Findings are mixed on the relationship between attention-deficit hyperactivity disorder (ADHD) and younger relative age in the school year. We aimed to investigate whether relative age is associated with ADHD diagnosis in a country where prescribing rates are low and whether any such association has changed over time or relates to comorbid disorders (eg, conduct disorder [CD], oppositional defiant disorder [ODD], or learning disorder [LD]).

中文翻译：

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学年内的相对年龄和注意缺陷多动障碍的诊断：一项基于全国的人口研究。

关于注意力缺陷多动障碍（ADHD）和学年中相对年轻年龄之间关系的研究结果参差不齐。我们的目的是调查在处方率较低的国家/地区，相对年龄是否与ADHD诊断有关，以及这种关联是否随时间变化或与合并症（例如行为障碍[CD]，对立违抗性障碍[ODD]，或学习障碍[LD]）。