Absence of gender effects on attention deficit hyperactivity disorder: findings in nonreferred subjects

Tic disorders and ADHD: answers from a world-wide clinical dataset on Tourette syndrome

BACKGROUND

Tourette syndrome (TS) is a neurodevelopmental disorder with frequent comorbidity with Attention- deficit-Hyperactivity disorder (ADHD). The impact of this association is still a matter of debate.

METHOD

Using the TIC database containing 6,805 cases, the clinical differences were ascertained between subjects with and without ADHD.

RESULTS

The reported prevalence of ADHD in TS was 55%, within the range of many other reports. If the proband was diagnosed with ADHD, a family history of ADHD was much more likely. ADHD was associated with earlier diagnosis of TS and a much higher rate of anger control problems, sleep problems, specific learning disability, OCD, Oppositional-defiant disorder, mood disorder, social skill deficits, sexually inappropriate behaviour, and self-injurious behaviour. Subjects with seizures and with Developmental Coordination Disorder also had high rates of ADHD. Anxiety disorder, however, was not more frequent. Preliminary data suggest that most behavioural difficulties in ADHD are associated with the Combined or Hyperactive-Impulsive Subtypes of ADHD. Every large site (>200 cases) had a significantly increased rate of anger control problems in cases with ADHD.

CONCLUSION

Subjects with TS have high rates of ADHD and complex associations with other disorders. Clinically the findings confirm other research indicating the importance of ADHD in understanding the behavioural problems often associated with the diagnosis of TS. Additional ADHD comorbidity should be taken into account in diagnosis, management, and training.

Developmental psychopathology of children and adolescents with Tourette syndrome--impact of ADHD

BACKGROUND

In Tourette syndrome (TS) as a neurodevelopmental disorder not only the tics but also the comorbid conditions change with increasing age. ADHD is highly comorbid with TS and usually impairs psychosocial functioning more than the tics. Its impact on further comorbidity during development is important for clinical practice and still a matter of debate.

METHOD

Aspects of developmental psychopathology considering the impact of ADHD were examined by logistic regression (year wisely) in a cross-sectional sample of children and adolescents (n = 5060) from the TIC database.

RESULTS

In TS+ADHD (compared to TS-ADHD) higher rates of comorbid conditions like OCD, anxiety disorders, CD/ODD and mood disorders were found in children (5-10 years). In adolescents (11-17 years) higher comorbidity rates in TS+ADHD remained only for CD/ODD and mood disorders. Accordingly, for OCD and anxiety disorders there was a steeper year wise increase of these comorbidities in TS-ADHD while it was a similar for CD/ODD and mood disorders in TS-ADHD as well as TS+ADHD.

CONCLUSION

Children with TS+ADHD have more comorbidities than the TS-ADHD group, whereas in both adolescent groups this did no longer hold for OCD and anxiety disorders. These findings indicate that in TS comorbid ADHD is associated with high rates of externalizing and internalizing problems, whereas TS without ADHD is associated only with internalizing problems in adolescence.

Die Prävalenz der Aufmerksamkeitsdefizit-/Hyperaktivitätsstörung (ADHS) bei Kindern und Jugendlichen in Deutschland

The cardinal symptoms of attention-deficit/hyperactivity disorder (ADHD) are inattention, hyperactivity and impulsivity. Etiologically, ADHD is mainly put down to genetic causes; it entails a considerable range of psychosocial problems for those affected and their social environment. The parents of a total of 7,569 boys (B) and 7,267 girls (G) aged 3-17 who took part in the German Health Interview and Examination Survey for Children and Adolescents (KiGGS) answered a self-administered questionnaire including an ADHD diagnosis question and the Strengths and Difficulties Questionnaire (SDQ). In addition behavioural observations of 7,919 children (aged 3-11) were carried out during the medical and physical tests. Participants whose parents reported that they had ever been given an ADHD diagnosis by a doctor or psychologist were classified as ADHD cases. Participants were classified as suspected cases of ADHD if they had a value of > or =7 on the SDQ inattention/hyperactivity scale. ADHD had ever been diagnosed in 4.8 % of the children and adolescents altogether (B: 7.7 %, G: 1.8 %). Another 4.9 % of the participants can be considered as suspected cases. Already 1.8 % of the preschoolers had been given an ADHD diagnosis. At primary school age (7-10 years old) the frequency of diagnosis rises sharply. At age 11-17, ADHD had ever been diagnosed in 1 in 10 boys and 1 in 43 girls. ADHD had been diagnosed significantly more frequently among participants of low socio-economic status (SES) than among participants of high SES. A diagnosis of ADHD is reported less often for migrants, they rank more frequently among the suspected cases. The discrepancy between confirmed and suspected cases of ADHD among migrants may point to lower diagnosis rates or lower utilization of medical services. The short- and long-term medical, social and health-economic effects of ADHD illustrate the major public health relevance of the disorder. As for prevention, the high share of genetic factors in ADHD etiology primarily suggests secondary prevention (early support and early diagnosis) and tertiary prevention measures. Further analysis of the KiGGS data could prospectively identify risk groups more precisely and refine preventional approaches.

