遗传与环境因素对儿童内向行为影响的双生子研究

目的 利用双生子设计的定量遗传分析方法探讨遗传因素与环境因素对于儿童内向行为的影响.方法 使用Achenbach儿童行为评定量表家长版本调查了189对成都地区6～16岁双生子的内向行为,采用Holzinger公式计算遗传度,家长评定家庭亲密度和适应性量表、一般健康问卷调查特定环境因素.结果 (1)儿童内向行为遗传度为0.54,年龄、性别与其相关.(2)家庭实际适应性、父母心理健康情况与儿童的内向行为显著相关(r=-0.213,0.250,0.309;Ps＜0.001),母亲心理健康状况为其危险因素(OR=2.483,P=0.008).结论 遗传因素和环境因素对儿童的内向行为均有影响,年龄和性别与遗传度相关,影响儿童内向行为的环境因素包括家庭功能和父母的心理健康水平.     

注意缺陷多动障碍与品行障碍共病机制的双生子研究

目的 研究遗传因素和环境因素的相互作用对于注意缺陷多动障碍和品行障碍共病的影响.方法 利用已经建立的西南地区双生子随访登记系统,采用定量行为遗传学研究方法,用《困难和长处量表》父母评定的注意缺陷多动和品行问题分量表分作为定量表型,收集140对6～16岁双生子的临床资料,构建双生子行为表型的单因素和二因素结构方程模型,分析变量内双生子间、变量间双生子内以及变量间双生子间的相关性,基于模型的似然值和拟合度寻找最优模型,阐明遗传因素、共享的环境因素以及非共享的环境因素对于注意缺陷多动障碍和品行障碍共病的影响.结果 注意缺陷多动和品行问题的表型相关性为0.44(95% CI:0.09～0.27),其中遗传因素在二者总的表型相关性中占70%,非共享的环境因素占30%.对相关变量构建二因素结构方程模型并进行多个模型拟合,对寻找出的最优模型分析发现,注意缺陷多动和品行问题遗传相关性为0.76(95% CI:0.31～1),而个体特异性环境相关性为0.28(95% CI:0.02～0.51).结论 儿童存在3种不同的遗传因素影响注意缺陷多动障碍和品行障碍的发生,即单纯影响注意缺陷多动障碍的遗传因素、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.本研究结果提示大部分作用于注意缺陷多动障碍的环境因素不会导致品行障碍的发生,即二者缺乏共同的环境因素.     

中国双生子登记系统进展

目的分别在中国北方和南方、城市和农村地区建立四个以人群为基础的双生子登记系统；应用本双生子登记系统，选择成年双生子进行详细调查，开展心脑血管疾病及其相关性状的遗传流行病学研究。方法双生子的登记主要依靠卫生防疫三级保健网络进行覆盖。对于参与详细调查的双生子的募集，不同地区因地制宜．采用不同的方式。结果目前登记系统已登记7423对双生子，并对其中1613对双生子进行详细调查和体检。系统在基线登记的基础上，还建立了一个包含579对双生子的队列。已进行的研究包括成年双生子心脑血管疾病相关中间表型研究、心理学研究、青少年生长发育研究等。结论中国双生子登记系统是目前中国首个以人群为基础的双生子登记系统，它已成为医学和科学研究的一项重要的国际和国内资源。     

10—16岁儿童少年行为问题的双生子研究

目的:调查遗传因素和环境因素对10-16岁儿童少年行为问题的影响程度,为儿童少年行为问题的防治提供依据.方法:采用多级随机抽样的方法选取64对双生子,使用Achenbach儿童行为量表评定行为问题,估算遗传因素及环境因素对儿童少年行为问题的影响程度.结果:10-16岁儿童少年总的行为问题的遗传度为0.33,共享环境的影响程度为0.57,非共享环境的影响程度为0.10.其中退缩行为、躯体主诉、注意缺陷及违纪行为的遗传度超过0.6,共享环境对焦虑/抑郁、社交问题及攻击行为的影响程度在0.41～0.64之间.结论:遗传因素和环境因素对儿童少年的行为问题均有影响,但环境因素影响程度更大,尤其是共享环境因素.     

