[Attention deficit disorder and hyperactivity: a pattern of evolution?]

INTRODUCTION

When the frequency of a gene in the general population exceeds 1%, is not considered a random mutation but a mutation that has been positively selected during evolution. The high prevalence of attention deficit/hyperactivity disorder (ADHD) from 5-10% and its association with the seven-repeat allele of DRD4, which is positively selected in evolution, raising the possibility that ADHD increases the reproductive fitness of the individual and/or group. One of the main characteristics of ADHD is its diversity and is a well recognized fact that diversity confers many benefits to a population (eg. immunity).

DEVELOPMENT

This article discusses the various studies that support this hypothesis and offers further explanations on the prevalence, age distribution and sex distribution of the severity and heterogeneity of ADHD.

CONCLUSION

It is possible that the presence of altered gene combinations, as in ADHD, can bring concrete benefits to society but are detrimental to the individual.

[What combination of symptoms according to parents and teachers would be more reliable for the diagnosis of ADHD?]

INTRODUCTION

The polythetic method used in the DSM is the one proposed traditionally for the diagnosis of Attention Disorders with or without Hyperactivity (ADHD). However, it is possible that the approach which aggregates any combination of 6 items won't be the optimal method to establish a diagnosis of ADHD, and that the different combinations may not be the same as regards to their ability to predict ADHD.

AIM

Determine which combinations of items of DuPaul's inattention and hyperactivity-impulsivity scales (from parent and teacher versions), are the most effective to predict or rule out a diagnosis of ADHD.

RESULTS

Not every combination of items from parents and teachers obtained the same predictive value. All of them offered high levels of specificity, but had low sensivity; that is to say, the combinations were more effective and reliable for ruling out the disorder than predicting it.

CONCLUSIONS

Data show that not every combination of ADHD items has the same predictive value and, therefore, the well-known polythetic method is disputable. The highest predictive value combinations, limitations of the study, and future lines of investigation are analyzed.

[Oppositional defiant disorder: aspects related to sex differences and informant]

INTRODUCTION

Oppositional defiant disorder (ODD) is one of the most common externalizing disorders in childhood. ODD prevalence global rates vary from 2% to 16%. Along with conduct disorder and attention deficit disorder, ODD is one of the leading reasons for referral to neuropediatric and psychiatric services. Even though ODD has recognized clinical importance, key aspects of its conceptualization and prevalence in childhood and adolescence remain uncertain.

DEVELOPMENT

We examine previous research findings of ODD prevalence and analyze sex differences and differences according to informants.

CONCLUSIONS

ODD prevalence rates present high variability. A number of studies suggest that ODD is more common in boys than in girls. Nevertheless, some authors point that this sex differences may be due to methodological bias. We recommend the validation of an ODD scale that has into consideration the following aspects: level of the subject's development (age), gender and environment.

[Attention deficit hyperactivity disorder: the state of the matter and further research approaches]

AIM

This paper is a review on the state of affairs of attention deficit hyperactivity disorder.

DEVELOPMENT

In the first section, the authors review the limitations and controversies in the fields of the prevalence, etiology, diagnostic criteria and comorbidities. In the second part, there is an update of the latest findings in the field of the neurobiological bases, the genetic etiology, the relevance of the evaluation of the executive functions and the effectiveness of drug therapies, behavioral and others alternatives therapies. The authors have selected the most relevant recently published bibliography and addressed in a schematic way, disputes or outstanding issues with a greater emphasis on the lines of research more relevant in the near future.

[Soft neurological signs: are they of any value in the assessment and diagnosis of attention deficit hyperactivity disorder?]

INTRODUCTION

The association between difficulties on motor skills, visual-hand coordination and excess motor activity was described previously of being established the attention-deficit/hyperactivity disorder (ADHD) as a diagnostic category. These disorders have been grouped under different terminologies, being one of them the soft neurological signs (SNS). Traditionally, the European scientific community has put more attention on the SNS than the American one. However, nowadays there are a lot of neuropediatrician and community pediatrician that continue to think that those deficits, together with inattention and hyperactivity, form part of the same disorder.

DEVELOPMENT

In this article we have tried to do a neurobiological revision of the movement and the possible relationship between motor problems and cognitive processes from different points of view: neuroanatomical, findings on different clinical examination tests and neuropsychological experimental models.

CONCLUSION

Most of the revised articles conclude that the SNS prevalence is greater in ADHD children compared with control. Therefore we recommend to include the SNS in the evaluation and diagnosis protocols of these disorders in order to improve the sensitivity and specificity of the diagnosis and to be able to evaluate the real needs of the ADHD patients.

[ADHD Rating Scale-IV in a sample of Spanish schoolchildren: normative data and internal consistency for teachers and parents]

INTRODUCTION

The ADHD Rating Scale-IV (ADHD RS-IV) is one of the most use scales for attention deficit hyperactivity disorder (ADHD), because has cut-off point regarding age, gender and setting, but the normalization data is based on American school samples.

AIM

Evaluation of cut-off point of ADHD-RS-IV for parents and teachers in a Spanish sample.

