavioral disorder of childhood, with most children maintaining symptoms of ADHD as adolescents and as adults. It is among the most common chronic conditions that primary care pediatricians see. Progress in brain imaging, genetics, neuropsychology, and molecular biology of ADHD reveals complex interactions between neurologic mechanisms, genetics, and environmental influences. Core behaviors seen in children with ADHD include hyperactivity, impulsivity, and inattention. The DSM-IV standard for diagnosis emphasized the importance of documenting that these behaviors occur at school and in the home, the chronicity of symptoms, and the connection between the behaviors and impairments in educational achievement or social development. The complex nature of this disorder is indicated by the observation that children and adolescents with ADHD have associated conditions, such as learning disorders, anxiety, oppositional behaviors, and depression. The AAP practice guideline on the evaluation and diagnosis of school-aged children with ADHD provides primary care pediatricians with a scientific foundation for assessing children with behavior and learning problems. Attention to accurate documentation of behaviors, coexisting learning disorders and mental health conditions, and the development of office practices that support the diagnostic process will ensure that children receive an appropriate and comprehensive assessment.

Strengths and difficulties questionnaire (SDQ): a study of school children in Ribeirão Preto

OBJECTIVE

The objective of this study is to investigate possible child psychiatric disorders using the strengths and difficulties questionnaire (SDQ).

METHOD

SDQ is a questionnaire that screens child mental health problems, comprising a total of 25 items divided in five subscales: emotional problems, hyperactivity, relationship, conduct and pro-social behavior, with five items in each subscale. We also used the impact supplement that evaluates the impairment caused by symptoms. Out of 143 children randomly chosen from a public school of Ribeirão Preto, 107 questionnaires were correctly filled in by parents. Teachers received 114 questionnaires (regarding children with parents' consent), and 108 questionnaires were correctly filled in. As a final sample, we obtained 112 questionnaires answered by parents or teachers.

RESULTS

In the questionnaires answered by the parents, we obtained high scorings such as 30.8% for emotional symptoms, 17,7% for conduct disorders, 16.8% for hyperactivity, 14% for interpersonal relationships, 18,7% for the total scores and 10.2% for the impact supplement. Questionnaires answered by the teachers had 1.83% for emotional symptoms, 8.25% for conduct disorders, 8.25% for hyperactivity, 2.75% for interpersonal relationships, 8.25% for the total scoring and 4.58% for the impact supplement. Combining the results obtained from parents and teachers we have diagnostic hypotheses in the frequencies of 7.14% for emotional disorders, 9.82% for conduct disorders, and 12.5% for psychiatric disorder not otherwise specified and no combination was noted between parents and teachers for hyperactivity. Mean age was 8.18 years, with 63% of the children being male and 37% female.

CONCLUSION

SDQ can be useful for a preliminary screening in the investigation of possible psychiatric disorders in childhood.

Is the alpha-2A adrenergic receptor gene (ADRA2A) associated with attention-deficit/hyperactivity disorder?

Attention-Deficit/Hyperactivity Disorder (ADHD) is a complex childhood-onset psychiatric disorder characterized by marked symptoms of inattention, hyperactivity, and impulsivity. The role of genetic factors in its etiology is strongly supported by family, adoption, and twin studies. Although most of the molecular studies have investigated the dopamine D4 receptor gene (DRD4) and the dopamine transporter gene (DAT1) genes in its etiology, pharmacological and brain imaging evidences seem to indicate that genes of the adrenergic system could also be attractive for association studies. We investigated a sample of 96 Brazilian ADHD children and adolescents and their parents for the ADRA2A MspI polymorphism. Although no association with either MspI allele was observed through the haplotype relative risk (HRR) analysis, effects of the ADRA2A gene on inattention and combined (inattention + hyperactivity/impulsivity) symptom scores were detected (U = 222.5, z = 2.19, P = 0.03; and U = 208.5, z = 2.32, P = 0.02, respectively). Our results suggest that the ADRA2A gene might have a small effect on ADHD susceptibility or that this gene might modulate the severity of the disorder. They are also consistent with the noradrenergic theories of ADHD, suggesting a role for the alpha2A adrenergic receptors in the disorder.

