As awareness of ADHD has increased throughout the world, interest has grown beyond the constellation of ADHD symptoms, including long-term effects and impact on people's lives.

To examine the consequences of childhood ADHD and the relevance of these outcomes in different world regions.

This analysis examined the publication trends of studies of long-term outcomes of ADHD over time and among world regions.

Study identification followed Cochrane guidelines. Twelve databases were searched for reports published in English 1980–2010. Limiting criteria were designed to maximize study inclusion while maintaining a high level of study rigor: the studies were to

1. (1) be peer-reviewed,

2. (2) be primary study reports,

3. (3) include a comparator group or baseline, and

4. (4) report outcome results measured for a mean of 8 years (prospective studies, range of all studies was 6 months-40 years) after the start of the study, in late adolescence, or adulthood.

The fully-defined electronic search yielded 4615 citations, which were then reviewed manually based on the titles and abstracts, yielding a final of 371 studies.

Study publication trends analysed included: publication year, country and world region of origin, outcome types, and study types. In general, the numbers of studies published per year globally has increased substantially (from 2 in 1980 to more than 40/year in 2007 and 2008) with differences observed between Europe and North America.

Analysis of publication trends can provide insight into outcomes of ADHD and the focus of specific world regions.

Supported by Shire Development Inc.