Der Einfluss des Geschlechts auf die Selbstbeschreibung kindlicher ADHS-Symptome

Diagnosing attention deficit hyperactivity disorder (ADHD) in adults requires retrospective assessment of ADHD symptoms in childhood. The Wender Utah Rating Scale (WURS) and its German validated version (WURS-k) may offer a helpful tool to acertain relevant childhood problems associated with ADHD. Up to now validating data of the WURS-k were limited to male population. In a population of 69 female adult ADHD patients and 97 controls, ROC analysis indicated a sensitivity of 93% and specificity of 92% at a cut-off of 30 points in the WURS-k. This cut-off value is equivalent to those of males. Symptom report varies significantly by gender and females describe more internalizing problems while males report more externalizing behaviour. Regarding different subtypes according to DSM-IV males and females did not differ in the items of the WURS-k.

Parent-of-origin effects in attention-deficit hyperactivity disorder

The goal of the present study was to investigate parent-of-origin effects in attention-deficit hyperactivity disorder (ADHD). Parent-of-origin effects in ADHD may be due to differences in the relative quantity of risk factors transmitted by each parent. Alternatively, parent-of-origin effects may be produced by qualitative differences in the risks transmitted, such as those carried on the sex chromosomes or regulated by genomic imprinting. 60 children with maternal-only history of ADHD and 131 children with paternal-only history of ADHD were compared on three domains for which prior evidence suggested parent-of-origin effects may exist: core symptoms, disruptive behaviours and depression. Dependent variables were derived from previously validated, age-appropriate and standardized parent and teacher interviews and questionnaires. Depression levels were rated using the Child Depression Inventory. Consistent with previous research and the predictions derived from threshold models of ADHD etiology, the maternal history group received higher ratings of behavioural disorder (ADHD, conduct disorder and oppositional symptoms) than the paternal history group. Parent-of-origin effects were also observed for depression, with the paternal history group rating themselves as significantly more depressed than children in the maternal history group, particularly girls. Heightened paternal transmission relative to maternal is suggestive of genomic imprinting, and the interaction with proband sex indicates the involvement of the sex chromosomes or sex-specific physiological or hormonal factors. Interpretations of these data in terms of environmental and genetic factors, including epigenetic and sex-linked hypotheses, are explored.

Prevalence of methylphenidate use among Israeli children: 1998-2004

BACKGROUND

Use of methylphenidate for the treatment of attention-deficit hyperactivity disorder (ADHD) has increased throughout the world in the past decade. In Israel, as elsewhere, there is much debate regarding the diagnosis of ADHD and methylphenidate use. The aim of this study was to examine methylphenidate use rates for the treatment of ADHD among children in Israel during the years 1998-2004 with a special focus on prescriptions among girls.

STUDY DESIGN AND METHODS

This was a longitudinal population-based prevalence study wherein we reviewed the computerised database of a major health maintenance organisation (HMO). Subjects studied included all children living in the central district of Clalit HMO in Israel who were prescribed methylphenidate in the 7-year period from 1998-2004.

MAIN OUTCOME MEASURES AND RESULTS

The overall 1-year prevalence rate of methylphenidate use in children aged 0-18 years increased from 0.7% in 1998 to 2.5% in 2004, an increase by a factor of 3.54 (95% CI 3.31, 3.79). In 1998, the rate of methylphenidate prescription ranged from 0.20% among schoolgirls to 1.2% among boys, a 6-fold difference. In 2004, the rate of methylphenidate prescription ranged from 1.1% among schoolgirls to 3.8% among boys; the sex difference had narrowed to only 3.45. Except for kindergarten girls, methylphenidate utilisation increased for all ages from kindergarten to high school, both among boys and among girls.

CONCLUSION

The continuous increasing rate of methylphenidate use in Israel, especially among girls, represents a significant public health issue. There is a need for future research into the relationship between sex and ADHD diagnosis and treatment.

