Objective: It would be useful to compare temporal changes in the diagnostic prevalence of ADHD obtained from identical population surveys with time-trend survey findings based on individual ADHD features. Method: Changes in the diagnostic prevalence of ADHD over time were recorded from parent reports and from physician office visit data. Associated features of ADHD were temporally recorded from standardized teacher, parent, and youth surveys. Results: Time-trend diagnostic findings on ADHD prevalence based on 6 parent surveys and 12 outpatient physician office visit surveys revealed consistent rate increases. By contrast, 26 sets of standard ratings of the primary and associated features of ADHD assessed systematically by different teachers, parents, and students during different years indicated little change. Conclusion: Time-trend national surveys of ADHD in youth over the last two decades reveal consistent increases in its diagnostic prevalence, whereas time-trend findings for individual ADHD-related symptoms remained relatively stable.