A genomewide scan for attention-deficit/hyperactivity disorder in an extended sample: suggestive linkage on 17p11

Attention-deficit/hyperactivity disorder (ADHD [MIM 143465]) is a common, highly heritable neurobehavioral disorder of childhood onset, characterized by hyperactivity, impulsivity, and/or inattention. As part of an ongoing study of the genetic etiology of ADHD, we have performed a genomewide linkage scan in 204 nuclear families comprising 853 individuals and 270 affected sibling pairs (ASPs). Previously, we reported genomewide linkage analysis of a "first wave" of these families composed of 126 ASPs. A follow-up investigation of one region on 16p yielded significant linkage in an extended sample. The current study extends the original sample of 126 ASPs to 270 ASPs and provides linkage analyses of the entire sample, using polymorphic microsatellite markers that define an approximately 10-cM map across the genome. Maximum LOD score (MLS) analysis identified suggestive linkage for 17p11 (MLS=2.98) and four nominal regions with MLS values >1.0, including 5p13, 6q14, 11q25, and 20q13. These data, taken together with the fine mapping on 16p13, suggest two regions as highly likely to harbor risk genes for ADHD: 16p13 and 17p11. Interestingly, both regions, as well as 5p13, have been highlighted in genomewide scans for autism.

[Attention deficit/hyperactivity disorder prevalence in an inner city elementary school]

OBJECTIVE

To define the prevalence of attention deficit/hyperactivity disorder (ADHD) in a sample school-aged children from a public elementary school.

METHOD

The study population was composed of all pupils who attended the first five grades at a public state school. During the first stage, school teachers and parents filled a standardized questionnaire of 18 ADHD symptoms defined at DSM-IV. In the second stage, children who screened positive and their parents were invited for a medical visit at school. After signature of an informed consent, the following procedures were done: DSM-IV symptoms questionnaire, oriented history, physical exam and neurologic exam. ADHD diagnosis was subdivided into three types: predominantly hyperactive (H), predominantly inattentive (ADD), and mixed type ADD + H.

RESULTS

Among 403 pupils recruited in the first stage, 108 screened positive. Of these, 101 were assessed. There were 68 boys and 33 girls. Median age was 9 years (Range, 6-15 years; standard deviation, 1.99). ADHD diagnosis was defined for 69 pupils (17.1%), including 27 children (39.1%) with ADD, 26 children (37.7%) with ADD + H, and 16 children (23.2%) with H without ADD. Among children who received a diagnosis of ADHD, 45 (65.2%) were boys and 24 (34.8%) were girls (ratio 1.9:1).

CONCLUSION

ADHD prevalence in a sample of 403 school-aged children from a public elementary school was 17.1%.

[Sexual violence and its prevalence among adolescents, Brazil]

OBJECTIVE

To assess the prevalence o sexual violence among adolescents of public schools.

METHODS

Fifty-two public elementary schools of Porto Alegre, Brazil, were selected through random sampling stratified by school size. An 8th grade class was selected in each school through simple random sampling and all adolescents attending the classes who agreed to participate were included in the study. The Screening Survey of Children's Exposure to Community Violence was used to identify adolescents who were victims, witnesses or knew someone who had been a victim of sexual violence.

RESULTS

There were 1,193 adolescents included in the study, representing 10.3% of all students enrolled on 8th grade classes in the city's public schools. Twenty-seven adolescents (2.3%) reported being victims of sexual violence, 54 (4.5%) reported witnessing some episode of sexual violence and 332 (27.9%) reported knowing someone who was a victim of sexual violence.

CONCLUSIONS

Exposure to sexual violence in any of the three forms of contact was a common event among the studied adolescents. Studies focusing sexual violence as a broad social phenomenon with multiples associated factors are necessary to support preventive and treatment strategies at the community level.

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.

Aceitação e rejeição: percepção de escolares desatentos no ambiente escolar

O principal objetivo deste estudo foi identificar crianças desatentas no contexto de sala de aula e verificar como percebem e são percebidas por seus colegas nesse contexto. A amostra constituiu-se de 128 escolares provenientes de uma escola pública, com idade entre seis e nove anos. Os dados foram coletados por meio de entrevistas individuais com os sujeitos e com as professoras e foram tratados por meio das provas estatísticas que permitiram que se definissem dois grupos distintos, um em que os problemas de atenção foram identificados e outro em que isso não ocorreu. Observou-se presença de maior número de atitudes negativas em relação aos colegas e à escola no grupo de crianças com problemas de atenção; que também se caracterizou como o mais rejeitado e menos aceito pelos colegas de sala de aula, configurando seus componentes como menos populares. Esses resultados permitiram que fossem identificadas importantes variáveis interferentes no processo de aprendizagem de crianças desatentas, ampliando possibilidades de intervenção capazes de minimizar os problemas enfrentados no dia-a-dia da sala de aula.

