Prevalence of ADHD drug discontinuance in adolescents and young adults was studied in the UK by using the General Practice Database for patients aged 15-21 years from 1999 to 2006. Prevalence of prescribing methylphenidate, dexamfetamine and atomoxetine across all ages increased 6-fold over the study period, but overall, prevalence decreased with age. In 2006, prevalence of prescribing in males dropped 95% from 12 per 1000 in 15-year-olds to 0.64 per 1000 in 21-year-olds. A longitudinal analysis of 44 patients aged 15 years in 1999 found no patient received treatment after age 21 years. The fall in prescribing by general practitioners in UK is greater than the reported age-related decrease in ADHD symptoms. 
COMMENT. The recent rapid increase in prescriptions for patients with ADHD in the UK is of interest, since practitioners in the UK have generally denied the existence of the syndrome and disapproved of its “medicalization.” At a meeting of pediatric neurologists in London in the 1970s, I was gently chided by my British colleagues for my interest in treatment of the behavior. Rutter M et al, in a study of 10- and 11-year-old children in the Isle of Wight, UK, reported a prevalence of less than 1 in 1000. (Education, Health and Behavior. London, Longman, 1970). In contrast, prevalence rate among school-age children in the US is estimated at 5%, and even higher when using the latest DSM diagnostic criteria . The decreased prevalence of prescribing noted in adolescents and young adults in the UK study is also noted among adults in a Hungarian study . The pooled prevalence of adult ADHD was 2.5%, and this decreased with increasing age. The reasons for the decline in prevalence of treated ADHD in young adults are unclear. Possible explanations include inadequate diagnostic criteria, and a paucity of neurologists and psychiatrists who address the problems of that transition period from late adolescence to adulthood. Pediatric neurologists, trained both in adult and pediatric medicine, are eminently qualified to care for this age group, but the geographic separation of the specialties may present an obstacle.