Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
Psychol Med. 2013 Jan;43(1):197-207. doi: 10.1017/S0033291712001067. Epub 2012 Aug 16.
Attention deficit hyperactivity disorder (ADHD) frequently persists into adulthood. Family and twin studies delineate a disorder with strong genetic influences among children and adolescents based on parent- and teacher-reported data but little is known about the genetic and environmental contribution to DSM-IV ADHD symptoms in adulthood. We therefore aimed to investigate the impact of genetic and environmental influences on the inattentive and hyperactive-impulsive symptoms of ADHD in adults.
Twin methods were applied to self-reported assessments of ADHD symptoms from a large population-based Swedish twin study that included data from 15 198 Swedish male and female twins aged 20 to 46 years.
The broad heritability [i.e., A + D, where A is an additive genetic factor and D (dominance) a non-additive genetic factor] was 37% (A = 11%, D = 26%) for inattention and 38% (A = 18%, D = 20%) for hyperactivity-impulsivity. The results also indicate that 52% of the phenotypic correlation between inattention and hyperactivity-impulsivity (r = 0.43) was explained by genetic influences whereas the remaining part of the covariance was explained by non-shared environmental influences. These results were replicated across age strata.
Our findings of moderate broad heritability estimates are consistent with previous literature on self-rated ADHD symptoms in older children, adolescents and adults and retrospective reports of self-rated childhood ADHD by adults but differ from studies of younger children with informant ratings. Future research needs to clarify whether our data indicate a true decrease in the heritability of ADHD in adults compared to children, or whether this relates to the use of self-ratings in contrast to informant data.
注意力缺陷多动障碍（ADHD）在成年后经常持续存在。基于父母和教师报告的数据，家庭和双胞胎研究描绘了一种在儿童和青少年中具有强烈遗传影响的疾病，但对于成年后 DSM-IV ADHD 症状的遗传和环境贡献知之甚少。因此，我们旨在研究遗传和环境因素对成年 ADHD 患者注意力不集中和多动冲动症状的影响。
采用双生子方法，对一项大型基于人群的瑞典双胞胎研究中的自我报告 ADHD 症状进行评估，该研究包括 15198 名年龄在 20 至 46 岁的瑞典男性和女性双胞胎的数据。
广泛的遗传度[即 A + D，其中 A 是加性遗传因素，D（显性）是非加性遗传因素]为注意力不集中的 37%（A = 11%，D = 26%），多动冲动的 38%（A = 18%，D = 20%）。结果还表明，注意力不集中和多动冲动之间的表型相关（r = 0.43）的 52%由遗传因素解释，而剩余的协方差部分由非共享环境因素解释。这些结果在不同年龄组中得到了复制。
我们发现中度广泛遗传度估计值与之前关于年龄较大的儿童、青少年和成年人自我报告的 ADHD 症状以及成年人对自我报告的儿童期 ADHD 的回顾性报告的文献一致，但与使用知情者报告的年幼儿童的研究不同。未来的研究需要澄清我们的数据是否表明与儿童相比，成年人 ADHD 的遗传度确实降低，或者这是否与使用自我报告而不是知情者数据有关。