遗传因素和环境因素对儿童亲社会行为影响的双生子研究

目的 应用双生子设计的定量遗传分析方法探讨遗传因素与环境因素对于儿童亲社会行为的影响.方法 使用长处与困难问卷(strengths and difficulties questionnaire,SDQ)家长版本调查了147对成都地区6～16岁双生子的亲社会行为,使用SPSS13.0统计软件、Mx软件进行描述性统计分析、差异性分析、相关分析及遗传分析.结果 (1)除<11岁组外,女性亲社会因子得分显著高于男性(P3<0.05);(2)共享环境因素对儿童亲社会行为的贡献为0.48(95%CI:0.09～0.73),遗传因素的贡献为0.27(95%CI:0～0.66),个体特异性环境因素的贡献为0.25(95%CI:0.18～0.35);(3)女性、家庭实际及理想的亲密度和适应性越好者亲社会行为越好(r:0.17～0.29),而存在孕产期异常情况者、家长管教态度越不一致者亲社会行为越不良(r:-0.16～-0.28).结论 遗传因素和环境因素对儿童的亲社会行为均有影响,年龄和性别与儿童亲社会行为的遗传度相关,影响儿童亲社会行为的环境因素包括家庭功能和教养环境.     

儿童青少年智力的双生子研究

目的 应用双生子法探讨遗传和环境因素对儿童青少年智力影响.方法 采用中国修订版-韦氏儿童智力量表评定6～16岁333对双生子的智力特点.应用结构方程模型分析遗传和环境因素对智力的影响.结果 6～16岁儿童青少年的总智商(intelligence quotient,IQ)遗传度为0.43,其中言语智商(verbal intelligence quotient,VIQ)遗传度为0.37,而遗传因素对操作智商(performance intelligence quotient,PIQ)影响甚小.10～16岁的青少年智力遗传度大于6～9岁的儿童(IQ:0.82 vs 0.00,VIQ:0.80 vs 0.00,PIQ:0.51 vs 0.00).男性的言语智商(0.47)受遗传影响大于女性(0.05);而在男性和女性中,操作智商均主要受共享环境的影响.结论 在儿童青少年时期,总智商和言语智商有中度的遗传度,而共享环境因素对操作智商的影响更大;但智商总分及言语智商和操作智商分测试分在年龄较大的青少年的遗传度都明显高于年龄较小的儿童.     

儿童青少年智力的双生子研究

目的 应用双生子法探讨遗传和环境因素对儿童青少年智力影响.方法 采用中国修订版-韦氏儿童智力量表评定6～16岁333对双生子的智力特点.应用结构方程模型分析遗传和环境因素对智力的影响.结果 6～16岁儿童青少年的总智商(intelligence quotient,IQ)遗传度为0.43,其中言语智商(verbal intelligence quotient,VIQ)遗传度为0.37,而遗传因素对操作智商(performance intelligence quotient,PIQ)影响甚小.10～16岁的青少年智力遗传度大于6～9岁的儿童(IQ:0.82 vs 0.00,VIQ:0.80 vs 0.00,PIQ:0.51 vs 0.00).男性的言语智商(0.47)受遗传影响大于女性(0.05);而在男性和女性中,操作智商均主要受共享环境的影响.结论 在儿童青少年时期,总智商和言语智商有中度的遗传度,而共享环境因素对操作智商的影响更大;但智商总分及言语智商和操作智商分测试分在年龄较大的青少年的遗传度都明显高于年龄较小的儿童.     

儿童青少年智力的双生子研究

目的 应用双生子法探讨遗传和环境因素对儿童青少年智力影响.方法 采用中国修订版-韦氏儿童智力量表评定6～16岁333对双生子的智力特点.应用结构方程模型分析遗传和环境因素对智力的影响.结果 6～16岁儿童青少年的总智商(intelligence quotient,IQ)遗传度为0.43,其中言语智商(verbal intelligence quotient,VIQ)遗传度为0.37,而遗传因素对操作智商(performance intelligence quotient,PIQ)影响甚小.10～16岁的青少年智力遗传度大于6～9岁的儿童(IQ:0.82 vs 0.00,VIQ:0.80 vs 0.00,PIQ:0.51 vs 0.00).男性的言语智商(0.47)受遗传影响大于女性(0.05);而在男性和女性中,操作智商均主要受共享环境的影响.结论 在儿童青少年时期,总智商和言语智商有中度的遗传度,而共享环境因素对操作智商的影响更大;但智商总分及言语智商和操作智商分测试分在年龄较大的青少年的遗传度都明显高于年龄较小的儿童.     