Desempenho neuropsicológico de tipos de transtorno do déficit de atenção e hiperatividade (TDAH) em tarefas de atenção visual

OBJETIVO: Comparar o desempenho dos tipos de TDAH em tarefas de seletividade, sustentação e atenção alternada, considerando tempo médio de reação, número de erros por ação e número de erros por omissão em teste computadorizado de atenção visual (TAVIS-III). MÉTODOS: Cento e duas crianças e adolescentes de duas escolas particulares e uma escola pública da cidade do Rio de Janeiro, com idades entre 6 e 17 anos com diagnóstico de TDAH, segundo DSM-IV, foram submetidas ao TAVIS-III. A separação por grupos respeitou os tipos determinados por entrevista semi-estruturada (P-CHIPS), e os resultados foram comparados levando-se em consideração o fator grupo. RESULTADOS: O tipo combinado (C) revelou-se o mais comum (n = 65; 63,7%), seguido pelo predominantemente desatento (D) (n = 32; 31,4%). O tipo predominantemente hiperativo-impulsivo (HI) foi excluído das análises estatísticas em virtude da baixa freqüência. O desempenho do grupo C revelou-se inferior apenas em tarefa de atenção sustentada, no que tange ao número de erros por ação e tempo médio de reação (p < 0,05), ambos maiores quando comparados ao grupo D. CONCLUSÃO: Apenas em tarefa de atenção visual por tempo mais prolongado, o tipo combinado revelou diferenças significativas em relação ao grupo desatento.

Working memory deficits in adults with ADHD: is there evidence for subtype differences?

BACKGROUND

Working memory performance is important for maintaining functioning in cognitive, academic and social activities. Previous research suggests there are prevalent working memory deficits in children with attention deficit hyperactivity disorder (ADHD). There is now a growing body of literature characterizing working memory functioning according to ADHD subtypes in children. The expression of working memory deficits in adults with ADHD and how they vary according to subtype, however, remains to be more fully documented.

METHODS

This study assessed differences in working memory functioning between Normal Control (NC) adults (N = 18); patients with ADHD, Combined (ADHD-CT) Type ADHD (N = 17); and ADHD, Inattentive (ADHD-IA) Type (N = 16) using subtests from the Wechsler Adult Intelligence Scale-III and Wechsler Memory Scale-III and the Paced Auditory Serial Addition Task (PASAT).

RESULTS

The ADHD groups displayed significant weaknesses in contrast to the NC group on working memory tests requiring rapid processing and active stimulus manipulation. This included the Letter-Number-Sequencing test of the Wechsler scales, PASAT omission errors and the longest sequence of consecutive correct answers on the PASAT. No overall ADHD group subtype differences emerged; however differences between the ADHD groups and the NC group varied depending on the measure and the gender of the participants. Gender differences in performance were evident on some measures of working memory, regardless of group, with males performing better than females.

CONCLUSION

In general, the data support a dimensional interpretation of working memory deficits experienced by the ADHD-CT and ADHD-IA subtypes, rather than an absolute difference between subtypes. Future studies should test the effects of processing speed and load on subtype performance and how those variables interact with gender in adults with ADHD.

Influence of gender on attention-deficit/hyperactivity disorder in Europe--ADORE

BACKGROUND

Attention-deficit/hyperactivity disorder (ADHD) in girls in Europe is poorly understood; it is not known whether they exhibit similar symptom patterns or co-existing problems and receive the same type of treatment as boys.

OBJECTIVE

To examine gender differences for referral patterns, social demographic factors, ADHD core symptomatology, co-existing health problems, psychosocial functioning and treatment.

METHODS

Baseline data from the ADHD Observational Research in Europe (ADORE) study, a 24-month, naturalistic, longitudinal observational study in 10 European countries of children (aged 6-18 years) with hyperactive/inattentive/impulsive symptoms but no previous diagnosis of ADHD, were analysed by gender.

RESULTS

Data from 1,478 children were analysed: 231 girls (15.7%) and 1,222 boys (84.3%) (gender data missing for 25 patients). Gender ratios (girl:boy) varied by country, ranging from 1:3 to 1:16. Comparisons showed few gender effects in core ADHD symptomatology and clinical correlates of ADHD. Compared with boys, girls had significantly more parent-rated emotional symptoms and prosocial behaviour and were more likely to be the victim of bullying and less likely to be the bully. Girls and boys had similar levels of co-existing psychiatric and physical health problems, and received the same type of treatment.

CONCLUSIONS

Fewer girls than boys are referred for ADHD treatment, but they have a similar pattern of impairment and receive similar treatment.

