儿童品行问题与注意缺陷多动行为问题相互关系的双生子研究

Examining the genetic relationship of attention deficit and hyperactivity disorder and conduct disorder in a population-based twin sample

目的研究遗传因素、共享环境因素和非共享环境因素在儿童注意缺陷多动行为问题和品行问题相互关系中的作用。方法采用困难和长处量表中的父母评定的注意缺陷多动（HYPER）和品行问题（COND）分量表分作为定量表型，对西南双生子库中的140对双生子，采用表型的单因素和二因素结构方程模型，基于模型的似然值和拟合度寻找最优模型，分析遗传因素和环境因素的影响。结果（1）同卵双生子注意缺陷多动行为问题与品行问题的相关性（r=0．55）明显高于异卵双生子（r=0．12）；（2）注意缺陷多动行为问题与品行问题的表型相关性为0．44（P=0．00）；（3）儿童注意缺陷多动行为问题与品行问题的相关性主要由遗传因素导致，遗传因素在品行问题与注意缺陷多动行为问题表型相关性中的贡献占70％，非共享环境因素占30％。结论遗传因素对注意缺陷多动行为问题和品行问题的发生具有重要作用，遗传因素包括单纯影响注意缺陷多动行为问题的遗传因素、单纯影响品行障碍的遗传因素和对二者同时发生作用的遗传因素。大部分作用于注意缺陷多动行为问题的环境因素不会导致品行问题的发生。

Objective To examine three possible causes of the relationship between attention deficit and hyperactivity disorder （HYPER） and conduct disorder （COND） ： additive genetic factors （A）, common environmental factors （C） and individual-specific environmental factors （E）. Methods 140 pairs of twins from the Southwestern China Twin Registry were examined with the parent-rated Strength and difficulties questionnaire （SDQ）. The cross-twin within-variable, within-twin cross-variable and cross-twin cross- variable correlations were calculated. Using structural equation modelling, bivariate models were fitted. The best fitting model was chosen based on likelihood and parsimony. Results The correlation between attention deficit and hyperactivity behavior and conduct behavior in monozygotic twins （ r = 0. 55） was significantly higher than that in dyzygotic twins （ r = 0.12）. The observed phenotypic correlation between HYPER and COND was 0.44 （P = 0.00）, with genetic factors accounting for about 70% of the observed correlation. Conclusions In children, three different genetic factors may exist： one that solely affects the liability to hyperactivity behaviour, one that has only an effect on conduct behaviour and one that influences both hyperactivity and conduct behaviour. Our restdts suggests that most of the environmental factors that increase the risk of hyperactivity behaviour do not influence conduct behaviour and vice versa.