儿童青少年智力的双生子研究

目的 应用双生子法探讨遗传和环境因素对儿童青少年智力影响.方法 采用中国修订版-韦氏儿童智力量表评定6～16岁333对双生子的智力特点.应用结构方程模型分析遗传和环境因素对智力的影响.结果 6～16岁儿童青少年的总智商(intelligence quotient,IQ)遗传度为0.43,其中言语智商(verbal intelligence quotient,VIQ)遗传度为0.37,而遗传因素对操作智商(performance intelligence quotient,PIQ)影响甚小.10～16岁的青少年智力遗传度大于6～9岁的儿童(IQ:0.82 vs 0.00,VIQ:0.80 vs 0.00,PIQ:0.51 vs 0.00).男性的言语智商(0.47)受遗传影响大于女性(0.05);而在男性和女性中,操作智商均主要受共享环境的影响.结论 在儿童青少年时期,总智商和言语智商有中度的遗传度,而共享环境因素对操作智商的影响更大;但智商总分及言语智商和操作智商分测试分在年龄较大的青少年的遗传度都明显高于年龄较小的儿童.     

儿童青少年智力的双生子研究

目的 应用双生子法探讨遗传和环境因素对儿童青少年智力影响.方法 采用中国修订版-韦氏儿童智力量表评定6～16岁333对双生子的智力特点.应用结构方程模型分析遗传和环境因素对智力的影响.结果 6～16岁儿童青少年的总智商(intelligence quotient,IQ)遗传度为0.43,其中言语智商(verbal intelligence quotient,VIQ)遗传度为0.37,而遗传因素对操作智商(performance intelligence quotient,PIQ)影响甚小.10～16岁的青少年智力遗传度大于6～9岁的儿童(IQ:0.82 vs 0.00,VIQ:0.80 vs 0.00,PIQ:0.51 vs 0.00).男性的言语智商(0.47)受遗传影响大于女性(0.05);而在男性和女性中,操作智商均主要受共享环境的影响.结论 在儿童青少年时期,总智商和言语智商有中度的遗传度,而共享环境因素对操作智商的影响更大;但智商总分及言语智商和操作智商分测试分在年龄较大的青少年的遗传度都明显高于年龄较小的儿童.     

A common genetic factor explains the association between psychopathic personality and antisocial behavior

BACKGROUND: Both psychopathic personality traits and antisocial behavior are influenced by genetic as well as environmental factors. However, little is known about how genetic and environmental factors contribute to the associations between the psychopathic personality traits and antisocial behavior. METHOD: Data were drawn from a longitudinal population-based twin sample including all 1480 twin pairs born in Sweden between May 1985 and December 1986. The twins responded to mailed self-report questionnaires at two occasions: 1999 (twins 13-14 years old), and 2002 (twins 16-17 years old). RESULTS: A common genetic factor loaded substantially on both psychopathic personality traits and antisocial behavior, whereas a common shared environmental factor loaded exclusively on antisocial behavior. CONCLUSIONS: The genetic overlap between psychopathic personality traits and antisocial behavior may reflect a genetic vulnerability to externalizing psychopathology. The finding of shared environmental influences only in antisocial behavior suggests an etiological distinction between psychopathic personality dimensions and antisocial behavior. Knowledge about temperamental correlates to antisocial behavior is important for identification of susceptibility genes, as well as for possible prevention through identification of at-risk children early in life.     

Psychopathic personality traits: heritability and genetic overlap with internalizing and externalizing psychopathology

BACKGROUND: Little research has examined genetic and environmental contributions to psychopathic personality traits. Additionally, no studies have examined etiological connections between psychopathic traits and the broad psychopathological domains of internalizing (mood and anxiety) and externalizing (antisocial behavior, substance abuse). The current study was designed to fill these gaps in the literature. METHOD: Participants were 626 pairs of 17-year-old male and female twins from the community. Psychopathic traits were indexed using scores on the Multidimensional Personality Questionnaire (MPQ). Symptoms of internalizing and externalizing psychopathology were obtained via structured clinical interviews. Structural equation modeling was used to estimate genetic and environmental influences on psychopathic personality traits as well as the degree of genetic overlap between these traits and composites of internalizing and externalizing. RESULTS: Twin analyses revealed significant genetic influence on distinct psychopathic traits (Fearless Dominance and Impulsive Antisociality). Moreover, Fearless Dominance was associated with reduced genetic risk for internalizing psychopathology, and Impulsive Antisociality was associated with increased genetic risk for externalizing psychopathology. CONCLUSIONS: These results indicate that different psychopathic traits as measured by the MPQ show distinct genetically based relations with broad dimensions of DSM psychopathology.     