Bias in psychopathology research

PURPOSE OF REVIEW

Biases are frequently invoked in psychopathology research, either as core features of particular forms of psychopathology or as errors and distortions that affect psychiatric assessment, diagnosis, treatment, and research methodology. This review provides an overview of recent research on the forms of bias that are commonly examined in the field.

RECENT FINDINGS

Recent research has made a number of advances in the analysis of cognitive and affective biases underpinning psychopathology: the effect of rating and other biases on psychiatric assessment and diagnosis; the role of race and gender in psychiatric practice; financial and institutional influences on psychiatric services; and several biases affecting research methodology, study design, and statistical inference.

SUMMARY

Bias has several distinct meanings, and encompasses a disparate set of phenomena, so no over-arching conclusion about the place of bias in psychopathology research can be drawn. Recent work, however, makes solid progress toward a better understanding of systematic distortions and how they can be recognized and reduced.

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.

Association between symptoms of attention-deficit/hyperactivity disorder and bulimic behaviors in a clinical sample of severely obese adolescents

OBJECTIVE

Preliminary evidence suggests a comorbidity between attention-deficit/hyperactivity disorder (ADHD) and obesity. This study was carried out to identify the clinical characteristics of obese adolescents with a higher probability of ADHD and advance the understanding of the potential factors underlying the comorbidity between obesity and ADHD. We evaluated the association between ADHD symptoms and bulimic behaviors, depressive and anxiety symptoms, degree of obesity, pubertal stage, age and gender in a clinical sample of obese adolescents.

DESIGN

Cross-sectional study.

SUBJECTS

Ninety-nine severely obese adolescents aged 12-17 years.

MEASUREMENTS

Subjects filled out the Bulimic Investigatory Test, Edinburgh, the Beck Depression Inventory and the State-Trait Anxiety Inventory for Children. Their parents completed the Conners Parent Rating Scale, which assesses ADHD symptoms. The degree of overweight was expressed as body mass index-z score. Puberty development was clinically assessed on the basis of Tanner stages.

RESULTS

Bulimic behaviors were significantly associated with ADHD symptoms after controlling for depressive and anxiety symptoms. The degree of overweight, pubertal stage, age and gender were not significantly associated with ADHD symptoms.

CONCLUSION

Obese adolescents with bulimic behaviors may have a higher probability to present with ADHD symptoms independently from associated depressive or anxiety symptoms. The degree of overweight, pubertal stage, age and gender might not be useful for detecting obese adolescents with ADHD symptoms. Therefore, we suggest systematic screening for ADHD in obese adolescents with bulimic behaviors. Further studies are needed to understand which specific dimension of ADHD primarily accounts for the association with bulimic behaviors. Future research should also investigate the causal link between bulimic behaviors and ADHD and explore potential common neurobiological alterations. This may lead to a better understanding of the effectiveness of stimulants for the treatment of bulimic behaviors in obese subjects.

Painel brasileiro de especialistas sobre diagnóstico do transtorno de déficit de atenção/hiperatividade (TDAH) em adultos

Considerando-se as dificuldades atuais do diagnóstico do transtorno do déficit de atenção/hiperatividade em adultos, foram reunidos especialistas brasileiros que fazem pesquisas nesta área, de modo a produzir diretrizes de consenso para uso no país. Foi realizada uma revisão não-sistemática preliminar e concebido um texto inicial, que foi repetidamente avaliado e editado pelos autores, com acréscimos e correções ao longo de 6 meses, através de correio eletrônico e de uma reunião posterior, patrocinada pela Associação Brasileira do Déficit de Atenção. A versão preliminar foi apresentada publicamente durante o congresso anual da Associação Brasileira de Psiquiatria, com comentários e sugestões dos participantes, para a redação da versão final.

Moment-to-moment dynamics of ADHD behaviour in South African children

Background

The behaviour of children with Attention-Deficit/Hyperactivity Disorder is characterized by low predictability of responding. Low behavioural predictability is one way of operationalizing intra-individual ADHD-related variability. ADHD-related variability may be caused by inefficient behavioural selection mechanisms linked to reinforcement and extinction, as suggested by the recently published dynamic developmental theory (DDT) of ADHD. DDT argues that ADHD is a basic neurobehavioural disorder, caused by dysfunctioning dopamine systems. For establishing ADHD as a neurobehavioural disorder, findings from studies conducted in Western countries should be replicated in other cultural populations. The present study replicated the study conducted in Norway, with children from the Limpopo province in the Republic of South Africa.

