This study was designed to assess the prevalence of psychiatric disorders and the impact of impairment criteria on rates of diagnoses in a representative sample of elementary school children from a country in a region. We sampled 419 primary school children by using a one-stage design in Izmir, Turkey. The response rate was 99.5 % and 417 cases were assessed using the Schedule for Affective Disorders and Schizophrenia for School-Age Children Present and Lifetime Version and a scale to assess the impairment criterion. The results showed that 36.7 % of the sample met DSM-IV criteria independent of impairment and that 14.1 % of the population had one or more DSM-IV disorders when a measure of impairment specific to each diagnosis was considered. The most prevalent disorders were attention-deficit/hyperactivity disorder and anxiety disorders. This study provided the first estimates of the prevalence of specific DSM-IV-defined psychiatric disorders in Turkish population of children.

Our results confirmed a substantially higher ADHD prevalence rate (more than double) than the suggested pooled worldwide prevalence, although similar to the one recently detected in a representative populational sample of children in the US (11 %). These findings, consistent with previous developmental epidemiology studies from Turkey, confirm that ADHD is highly prevalent in Turkish elementary school children.

The American Psychiatric Association (APA) working group on Attention-Deficit/Hyperactivity Disorder (ADHD) proposed the inclusion of four new impulsivity symptoms. However, they were not included in DSM-5 due to the lack of sufficient evidence. The aim of this study is to investigate the performance of the proposed four ADHD impulsivity symptoms with respect to: (a) ADHD factor structure; (b) performance in predicting clinical impairment; (c) specificity for ADHD diagnosis and (d) best symptomatic threshold to predict clinical impairment. The sample comprised 416 children (31 ADHD subjects according to both DSM-IV and proposed DSM-5, 20 ADHD subjects according to just one diagnostic system and 365 controls) from 12 schools. Diagnoses were derived using semi-structured interviews and ADHD rating scales. Results from confirmatory factor analysis indicate that addition of the four new impulsivity items provided a slightly better factor structure if compared to models including only 18 items. Regression analyses showed that only one of the new impulsivity symptoms (impatient) was part of the list of best predictors of impairment. None of the four new impulsivity items was specifically associated with ADHD diagnosis. The best cutoff point in the hyperactivity/impulsivity dimension for predicting impairment did not change significantly. Overall, our findings suggest that the determination on how to best capture impulsivity dimension as part of the ADHD construct needs more investigation and that there is not enough evidence to include these four assessed impulsivity symptoms as part of the ADHD criteria.

No abstract