SUBJECTS AND METHODS

The study used the score of ADHD-RS-IV from a prevalence study of ADHD in school children of 6-12 years. Using an intrasubject design between the three evaluators (parents and teachers) and the results of each subscale (IN, H/I, and TOT) according to gender and age factors. Then, we analyzed the reliability and internal consistency for each subscale and evaluator.

RESULTS

There are no significant differences between the father and the mother; but there are between teachers, and father and/or mother scores. In relation to gender factor, boys' score is higher on inattention and hyperactivity-impulsivity than girls'. Our results show a reversal tendency in comparison with the American samples, in our case parents' scores were significantly higher than teachers'.

CONCLUSION

The use and normalization of the ADHD RS-IV will need to account not only for age, gender and setting but also for socio-cultural aspects.

[The predictive value of DSM-IV criteria in the diagnosis of attention deficit hyperactivity disorder and its cultural differences]

INTRODUCTION

The most common method used to diagnose attention deficit/hyperactivity disorder (ADHD) is based on the Diagnostic and statistic manual of mental disorders, 4th edition (DSM-IV) criteria. Nevertheless, it is more likely that the categorical system postulated by DSM-IV is not the most appropriate method as it does not consider the possible differences between the diagnostic capacity of the 18 proposed criteria. AIM. To analyze the predictive power of each DSM-IV diagnostic symptoms/criteria for ADHD using DuPaul's ADHD Parent and Teacher Rating Scales.

PATIENTS AND METHODS

In a prospective, poblational study to evaluate the prevalence of ADHD the positive predictive power of each item was analyzed for each subtype and informant. A kappa index was applied for positive predictive power to correct the number of accurate predictions based on chance factors, and a ranking of items was established to determinate which ones offered the highest predictive power, comparing parent and teacher ratings.

RESULTS

The results suggest that not all DSM-IV criteria are equal with regard to their ability to predict ADHD. The predictive power varies as a function of the informant. Parent and teachers agreed more on hyperactivity and impulsivity items, and showed more significant differences with regard to the American sample.

CONCLUSIONS

The approach that aggregates any combination of items will not be the more effective strategy for ruling in a diagnosis of ADHD. To improve the clinical value of these scales making item combinations is recommended, the ones that will have attached a higher clinical weight for ruling in a diagnosis of ADHD.

[Estimation of the prevalence of attention deficit hyperactivity disorder among the standard population on the island of Majorca]

AIM

To determine the rate of prevalence of attention-deficit/ hyperactivity disorder (ADHD) in children of school age (6-11 years) in the Island of Mallorca.

SUBJECTS AND METHODS

The epidemiological study was conducted using a community sample extracted by means of multi-stage stratified sampling according to areas (rural, city and touristy) and schooling (public, private and concerted) and consisted in 1,509 children of both sexes. The ADHD Rating Scales-IV (ADHD RS-IV) for home and school setting were used to collect data. The optimal approach to do a diagnostic evaluation, according with the literature, was using a cut-off point of 90 centil.

RESULTS

The estimated prevalence of ADHD was 4.57% (CI at 99%: 3.0-5.8%) and we also obtained 1.26% for the hyperactive subtype, 1.06% for the disattentional subtype, and 2.25% for the combined subtype. Contrary to what was expected, prevalence was higher for females but no statistically significant. There were no statistically significant differences between levels, schools or areas.

CONCLUSIONS

The estimates for prevalence found in this study are consistent with those reported in the literature (between 3-5%). Using the ADHD rating scale which has different cut-off point regarding age, sex and setting and the fact that it was a poblational based study could explain the higher prevalence in the females. We propose a normalization of the scales in our area in other to confirm our findings.

[Methylphenidate in the treatment of attention-deficit/hyperactivity disorder: are we achieving an adequate clinical practice?]

INTRODUCTION

Attention-deficit/hyperactivity disorder (ADHD) is the most frequent behavioural disorder in infancy and methylphenidate is the most widely used medication. AIM. To analyze if the use of methylphenidate allows a good clinical practice in ADHD in terms of efficacy, effectiveness, efficiency and safety.

MATERIALS AND METHODS

Systematic review of the articles about therapeutic management of ADHD with methylphenidate published in secondary and primary publications and critical appraisal by means of methodology of the Evidence-Based Medicine Working Group.

RESULTS

The main secondary information is found in the Cochrane Library, but we also detect relevant articles in Pubmed, mainly published in Journal of the American Academy of Child and Adolescent Psychiatry and Pediatrics. There are many randomized clinical trials with methylphenidate (immediate-release and extended-release methylphenidate) and some systematic review and/or meta-analysis, but these trials have some limitations (in relation to patients, interventions and outcomes) and publication bias.

CONCLUSIONS

From the evidence-based analysis (and from the experience) we detect good scientific evidence that methylphenidate improve target outcomes in ADHD in the short and half-term in children (mainly 6-12 years). The treatment algorithm advises to start with methylphenidate (immediate or extended-release methylphenidate, in relation to cost-benefit parameters); when there is not response (between 10-30% of patients) or evidence of relevant secondary effects, we could consider the use of atomoxetine. There are many questions to solve based on better clinical trials: the efficacy and safety of methylphenidate in very young children and adolescents, long-term effects and the duration of the treatment.