Methods

Boys and girls, aged 6–9 yr, from seven ethnic groups participated. Scores by teachers on the Disruptive Behavior Disorders rating scale defined participation in either ADHD-hyperactive/impulsive (-HI), ADHD-predominantly inattentive (-PI), or ADHD-combined (-C) groups. Children below the 86^th percentile were matched on gender and age and comprised the non-ADHD group. The children completed a computerized game-like task where mouse clicks on one of two squares on the screen resulted in delivery of a reinforcer according to a variable interval schedule of reinforcement. Reinforcers were cartoon pictures presented on the screen together with a sound. Predictability of response location and timing were measured in terms of explained variance.

Results

Overall, the results replicated findings from Norway. Specifically, the ADHD-C group showed significantly lower predictability of responding than the non-ADHD group, while the ADHD-HI and the ADHD-PI groups were in-between. In accordance with the previous study, response location, but not response timing, was a sensitive behavioural measure. There were no significant gender differences. Cartoon pictures were effective reinforcers as the non-ADHD group showed learning of the task. There was no relation between behavioural predictability and motor functions.

Conclusion

The present study makes a strong case for ADHD as a basic, neurobehavioural disorder, not a cultural phenomenon, by replicating findings from a wealthy Western country in a poor province of a developing country. The results were, generally, in line with predictions from the dynamic developmental theory of ADHD by indicating that reinforcers were less efficient in the ADHD group than in the non-ADHD group. Finally, the results substantiated ADHD-related variability as an etiologically important characteristic of ADHD behaviour.

A post hoc subgroup analysis of an 18-day randomized controlled trial comparing the tolerability and efficacy of mixed amphetamine salts extended release and atomoxetine in school-age girls with attention-deficit/hyperactivity disorder

BACKGROUND

Because the scientific literature on the pharmacotherapy of attention-deficit/hyperactivity disorder (ADHD) is almost entirely based on the results of studies in samples consisting primarily of boys, much is unknown about the treatment response in girls.

OBJECTIVE

This post hoc analysis compared the efficacy, tolerability, and time course of the effect of mixed amphetamine salts extended release (MAS XR) and atomoxetine in school-age girls with ADHD.

METHODS

This was an intent-to-treat subanalysis of the data from girls enrolled in a multicenter, 18-day, randomized, double-blind, parallel-group, forced dose-titration, laboratory school study enrolling boys and girls aged 6 to 12 years with ADHD. The study compared the efficacy, tolerability, and time course of the effect of increasing doses of MAS XR (10, 20, and 30 mg/d) and atomoxetine (0.5 and 1.2 mg/kg per day). The laboratory school sessions were organized in cycles to include 12 hours of observation. Efficacy measures included the SKAMP (Swanson, Kotkin, Agler, M-Flynn, and Pelham) deportment rating subscale, the SKAMP attention rating subscale, and academic testing (number of math problems attempted and answered correctly). Adverse events were assessed throughout the study period. Tolerability and efficacy measures were assessed during laboratory school visits on days 7, 14, and 21.

RESULTS

This subanalysis included 57 girls (median age, 9 years; 49.1% white, 22.8% black, 17.5% Hispanic) with a diagnosis of ADHD, combined subtype. Twenty-six girls were randomized to receive MAS XR and 31 were randomized to receive atomoxetine. Mean SKAMP deportment and attention subscale scores in the 2 groups were similar at baseline. Mean changes from baseline were significantly greater for MAS XR compared with atomoxetine on the SKAMP deportment score (-0.48 vs -0.04, respectively; P<0.001) and SKAMP attention score (-0.45 vs -0.05; P<0.001). The time course of medication effect, based on change from baseline in SKAMP deportment scores, indicated 12-hour efficacy for MAS XR at hours 2, 4.5, 7, 9.5, and 12 (all time points, P<0.01 vs baseline) but not for atomoxetine. At the end of the study, both treatment groups had a significant increase from baseline in the mean number of math problems attempted and answered correctly (P<0.001). Girls who received MAS XR attempted significantly greater numbers of problems compared with those who received atomoxetine (P=0.04). Both MAS XR and atomoxetine were well tolerated. The most frequently occurring treatment-related adverse events in girls receiving MAS XR were decreased appetite (40.7%), upper abdominal pain (29.6%), insomnia (25.9%), and headache (14.8%). The most frequently occurring treatment-related adverse events in girls receiving atomoxetine were somnolence (28.1%), upper abdominal pain (15.6%), vomiting (15.6%), nausea (12.5%), and decreased appetite (12.5%).

CONCLUSION

This post hoc analysis in a subpopulation of girls with ADHD, combined subtype, found that 18-day treatment with MAS XR was significantly more effective than atomoxetine in terms of ratings of classroom behavior, attention, and academic productivity.