With onset often occurring before 6 years of age, attention-deficit/hyperactivity disorder (ADHD) involves attention problems, impulsivity, overactivity, and sometimes disruptive behavior. Impairment usually persists into adulthood, with an estimated worldwide prevalence in adults of 2.5%. Existing gaps in evidence concerning ADHD hinder decision-making about treatment. This article describes and prioritizes future research needs for ADHD in three areas: treatment effectiveness for at-risk preschoolers; long-term treatment effectiveness; and variability in prevalence, diagnosis, and treatment.Using a recent systematic review concerning ADHD completed by a different evidence-based practice center as a foundation, we worked with a diverse group of 12 stakeholders, who represented researchers, funders, healthcare providers, patients, and families, to identify and prioritize research needs. From an initial list of 29 evidence gaps, we enumerated 8 high-priority research needs: a) accurate, brief standardized diagnosis and assessment; b) comparative effectiveness and safety of pharmacologic treatments for children under 6 years of age; c) comparative effectiveness of different combinations of psychosocial and pharmacologic treatments for children under 6 years of age; d) case identification and measurement of prevalence and outcomes; e) comparative effectiveness of psychosocial treatment alone versus pharmacologic and combination treatments for children under 6 years of age; f) comparative long-term treatment effectiveness for people 6 years of age and older; g) relative efficacy of specific psychosocial program components for children under 6 years of age; and h) identification of person-level effect modifiers for people 6 years of age and older. In this article, we describe these future research needs in detail and discuss study designs that could be used to address them. (Journal of Psychiatric Practice 2014;20:104-117)