The phenotypic and genetic relationships among measures of cognitive ability,temperament, and scholastic achievement

The covariance among measures of cognitive ability, temperament, and scholastic achievement was examined in a subsample of 326 (89 Monozygotic, 74 Dizygotic) twins drawn from the Western Reserve Twin Project. Both phenotypic and behavioral genetic models were fit to the data. Univariate analyses indicate significant genetic influences on cognitive, achievement, and temperament variables. Common environmental influences also affected cognition and achievement but not temperament. Multivariate analyses indicate that both genetic and common environmental influences contribute to the covariance among all three variables. Cognition and achievement are highly genetically correlated. In contrast, achievement and temperament are highly correlated for common environmentality, while cognition and temperament are not.     

Genetic differences in alcohol sensitivity and the inheritance of alcoholism risk

BACKGROUND: Substantial evidence exists for an important genetic contribution to alcohol dependence risk in women and men. It has been suggested that genetically determined differences in alcohol sensitivity may represent one pathway by which an increase in alcohol dependence risk occurs. METHODS: Telephone interview follow-up data were obtained on twins from male, female and unlike-sex twin pairs who had participated in an alcohol challenge study in 1979-81, as well as other pairs from the same Australian twin panel surveyed by mail in 1980-82. RESULTS: At follow-up, alcohol challenge men did not differ from other male twins from the same age cohort on measures of lifetime psychopathology or drinking habits; but alcohol challenge omen were on average heavier drinkers than other women. A composite alcohol sensitivity measure, combining subjective intoxication and increase in body-sway after alcohol challenge in 1979-81, exhibited high heritability (60 %). Parental alcoholism history was weakly associated with decreased alcohol sensitivity in women, but not after adjustment for baseline drinking history, or in men. High alcohol sensitivity in men was associated with substantially reduced alcohol dependence risk (OR = 0.05, 95% CI 0.01-0.39). Furthermore, significantly decreased (i.e. low) alcohol sensitivity was observed in non-alcoholic males whose MZ co-twin had a history of alcohol dependence, compared to other non-alcoholics. These associations remained significant in conservative analyses that controlled for respondents' alcohol consumption levels and alcohol problems in 1979-81. CONCLUSIONS: Men (but not women) at increased genetic risk of alcohol dependence (assessed by MZ co-twin's history of alcohol dependence) exhibited reduced alcohol sensitivity. Associations with parental alcoholism were inconsistent.     

The Genetic Relationship Between Social Cognition and Conduct Problems

Studies of children and adolescents with conduct problems suggest both genetic and environmental influences on population variance. Any genetic influence is likely to be complex and to act via mediating attributes of personality or cognitive style. One potential mediating attribute is social cognitive ability, as conduct problems have been shown to be associated with deficient social cognitive skills. The current investigation has examined the correlation between conduct problems and social cognition and has investigated the genetic and environmental influences on these measures and their covariation using a twin design. A population-based sample of twins aged 5-17 was used to examine the genetic relationship between conduct problems and social cognition using parent-report questionnaires. Conduct problems and social cognition were found to be highly correlated and to share common genetic influences that accounted for about half the covariation in scores. Each phenotype was subject to its own environmental influences that were not shared.     

Environmental Factors in Obsessive-Compulsive Behavior: Evidence from Discordant and Concordant Monozygotic Twins

To investigate environmental factors that protect against or exacerbate obsessive-compulsive (OC) symptoms, we selected 25 monozygotic (MZ) twin pairs discordant, 17 MZ twin pairs concordant high and 34 MZ pairs concordant low on OC symptoms from a large longitudinal Dutch sample of adult twin pairs and their family members, applying stringent criteria for OC symptomatology. Data were collected on psychopathology, family structure, health, lifestyle, birth complications and life events. Unique environmental factors were studied using within-discordant MZ pair comparisons, whereas between-concordant MZ pair comparisons were used to study environmental factors that are shared by the twins of an MZ pair. The high-scoring MZ twins of the discordant group reported more life events (especially sexual abuse) than their low-scoring twin-siblings. The between-pair comparisons showed lower birth weight in the discordant MZ pairs than in the concordant MZ pairs. Further, the concordant high MZ pairs as well as their spouses had a lower educational level than the two other groups. On scale scores of anxious-depression, neuroticism, and somatic complaints, concordant high MZ pairs showed highest scores, and the discordant MZ pairs scored intermediate, except for neuroticism, on which the high-scoring twins of discordant MZ pairs were equal to the concordant high pairs. Discordance on psychological scale scores between the concordant MZ pairs was evident from 1991 onward, and within the discordant MZ pairs from 1997 onward, confirming previous reports of an association of early-onset OC symptoms with higher genetic load. Parent scores of OC symptoms and anxious-depression suggested intermediate genetic load in the discordant MZ group. In conclusion, this study reports on both unique and shared environmental factors associated with OC symptomatology. Whether these factors operate in addition to or in interaction with genetic disposition is to be elucidated in future studies. Edited by Tatiana Foroud.     

