[The influence of different diagnostic criteria and the culture on the prevalence of attention deficit hyperactivity disorder]

AIM

To compare the prevalence of attention deficit disorder and hyperactivity disorder (ADHD) using different diagnostic criteria (DSM-IV-TR versus ICD-10) and two specific scales based on DSM IV (ADHD-IV Rating Scales and SNAP-IV p90) in school-age children (6-12 years).

PATIENTS AND METHOD

. A population-based study applying stratified multistage sample design (by courses), proportional to the type of school (public, private and enterd) and demographic areas (rural, city). From a target population of approximately 30 000 subjects a sample of 1509 children.

RESULTS

The prevalence rates of ADHD were within the expected range: 3.6% (95% CI = 2.6-4.6%) using DSM-IV criteria, 1.2% (95% CI = 0.6-1.8%) using the ICD-10, 4.6% (95% CI = 3.5-5.7%) using ADHD Rating Scales-IV with a cut-off of 90 percentile 4.11% (95% CI = 3.2-5.1%) using the scale SNAP-IV. However, we found some differences in reference to gender and subtype according to the criteria and instrument used.

CONCLUSIONS

We propose to use standard scales, scale by age, sex and evaluator that includes maturation and sociocultural factors help us draw conclusions about the true prevalence of ADHD.

[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.