On the 1st november 2011 the data sampling and data entry for the International ADHD in Substance Use Disorders Prevalence (IASP) study is closed. A rough calculation of the sample included: close to 3500 screenings, of which approximately 1100 full assessments!

Thanks to the project leaders and project teams for the huge efforts that have been made to sample these data, most often with very little budget. Thanks also to all the institute management for making the IASP study possible. And of course thanks to the patients for their collaboration. 

Whithout prior funding, ICASA has sampled an enormous amount of data. These data will be of huge value, for reaching the ICASA Foundation goals:
1) Decrease of the number of children/adolescents with ADHD that develop Substance Use Disorders;
2) Increase of quality of diagnoses and treatment of patients with both ADHD and SUD. 


In January 2015 a replication study of the IASP started its datacollection: IASP 2. Researchers from South Africa and Puerto Rico will sample data up until the end of 2016. They not only replicate the IASP study, but will add data on the development (age of onset) of ADHD, ODD and CD symptoms, and they will collect more (compared to the IASP-1 study) data on nicotine use and dependence in the groups of treatment seeking SUD patients with and without ADHD.

The IASP study (International ADHD in Substance use disorders Prevalence) investigates:

  • Prevalence rates of ADHD in treatment seeking patients with Substance Use Disorders. The differences and similarities between countries and between different substances and treatment settings are being investigated;
  • Course and development of SUD in patients with and without ADHD;
  • The validity of screening and diagnostic procedures for ADHD in this population.

The IASP study (formerly known as EASP, E for European) started at the end of 2009. Data sampling will cease in October 2011 and the first results are expected in 2012. In 9 European countries, the USA and in Australia data on ADHD, other disruptive behaviors and SUD will be sampled an analyzed. Over 5000 treatment seeking SUD patients will be included.

Funding of the IASP study

For an international study of this scale, central organization is crucial. Purchase of research instruments, translation of these instruments and training of the local project teams is necessary. Also, the local sites need funding for sampling the DATA.
Funding the IASP was split in three different parts:

  1. Central Organization before starting up the study.
    The central organization was located at the Trimbos-institute in the Netherlands. Funding was obtained via participating institutes, such as the University Hospital Vall d'Hebron in Barcelona, the University of Amsterdam and the Karolinska institute in Stockholm. Furthermore, 4 pharmaceutical companies (Janssen Cilag, Eli Lilly & Company, Shire, UCB) supported this part of the study with unrestricted grants, meaning that these companies had no influence on the research methods, researchers or results.
  2. Funding for the local participating sites.
    Each participating site is responsible for funding its own part of the study.
  3. Data collection, analyses and publication of results. 
    ICASA established a PhD position at the University of Amsterdam for doing this part of the study, which will result in a PhD thesis in 2012/2013. ICASA succeeded in finding funding for this position via private funding foundations: the Waterloo Foundation (UK), the Noaber Foundation (the Netherlands) and the Augeo Foundation (the Netherlands).