Despite specific diagnostic criteria, published practice guidelines for assessing patients, and the availability of effective pharmacological treatments for children diagnosed with attention-deficit/hyperactivity disorder (AD/HD), a review of prescription practices in the United States indicates that as few as 25-50% of these patients receive even minimal medical treatment for this condition. Because untreated children with AD/HD are at increased risk for psychoactive substance abuse, criminal behavior, and other social problems as adults, the provision of effective care during childhood is essential. In order to clarify the factors impeding treatment during childhood and develop a targeted intervention to overcome these barriers, two studies involving 1514 families were conducted. Each family included one child diagnosed with AD/HD. Factors associated with treatment failure or non-compliance with medical advice included: dissatisfaction with a diagnostic process limited to brief observation, interview, and review of behavior rating scales; fear of stimulant medication; lack of medication response within the first month; development of side-effects during the first month; lack of understanding of the reasons stimulants were being prescribed for a child, and insufficient clinical response. Based on these findings, an intervention program consisting of a comprehensive evaluation process (that included neuropsychological and neurophysiological tests of attention, and medical screening for other health problems associated with inattention and hyperactivity) and parent education about the medical causes of AD/HD, the biochemical action of medications, the relationship between dietary habits and attention, and the educational rights of children with AD/HD was conducted. Following completion of this three session intervention, 95% of patients complied with medical recommendations, initiated pharmacological treatment, and continued medication for a 2-year follow-up period. Three percent of the patients were diagnosed and treated for other medical conditions.