Attention-deficit/hyperactivity disorder in schoolchildren in Crete

To explore the prevalence of attention-deficit/hyperactivity disorder (ADHD) in 7-y-old child residents of Crete, Greece.

The study combined information from both parents and teachers for 1708 elementary school children attending the first grade in 101 classes of 55 primary schools. A two-stage screening process was employed, including the ADHD test and a rating scale of student behaviour. Parents completed the ADHD test and teachers the rating scale of student behaviour.

Both questionnaires were completed for 1285 (75.2%) children. Among them, 84 children (6.5%; 95% CI 5.2-7.9%) met the study criteria for ADHD. The estimated prevalence was 8.8% for boys (95% CI 6.6-11.0%) and 4.2% for girls (95% CI 2.6-5.7%). No significant differences were observed regarding urban, semi-urban or rural residence.

By using a combination screening procedure, both the ADHD prevalence among first-grade schoolchildren in Crete and the gender differences in prevalence were found to be comparable to those reported from other countries. The methods used and the problems faced illustrate the challenges involved in conducting population-based studies of ADHD.