The role of stimulants in the treatment of preschool children with attention-deficit hyperactivity disorder.

The symptoms of attention-deficit hyperactivity disorder (ADHD) can have an early onset, beginning before the age of 6 years. Despite the significant number of preschool-aged children that can be diagnosed with ADHD, there are limited controlled data available on the pharmacological interventions being increasingly used in this population. A 1990 review showed that 34% of paediatricians and 15% of family physicians had prescribed psychostimulant medications to preschoolers with ADHD, and pharmacoepidemiological studies indicate growing use of stimulants in preschoolers during the 1990s. Unfortunately, only six controlled trials, with a total enrollment of less than 200 children, have been conducted using these drugs in preschoolers. While these small studies provide some evidence of benefit from the use of methylphenidate in preschoolers with ADHD, more data are critically needed. Practice parameters developed by the American Academy of Child & Adolescent Psychiatry and the American Academy of Pediatrics provide some guidance regarding the diagnosis and treatment of young children with ADHD, but are mainly based upon research in children of primary-school age. The ongoing PATS (Preschool ADHD Treatment Study), funded by the National Institute of Mental Health, will provide important clinical guidance for diagnostic considerations and intervention strategies for children with ADHD aged 3-5 years. Pending the release of data from the PATS study, clinicians must rely on developmental assessment skills, available standardised rating instruments, reports about the child from multiple informants, and knowledge of the risks and benefits of available pharmacological and behavioural treatments, in order to treat preschool children with ADHD effectively.