Incidence and prevalence of drug-treated attention deficit disorder among boys in the UK.

BACKGROUND Drug treatment for attention deficit disorder (ADD) was rare in the United Kingdom (UK) until in the mid-1990s. This contrasts with North America, where such treatment has been used to treat ADD for many decades. Since no quantitative data on the incidence and prevalence of drug-treated ADD are available in the UK, we used the general practice research database (GPRD) to obtain such information. AIMS To provide estimates of incidence and prevalence of treated ADD in the UK for the years 1996-2001. DESIGN OF STUDY Follow-up study of boys aged 5-14 years. SETTING Data from UK general practices. METHODS From the GPRD, we identified all boys aged 5-14 years who were prescribed methylphenidate for ADD. Based on the population in that age and sex category, we estimated incidence rates and the prevalence for treated ADD for the years 1996-2001. RESULTS The incidence of first-time diagnosis of treated ADD increased among boys from the age of 5 years to reach a peak in boys aged 9-10 years, after which the incidence rate decreased. No material change in incidence was noted during the years 1996-2001. The prevalence of treated ADD was estimated to be 5.3 per 1000 boys in 1999. CONCLUSION Drug treatment for ADD for boys treated for this disorder in the UK is substantially lower than the proportion of boys treated in North America.