Attention-Deficit/Hyperactivity Disorder in Young Males: The Medicalization of Boyhood?

To describe the psychometric properties of the Strengths and Difficulties Questionnaire (SDQ), a brief measure of the prosocial behavior and psychopathology of 3-16-year-olds that can be completed by parents, teachers, or youths. A nationwide epidemiological sample of 10,438 British 5-15-year-olds obtained SDQs from 96% of parents, 70% of teachers, and 91% of 11-15-year-olds. Blind to the SDQ findings, all subjects were also assigned DSM-IVdiagnoses based on a clinical review of detailed interview measures. The predicted five-factor structure (emotional, conduct, hyperactivity-inattention, peer, prosocial) was confirmed. Internalizing and externalizing scales were relatively "uncontaminated" by one another. Reliability was generally satisfactory, whether judged by internal consistency (mean Cronbach a: .73), cross-informant correlation (mean: 0.34), or retest stability after 4 to 6 months (mean: 0.62). SDQ scores above the 90th percentile predicted a substantially raised probability of independently diagnosed psychiatric disorders (mean odds ratio: 15.7 for parent scales, 15.2 for teacher scales, 6.2 for youth scales). The reliability and validity of the SDQ make it a useful brief measure of the adjustment and psychopathology of children and adolescents.

The worldwide prevalence estimates of attention deficit hyperactivity disorder (ADHD)/hyperkinetic disorder (HD) are highly heterogeneous. Presently, the reasons for this discrepancy remain poorly understood. The purpose of this study was to determine the possible causes of the varied worldwide estimates of the disorder and to compute its worldwide-pooled prevalence. The authors searched MEDLINE and PsycINFO databases from January 1978 to December 2005 and reviewed textbooks and reference lists of the studies selected. Authors of relevant articles from North America, South America, Europe, Africa, Asia, Oceania, and the Middle East and ADHD/HD experts were contacted. Surveys were included if they reported point prevalence of ADHD/HD for subjects 18 years of age or younger from the general population or schools according to DSM or ICD criteria. The literature search generated 9,105 records, and 303 full-text articles were reviewed. One hundred and two studies comprising 171,756 subjects from all world regions were included. The ADHD/HD worldwide-pooled prevalence was 5.29%. This estimate was associated with significant variability. In the multivariate metaregression model, diagnostic criteria, source of information, requirement of impairment for diagnosis, and geographic origin of the studies were significantly associated with ADHD/HD prevalence rates. Geographic location was associated with significant variability only between estimates from North America and both Africa and the Middle East. No significant differences were found between Europe and North America. Our findings suggest that geographic location plays a limited role in the reasons for the large variability of ADHD/HD prevalence estimates worldwide. Instead, this variability seems to be explained primarily by the methodological characteristics of studies.

Overdiagnosis and underdiagnosis of attention-deficit/hyperactivity disorder (ADHD) are widely debated, fueled by variations in prevalence estimates across countries, time, and broadening diagnostic criteria. We conducted a meta-analysis to: establish a benchmark pooled prevalence for ADHD; examine whether estimates have increased with publication of different editions of the Diagnostic and Statistical Manual of Mental Disorders (DSM); and explore the effect of study features on prevalence.