Neuropsychological performance in DSM-IV ADHD subtypes: an exploratory study with untreated adolescents

OBJECTIVE

To explore neuropsychological performance in untreated Brazilian adolescents suffering from attention-deficit hyperactivity disorder (ADHD).

METHOD

We assessed 30 untreated adolescents with ADHD and 60 healthy control subjects, aged 12 to 16 years, using a neuropsychological battery including the Wisconsin Card-Sorting Test (WCST), the Stroop Test (ST), the Digit Span, and the Word Span.

RESULTS

We found neuropsychological differences among the DSM-IV ADHD subtypes. Adolescents with the predominantly inattentive subtype (ADHD-I) performed more poorly than did control subjects on both the Digit Span and the ST. On both the Digit Span and the WCST, adolescents with the combined subtype (ADHD-C) presented significantly more impairments than did control subjects. Adolescents with the predominantly hyperactive-impulsive type (ADHD-HI) did not differ significantly from the control subjects in any measure assessed, but had a better performance than did those with ADHD-C on both the Digit Span and the WCST. In addition, adolescents with ADHD-HI performed better on the ST than did adolescents with ADHD-I.

CONCLUSIONS

These findings suggest cognitive differences among ADHD subtypes, supporting the diagnostic distinction among them. Adolescents with ADHD-HI do not seem to have significant cognitive deficits.

Genes de suscetibilidade no transtorno de déficit de atenção e hiperatividade

O transtorno de déficit de atenção e hiperatividade (TDAH) é um dos transtornos mais comuns da infância e adolescência, afetando entre 3% a 6% das crianças em idade escolar. Essa patologia caracteriza-se por sintomas de desatenção, hiperatividade e impulsividade, apresentando ainda uma alta heterogeneidade clínica. Embora as causas precisas do TDAH não estejam esclarecidas, a influência de fatores genéticos é fortemente sugerida pelos estudos epidemiológicos, cujas evidências impulsionaram um grande número de investigações com genes candidatos. Atualmente, apesar da ênfase dada a este tópico, nenhum gene pode ser considerado necessário ou suficiente ao desenvolvimento do TDAH, e a busca de genes que influenciam este processo ainda é o foco de muitas pesquisas. O objetivo desse artigo é, portanto, sumarizar e discutir os principais resultados das pesquisas com genes candidatos no TDAH.

Estimated mental retardation and school dropout in a sample of students from state public schools in Porto Alegre, Brazil

OBJECTIVES: To assess the association between estimated Mental Retardation (MR) and school dropout in a sample of students of the third and fourth grades at state schools in Porto Alegre, the capital of the southernmost state of Brazil. METHOD: In this case - control study, students that dropped out from schools (n=44) and a control group who continued attending schools (n=44) had their intelligence quotient (IQ) determined by the vocabulary and cubes subtests of the Wescheler Intelligence Scale <FONT FACE=Symbol>¾</FONT> third edition (WISC<FONT FACE=Symbol>¾</FONT>III). Students with IQ lower than 70 were considered as potential cases of MR. Other prevalent mental disorders in this age range were assessed in both groups using the Schedule for Affective Disorders and Schizophrenia for School<FONT FACE=Symbol>¾</FONT> Age Children, Epidemiological Version (K-SADS-E). RESULTS: The prevalence of potential MR was significantly higher in the dropped out group than in the control group (p<0.001). Odds ratio for school dropout was significantly higher in the presence of MR even after controlling for potentially confounding factors (age, conduct disorder, grade repetition, family structure and income) (p<0.01). CONCLUSION: Children with IQ lower than 70 (potential MR) were at higher risk for school dropout. These children need to be identified at school and specific educational strategies should be implemented to assure their inclusion in the learning process.

Comparison of male adolescent-report of attention-deficit/hyperactivity disorder (ADHD) symptoms across two cultures using latent class and principal components analysis

BACKGROUND

The goal of this study is to gauge the consistency of Attention Deficit/Hyperactivity Disorder (ADHD) latent class models that are generated by different informants such as adolescents and parents. The consistency of adolescent-derived latent classes from two different samples was assessed and these results were then compared to the class structure generated by parent-report ADHD information.

