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Context: The frequency of occurrence of attention-deficit/hyperactivity disorder (AD/HD) is in dispute. This uncertainty has contributed to the concern that too many children in the United States are being treated with stimulant medication. Objectives: To determine the cumulative incidence of AD/HD in a population-based birth cohort and to estimate the prevalence of pharmacologic treatment for children who fulfill research criteria for AD/HD. Design: Population-based birth cohort study. Setting and Subjects: All children born between 1976 and 1982 in Rochester, Minn, who remained in the community after age 5 years (N=5718). Main Outcome Measures: Medical and school records were reviewed for clinical diagnoses of AD/HD and supporting documentation (symptoms consistent with Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria and positive results for AD/HD-related questionnaires). Research-identified cases were defined as: (1) "definite" AD/HD (clinical diagnosis and at least one type of supporting documentation); (2) "probable" AD/HD (clinical diagnosis but no supporting documentation or no clinical diagnosis but both types of supporting documentation); (3) "questionable" AD/HD (no clinical diagnosis, but at least one type of supporting documentation); and (4) "not AD/HD" (all other subjects). Information about pharmacologic treatment for AD/HD was abstracted for all subjects. Results: The highest estimate of the cumulative incidence at age 19 years (with 95% confidence interval) of AD/HD (definite plus probable plus questionable AD/HD) was 16.0% (14.7-17.3). The lowest estimate (definite AD/HD only) was 7.4% (6.5-8.4). Prevalence of treatment with stimulant medication was 86.5% for definite AD/HD, 40.0% for probable AD/HD, 6.6% for questionable AD/HD, and 0.2% for not AD/HD. Conclusions: These results provide insight into the apparent discrepancies in estimates of the occurrence of AD/HD, with less stringent criteria resulting in... [ABSTRACT FROM AUTHOR]

OBJECTIVE. The aim of this study was to report the incidence rates and other epidemiologic characterizations of written-language disorder. There have been no epidemiologic studies on the incidence of written-language disorder in the United States, and the use of a population-based birth cohort, longitudinally followed, is the most powerful method for reaching this objective. METHODS. In this population-based, retrospective birth cohort study, subjects included 5718 children born between 1976 and 1982 in Rochester, Minnesota, who remained in the community after 5 years of age. Records from all public and nonpublic schools, medical facilities, and private tutorial services were reviewed and results of all individually administered IQ and achievement tests, and extensive medical, educational, and socioeconomic information, were collected. The essential features of writing problems from the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision were included in our operationalized definition of written-language disorder. Written-language disorder incident cases were established by using research criteria based on 3 formulas (regression-based discrepancy, non-regression-based discrepancy, and low achievement. RESULTS. Cumulative incidence rates of written-language disorder varied from 6.9% to 14.7% depending on the formula. Boys were 2 to 3 times more likely to be affected than girls regardless of the formula. Among all written-language disorder cases (N = 806), 25% (n = 203) had written-language disorder without a reading disability. Specifics of the writing problems were identified for 87% (n = 702) of written-language disorder cases. CONCLUSIONS. In this population-based birth cohort of school-aged children, written-language disorder was at least as frequent as reading disabilities and significantly more frequent among boys than girls. [ABSTRACT FROM AUTHOR]