Familial influence on offspring gambling: a cognitive mechanism for transmission of gambling behavior in families

BACKGROUND: The problem-gambling literature has identified a range of individual, cognitive, behavioral and emotional factors as playing important roles in the development, maintenance and treatment of problem gambling. However, familial factors have often been neglected. The current study aims to investigate the possible influence of parental factors on offspring gambling behavior. METHOD: A total of 189 families (546 individuals) completed several questionnaires including the South Oaks Gambling Screen (SOGS) and the Gambling Related Cognition Scale (GRCS). The relationships were examined using Pearson product-moment correlations and structural equation modeling (SEM) analyses. RESULTS: Results showed that generally parents' (especially fathers') gambling cognitions and gambling behaviors positively correlated with offspring gambling behaviors and cognitions. However, SEM analyses showed that although parental gambling behavior was directly related to offspring gambling behavior, parental cognitions were not related to offspring gambling behavior directly but indirectly via offspring cognitions. CONCLUSION: The findings show that the influence of parental gambling cognition on offspring gambling behavior is indirect and via offspring cognitions. The results suggest a possible cognitive mechanism of transmission of gambling behavior in the family from one generation to the next.     

A Study of Genetic and Environmental Influences on Maternal and Paternal CBCL Syndrome Scores in a Large Sample of 3-Year-Old Dutch Twins

Background. There is increasing evidence that behavioral problems are common in very young children, yet little is known about the etiology of individual differences in these problems. It is unclear to what degree environmental and genetic factors influence the development of early child psychopathology. In this paper, we focus on the following issues. Firstly, to what degree do genetic and environmental factors influence variation in behavioral problems? Secondly, to what degree are these underlying etiological factors moderated by sex and informant? We investigate these issues by analyzing Child Behavior Checklist (CBCL) data on 9689 3-year-old twin pairs.Methods. Rater Bias and Psychometric Models were fitted to CBCL/2-3 data obtained from mothers and fathers to determine the genetic and environmental contributions to the five CBCL syndromes:aggressive, oppositional, overactive, withdrawn, and anxious/depressed behavior.Results. Parental ratings are influenced by aspects of the child's behavior that are experienced in the same way by both parents and by aspects of the child's behavior that are experienced uniquely by each parent. There is evidence for high genetic contributions to all CBCL syndromes. Shared and non-shared environmental influences play significant roles as well. One exception is overactive behavior, which is influenced by genetic and non-shared environmental influences only.Conclusions. Variation in behavior problems in the very young shows high heritability.Individual raters offer unique perspectives that can have an impact on estimates of problem behavior and genetic architecture. Therefore, multi-informant approaches in the assessment of the very young will be useful to clinicians and researchers alike.     

Exploring the Association Between Well-Being and Psychopathology in Adolescents

Promotion of mental well-being and prevention of emotional and behavioral problems are suggested to go hand in hand. The present study examined the association between subjective well-being (SWB) and psychopathology and investigated the etiology of this association in a large population-based cohort study of adolescent twins (n = 9,136) and their non-twin siblings (n = 1,474) aged 12–20 years. Phenotypic, genetic, and environmental correlations between SWB and psychopathology were obtained from multivariate genetic modeling conditional on sex. An SWB factor score was used based on measures of subjective happiness, satisfaction with life, and quality of life. Psychopathology was obtained from all syndrome and broad-band scales of the Dutch version of the ASEBA Youth Self Report. Males reported significantly higher levels of SWB than females. Females reported significantly more internalizing problems while males report significantly higher levels of externalizing behavior. In both sexes, significant negative associations were found between SWB and psychopathology, with the strongest associations seen for SWB and the YSR syndrome scale anxious/depression behavior. The observed associations were primarily explained by genetic correlations while non-shared environmental influences were mainly domain specific. The genetic liability to lower levels of SWB are indicative of a genetic liability to higher levels of psychopathology, suggesting that it might be feasible to screen for emotional and behavioral problems before clear signs are present by screening on indices of subjective well-being.