METHODS

Self-reported DSM-IV Criterion A ADHD symptoms of 497 adolescent males from a population-based twin study in the state of Missouri (USA) were subjected to principal components and latent class analysis, and findings were compared to previous results obtained from identical analyses using an adolescent sample from Porto Alegre, Brazil (N = 483).

RESULTS

The bi-dimensional structure of self-reported ADHD symptoms was similar for both male adolescent groups, but explained less than 40% of the symptom variance in either sample. Two factors, one with loadings on inattention symptoms only and the other with loadings on hyperactive-impulsive symptoms only, were identified in the Missouri sample. Specific ADHD latent classes did not replicate well across the Missouri and Brazilian samples, and both groups were characterized by the presence of several combined symptom classes but few inattentive or hyperactive-impulsive classes.

CONCLUSIONS

While adolescent-report information across two different cultures can at least in part reproduce the two-factor structure of ADHD, results from latent class analysis suggest that adolescent reporting on their own symptoms is markedly different from the type of information parents provide about ADHD symptoms in their offspring. The current findings indicate that if male adolescents endorse any ADHD symptoms there is a tendency for them to report combined type problems.

Dopamine transporter gene and response to methylphenidate in attention-deficit/hyperactivity disorder

This study aims to evaluate whether a previously reported association between homozygosity for the 10-repeat allele of the dopamine transporter gene (10/10) and poor response to methylphenidate (MPH) would be replicated in a sample of Brazilian attention deficit/hyperactivity disorder (ADHD) boys. In a blind naturalistic study, 50 male ADHD youths were treated with MPH. Efficacy of the medication was measured by means of the 10-item Conners Abbreviated Rating Scale (ABRS), and the Children's Global Assessment Scale (CGAS). While 75% (15/20) of the youths without 10/10 genotype demonstrated an improvement higher than 50% in the ABRS scores with MPH, only 47% (14/30) of the subjects with 10/10 genotype achieved the same level of improvement with medication (one-tailed P = 0.04). In addition, the group without this genotype had significantly higher increase in the CGAS scores than the other group (one-tailed P < 0.01). Our findings support an association between homozygosity for the 10-repeat allele at dopamine transporter gene locus and poor response to MPH.

Discrimination of DSM-IV and latent class attention-deficit/hyperactivity disorder subtypes by educational and cognitive performance in a population-based sample of child and adolescent twins

OBJECTIVE

Despite the general use of DSM-IV attention-deficit/hyperactivity disorder (ADHD) subtypes, there is controversy over the optimal phenotyping strategy for this disorder.This report contrasts two ADHD subtyping approaches on the prediction of cognitive function and educational achievement.

METHOD

ADHD subtypes were determined using DSM-IV and latent class approaches for a population sample of 1,154 child and adolescent twins using parent report data. Twins completed cognitive and achievement testing and parents reported on school grades, special education placement, and history of being held back in school.

RESULTS

The DSM-IV primarily inattentive and combined subtype ADHD groups showed significant deficits in cognitive and achievement testing, worse grades, and increased use of special education resources compared with the primarily hyperactive/impulsive subtype and no-ADHD groups. Clinically relevant and less severe latent class ADHD subtypes were also associated with deficits in cognitive and achievement testing, grades, and special education use.

CONCLUSIONS

DSM-IV primarily inattentive and combined subtypes of ADHD have similar significant patterns of cognitive and academic dysfunction in the general population. Latent class-defined ADHD subtypes also have patterns of serious cognitive and achievement deficits.

School dropout and conduct disorder in Brazilian elementary school students

OBJECTIVES

To evaluate the association between DSM-IV conduct disorder (CD) and school dropout in a sample of students from the third and fourth elementary grades at state schools in the capital of the southernmost state of Brazil.

METHODS

In this case-control study, students that dropped out of schools (n = 44) and a control group who continued attending schools (n = 44) were assessed for CD and other prevalent mental disorders, using the Schedule for Affective Disorders and Schizophrenia for School Age Children, Epidemiological Version (K-SADS-E).

