健康与遗传心理学研究室知识库

    青少年饮酒是一种常见的现象，也经常与内外化问题同时发生。虽然以往研究关注了酒精使用障碍及一些精神疾病之间的关联，然而，对于一般的饮酒行为关注较少。由于青春期是毕生发展的关键时期，一般的饮酒行为也会对青少年产生影响，因此非常需要展开对一般饮酒行为的研究。此外，以往研究虽然发现了酒精使用与内外化问题存在关联，二者的共生往往会对青少年产生更严重的危害。但是二者关联的方向还不确定，究竟是饮酒行为导致了内外化问题，还是内外化问题导致饮酒行为，或是二者由共同的因素所影响，目前还没有针对我国青少年的研究结论。因此，本研究采用系统化的研究方法，分别从纵向研究，孟德尔随机化以及双生子遗传环境研究的角度，探讨了中国青少年酒精使用与内外化行为可能的关系路径。
    研究一采用纵向追踪数据，探讨在两个时间点上酒精使用与内外化行为的相互预测关系，结果发现，对于中国青少年而言，酒精使用可能是导致违纪行为和抑郁的前因变量，而抑郁是导致青少年酒精使用的前因变量。饮酒数量和饮酒愿望与内外化行为存在较强的关联，而饮酒频率与内外化问题的关系较弱。在本研究关注的五个内外化问题中，焦虑与青少年的饮酒行为不存在任何纵向预测关系。此外，酒精使用与内外化行为的关系模式也存在性别差异，对于男生而言，二者的关联更强。
    研究二使用一种新颖的研究范式，即孟德尔随机化，以ALDH2基因作为酒精使用的工具变量，探讨其与内外化行为之间的因果关系，结果发现，青少年酒精使用可能是攻击行为和注意问题的原因，而不是违纪行为，焦虑及抑郁的原因。此外，我们也进行了中介分析，证明ALDH2基因对攻击行为和注意问题的影响只通过酒精使用行为产生。
    研究三使用双生子研究设计，探讨酒精使用与内外化行为是否具有共同的遗传和环境基础。就外化行为而言，酒精使用与其均存在显著的遗传相关，具有较为一致的遗传基础，基因可以解释其大部分表型相关。而内化问题与酒精使用行为的表型相关较低，二者的遗传基础较不一致。
总的来看，本研究发现酒精使用与外化行为具有密切的关系，相互影响，并受到共同的遗传环境影响，而与内化问题的关系较为薄弱。酒精使用与内外化问题的关系也存在性别差异。

    Adolescent alcohol use is a common phenomenon and it often co-occur with internalizing and externalizing problems. Although previous studies have focused on the relationship between alcohol use disorders and some mental illnesses, there is less concern for general drinking behavior. Since adolescence is a critical period of lifelong development, the general drinking behavior will also have an impact on adolescents. Therefore, research on general drinking behavior is very necessary. In addition, although previous studies have found that there is a link between alcohol use and internalizing and externalizing problems, the direction of the relationship between the two is still uncertain. It is whether drinking behavior leads to internalizing or externalizing problems, vice versa, or both of them are affected by a third common factor. There is currently no research conclusion for Chinese youth.Therefore, this study adopts a systematic research method,  from the perspective  of longitudinal  research, Mendelian  randomization,and behavioral genetics approach to explore the possible relationship between alcohol use and internalizing and externalizing problems  of Chinese adolescents.
    Study I used longitudinal data to explore the mutual predictive relationship  between  alcohol  use  and  internalizing  and  externalizing problems at two time points. It was found that for Chinese adolescents,alcohol use may be an antecedent variable leading to delinquency and depression, and depression is an antecedent variable that leads to alcohol use.There was a strong correlation between the amount of alcohol consumed and the desire for drinking and externalizing/internalizing problems, while the relationship between drinking frequency and internalizing and externalizing problems are weak. In the five externalizing/internalizing problems that this study focuses on, there is no longitudinal relationship between anxiety and adolescent drinking behavior. In addition, there are gender differences in the relationship between alcohol use and externalizing/internalizing problems,for boys, the relationship is stronger than girls.
    Study 2 used a novel approach, Mendelian randomization, using the ALDH2 gene as an instrumental variable for alcohol use, to explore its causal relationship with internalzing and externalizing behaviors. Alcohol use was positively associated with all 3 externalizing and 2 internalizing problems,and the ALDH2 polymorphism had a significant effect on alcohol use.Aggression and attention problems were also significantly affected by the ALDH2 polymorphism, whereas no significant association was observed between the ALDH2 polymorphism and delinquency, anxiety, or depression.The results suggest that alcohol use is a cause of adolescent aggression and attention problems but not adolescent delinquency, anxiety, or depression.
    Study 3 used twin studies to determine if there was a common genetic and environmental basis for alcohol use and externalizing/internalizing problems. As far as the externalization behavior is concerned, there is a significant genetic correlation with alcohol use, and genes can explain most of their phenotypic correlations. However, the internalizing problems are less related to the phenotype of alcohol use behavior and the genetic basis of the two is more inconsistent.
    Overall, this stu即found that alcohol use and externalizing problems are closely related to each other, affect each other, and are affected by a common genetic and environment factors, whereas the relationship with internalizing problems is weak. There is also a gender difference in the relationship  between  alcohol  use  and  internalizing  and  externalizing problems.