Attention-deficit hyperactivity disorder (ADHD) is a rather novel disease in adults. It has drawn increasing attention and at present there is no deficit of studies of ADHD in adults (Reference Fayyad, De Graaf and KesslerFayyad et al, 2007). Several studies have shown a considerable risk of co-occurring substance misuse in adults given the diagnosis of ADHD (Reference AanonsenAanonsen, 1999; Reference WilsonWilson, 2007). Symptoms of ADHD seem to hamper success in methadone maintenance treatment (Reference Kolpe and CarlsonKolpe & Carlson, 2007). Fayyad et al indicate in Table 5 that in 99% of cases adult ADHD occurs first in patients with a co-occurring substance use disorder but this is not commented upon in the discussion part of their paper. Respondents were classified retrospectively as having met full ADHD criteria in childhood. To ascertain the presence of ADHD in adulthood respondents were asked a single question only, whether they continued to have problems with attention or hyperactivity.

In Norway we have an impression that people with substance misuse tend to ask for a diagnosis of ADHD, as this may lead to better treatment within the psychiatric care system. The finding of Fayyad et al of higher prevalences in high-income countries, with purportedly better services for the treatment of ADHD, may be an indication of common presenting symptoms in substance use disorder and ADHD. Could the authors have observed symptoms and behaviour related to substance misuse and not ADHD?