RESULTS

The prevalence of DSM-IV CD was significantly higher in the school-dropout group than in control subjects (P < 0.001), both in the entire sample and in a subsample including only subjects under age 12 years (P = 0.001). Also, the odds ratio (OR) for school dropout was significantly higher in the presence of DSM-IV CD, even after controlling for potential confounding factors (age, estimated IQ, school repetition, family structure, and income) (P < 0.01).

CONCLUSION

Our results extend to children and young adolescents previous findings from studies of older adolescents, suggesting an association between school dropout and CD.

Validity of DSM-IVADHD subtypes in a nationally representative sample of Australian children and adolescents

OBJECTIVE

To examine the discriminant validity of DSM-IV attention-deficit/hyperactivity disorder (ADHD) subtypes in a nationally representative sample of Australian youths.

METHOD

The Diagnostic Interview Schedule for Children, including the symptom-specific impairment questions, was administered to 3,597 parents of children aged 6 to 17 years (response rate = 70%). Parents also completed questionnaires assessing children's emotional and behavioral problems and quality of life.

RESULTS

Current DSM-IVADHD prevalence was 7.5% (6.8% with impairment) with inattentive types being more common than hyperactive-impulsive and combined types. ADHD was more prevalent among young males and was linked to social adversity, particularly for combined types. Compared with non-ADHD controls, all three ADHD subtypes were rated as having more emotional and behavioral problems and lower psychosocial quality of life, with combined types consistently rated the most impaired. Combined types received higher ratings than hyperactive-impulsive and inattentive types on externalizing behavior problems, disruption to family activities, and symptom-specific impairments with schoolwork and peer-related activities. Inattentive types were rated as having lower self-esteem, more social and school-related problems, but fewer externalizing problems than hyperactive-impulsive types.

CONCLUSION

These findings support the view of DSM-IVADHD subtypes as distinct clinical entities with impairments in multiple domains.

Attention-deficit hyperactivity disorder: a study of association with both the dopamine transporter gene and the dopamine D4 receptor gene

Attention-deficit hyperactivity disorder (ADHD) is one of the most common psychiatric disorders of childhood. The role of genetic factors in its etiology is strongly supported by family, adoption, and twin studies. Several investigations have reported associations between ADHD and both the 7-repeat allele of the 48 bp VNTR at the DRD4 gene and the 10-repeat allele of the 40 bp VNTR at the DAT1 gene, but the results have been inconsistent. A sample of 81 Brazilian ADHD children and adolescents and their parents were screened for these DRD4 and DAT1 VNTRs. An excess of the DRD4 7-repeat allele was observed when both ADHD probands and their parents were compared with an ethnically matched control sample (chi-square = 11.55, P = 0.03; chi-square = 12.17, P = 0.03, respectively). However, haplotype relative risk (HRR) analysis showed no preferential transmission of the DRD4 7-repeat allele. No evidence of association with the DAT1 polymorphism was detected by both approaches. Nevertheless, an interaction effect of both genes on ADHD hyperactive/impulsive dimension was observed (F = 4.68; P = 0.03). These results add to the group of studies that together suggest a small effect of these genes in the susceptibility to ADHD.

Factor and latent class analysis of DSM-IVADHD symptoms in a school sample of Brazilian adolescents

OBJECTIVE

To evaluate the validity of the multidimensional construct proposed by DSM-IV for the diagnosis of attention-deficit/hyperactivity disorder (ADHD) in a school sample of young Brazilian adolescents.

METHOD

An instrument including all 18 DSM-IVADHD symptoms was administered to 1,013 students aged 12 to 14 years at 64 state schools by trained research assistants. Each symptom was rated on a Likert scale with five levels of severity (never, almost never, sometimes, frequently, and always).

RESULTS

Using an exploratory factor analytic approach (principal components analysis), two factors were extracted. Factor I (hyperactivity-impulsivity) comprised eight DSM-IV hyperactive-impulsive symptoms with loadings > or =0.40. Factor II (inattention) included also eight DSM-IV symptoms of inattention. The two factors explained 34% of the total variance and had an interfactor correlation of 0.45. Latent class analysis demonstrated similar classes in males and females, but class structures were markedly different from previous analyses of parent report data.

CONCLUSION

The findings support the appropriateness of the multidimensional construct introduced by DSM-IV in the diagnosis of ADHD in a different culture but emphasize the possible impact of different reporters on the results of structural model-testing.