ADHD-Europe

It has long been known from clinical follow-up studies that children with attention-deficit hyperactivity disorder (ADHD) often continue to have symptoms in adulthood, that symptoms of inattention are more likely to persist into adulthood than symptoms of hyperactivity or impulsivity and that adults with a history of childhood ADHD have a comparatively high prevalence of other mental disorders that develop subsequent to ADHD and might be to some extent consequences of primary ADHD; however, adult ADHD has only recently become the focus of widespread clinical attention. Not only is the study of adult ADHD comparatively new, it is also characterised by controversy due to lack of agreement on appropriate diagnostic criteria and the realisation that diagnosis is complicated by symptom overlap with a number of other disorders.

As adult ADHD was not included in any of the major psychiatric epidemiological surveys that have been carried out around the world since the landmark Epidemiologic Catchment Area study in the early 1980s, attempts to estimate adult ADHD prevalence have been based either on extrapolations from childhood prevalence estimates using information from clinical studies regarding the proportion of childhood cases that persist into adulthood  or on direct estimates from small samples. Most of the studies of either type have taken place in the USA, where estimates of adult ADHD prevalence are in the range 1–6%. A review by Faraone et al  based on 20 studies in the USA and 30 studies in other countries found that prevalence estimates of childhood and adolescent ADHD were as high in many non-US studies as in US studies. Studies of adult ADHD in non-US populations, though, are much rarer. The only general-population non-US study took place in a town in The Netherlands (Kooij et al, 2005), but absence of information on age of onset and pervasiveness of symptoms made it impossible to generate an unbiased prevalence estimate of adult ADHD in this population. In order to obtain more accurate estimates of prevalence and correlates of adult ADHD, a screen for this  disorder was developed for use in the World Health Organization World Mental Health (WMH) surveys. We present here the results from the ten WMH surveys that included this screen.

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