Objective

Young relative age (ie, being among the youngest in a school class) and attention-deficit/hyperactivity disorder (ADHD) are both potential risk factors for adverse long-term outcomes. Young relative age also increases the risk of ADHD diagnosis. Using data from Swedish national registers, we investigate the independent and joint long-term effects of young relative age and ADHD on educational achievement, substance use disorder (SUD), criminality, and depression.

Method

We identified a national cohort of individuals with young relative age (born November–December) and a comparison group with old relative age (born January–February). Of the total sample of 297,840 individuals, 6,528 individuals had a diagnosis of ADHD in childhood. The 4 outcomes were measured at ages 15 to 23 years. We examined main, additive, and interactive effects of young relative age and ADHD on long-term outcomes.

Results

In the individuals without ADHD, young relative age was associated with increased risk of depression (odds ratio [OR] = 1.14 [95% CI =1.09–1.20]), SUD (OR = 1.14 [1.09–1.20]), and low educational achievement (OR = 1.17 [1.14–1.20]), but not criminality (OR = 1.00 [0.98–1.03]). In the individuals with ADHD, young relative age was associated with increased risk of SUD (OR = 1.23 [1.01–1.50]) and low educational achievement (OR = 1.12 [1.00–0.26]; CI included 1), but not depression or criminality (OR = 0.88 [0.73–1.07] and OR = 0.89 [0.79–1.01], respectively). An interaction emerged between young relative age and ADHD for depression (OR = 0.78 [0.64–0.95]).

Conclusion

We observed relative age effects that add to the evidence supporting a more flexible approach to school starting age and that emphasize the importance of careful age-match comparisons during assessment of childhood ADHD symptoms.

中文翻译：

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年轻相对年龄和注意力缺陷/多动障碍对负面长期结果的综合影响

客观的

相对年龄小（即在学校班级中年龄最小）和注意力缺陷/多动障碍 (ADHD) 都是不良长期结果的潜在危险因素。年轻的相对年龄也增加了 ADHD 诊断的风险。我们使用来自瑞典国家登记册的数据，调查年轻相对年龄和 ADHD 对教育成就、物质使用障碍 (SUD)、犯罪和抑郁症的独立和联合长期影响。

方法

我们确定了一个全国队列，其中包括相对年龄较小（11 月至 12 月出生）的个体和相对年龄较大（1 月至 2 月出生）的对照组。在 297,840 人的总样本中，6,528 人在儿童时期被诊断为多动症。这 4 项结果是在 15 至 23 岁时测量的。我们检查了年轻相对年龄和 ADHD 对长期结果的主要、附加和交互影响。

结果

在没有 ADHD 的个体中，年轻的相对年龄与抑郁症风险增加（比值比 [OR] = 1.14 [95% CI =1.09–1.20]）、SUD（OR = 1.14 [1.09–1.20]）和低教育程度相关成就 (OR = 1.17 [1.14–1.20])，但不是犯罪 (OR = 1.00 [0.98–1.03])。在患有 ADHD 的个体中，年轻的相对年龄与 SUD 风险增加（OR = 1.23 [1.01–1.50]）和低教育成就（OR = 1.12 [1.00–0.26]；CI 包括 1）相关，但与抑郁或犯罪无关（OR = 0.88 [0.73–1.07] 和 OR = 0.89 [0.79–1.01] 分别）。年轻的相对年龄和 ADHD 之间出现了抑郁症的相互作用（OR = 0.78 [0.64–0.95]）。

结论

我们观察到相对年龄效应增加了支持对入学年龄采取更灵活方法的证据，并强调了在评估儿童 ADHD 症状期间仔细进行年龄匹配比较的重要性。