Paul Lichtenstein

..However, other explanations such as personality characteristics influencing how experiences with parents are interpreted or circumstances in adult life that affect the recall of experiences could not be ruled out...

..The contribution of hereditary factors to the causation of sporadic cancer is unclear. Studies of twins make it possible to estimate the overall contribution of inherited genes to the development of malignant diseases...

..These results indicate that both heritable factors as well as environmental factors such as trauma, vicarious learning, and/or negative information are important for differences in fearfulness and phobias--at least in children...

..Further, genes and environmental factors of importance in childhood were important also in early adolescence...

..Our objective was to investigate whether fetal growth and birth weight affect the risk of asthma in childhood, controlling for gestational age (GA), and shared (familial) environment and genetic factors...

..The increased odds ratio between offspring of sisters was independent of maternal risk factors for preterm birth, suggesting that the relative importance of maternal effects is not explained by these well-known risk factors...

..It is hypothesized that associations found between birth weight and subsequent risk of type-2 diabetes are due to inherited genes affecting both fetal growth and metabolism of insulin...

..Women with schizophrenia are at increased risk for adverse pregnancy outcomes. It is not known whether offspring born to fathers with schizophrenia also have an increased risk...

..Life-course persistent criminality has been proposed to have a partly biological etiology; our results agree with a stronger biological effect (i.e., de novo mutations) on persistent violent offending...

..Together, these findings emphasize the importance of genetically informed studies in family research and the role of the environment and interpersonal relationships in promoting and improving mental health...

..Poor fetal nutrition has been suggested to explain this association. Our objective was to determine whether genetic factors contribute to the association between low birth weight and subsequent risk of type 2 diabetes...

..Studies have found associations between low birth weight and increased risks of cardiovascular diseases in adulthood. However, these associations could be due to confounding by genetic or socioeconomic factors...

..Here we investigate the extent to which genetic variants in the oxytocin receptor gene (OXTR) are associated with pair-bonding and related social behaviors in humans...

..Little is known of the onset of breast cancer in high-risk populations. We investigated the risk of breast cancer in twin sisters and in the contralateral breast taking family history into consideration...

..We aimed to assess genetic and environmental contributions to liability for schizophrenia, bipolar disorder, and their comorbidity...

..The results showed that this association was best explained by evocative genotype-environment correlation...

..Results indicate that physical activity is associated with a reduced risk of mortality not due to genetic selection. This finding supports a causal link between physical activity and mortality...

..An abundance of evidence has firmly established the familial aggregation of schizophrenia. The aim of this study was to examine how age at onset, parental characteristics and season of birth modify the familiality in schizophrenia...

..4), appeared to result from both phenotypic assortment and social homogamy, but had only minor effect on variance components. Finally, we found significant gender differences in the etiology of violent crime...

..Population-based studies of the heritability of other neuropsychiatric disorders and comorbidities among them have also been sparse. The authors sought to address both of these issues...

..The aim of the current study was to explore the links between both paternal and grandpaternal age with respect to the risk of schizophrenia in a large, national register-based cohort...

..This suggests that previously reported differences in caretaking between mothers and fathers also are reflected in differences in why parenting is associated with externalizing behavior in offspring...

..Advancing paternal age has been reported as a risk factor for neurodevelopmental disorders...

..We motivate our problem with real questions from psychiatric epidemiology and demonstrate how different substantive issues of comorbidity between two diseases can be put into the analytical framework...

..78). No association was found for prostate cancer. We conclude that age is an important effect modifier of cancer risk associated with obesity and that obesity and overweight in young adult life may affect cancer risk also later in life...

..The aim of this study was to assess genetic links between the extreme and the subthreshold range of ADHD symptoms...

..Epidemiological studies have suggested a familial aggregation. This study aimed to quantify the genetic influence (i.e. the heritability) on dystocia...

..This study examined how interpersonal relationships, specifically marital quality and adequacy of social support, are associated with depressive symptoms among women...

..To determine whether low birth weight increases the risk of attention-deficit/hyperactivity disorder (ADHD) in childhood and early adolescence...

..To investigate annual prevalence of disability pension (DP) from 1992 to 2007 and associations with sociodemographic factors in 1992...

..Prenatal factors such as prenatal psychological stress might influence the development of childhood asthma...

..Because the malignancies are dependent on UV radiation, we did separate analyses for sun-covered and sun-exposed sites...

..The hypothesis that the aggressive pathway is genetically mediated was supported in girls, whereas the hypothesis that the nonaggressive pathway is environmentally dependent was supported in boys...

..In particular, we describe recent efforts to screen all twins born between 1959 and 1985, and young twin pairs when they turn 9 and 12 years of age. For these studies, we present initial frequencies of common conditions and exposures...

..It suggests that aggression in children evokes negative parenting, which in turn influences adolescent antisocial behavior. The mechanism proposed by these findings is consistent with evocative gene-environment correlation...

..This study first considers age and cohort explanations for age-related changes in mean values and variance in self-rated health. Second, it evaluates the contributions of genes and environments to self-rated health measured longitudinally...

..This study was undertaken to disentangle the maternal genetic, fetal genetic, and environmental effects for the risk of having small-for-gestational-age (SGA) offspring...

..94, 95% CI 0.84-1.05). In conclusion, we found reduced fertility in patients with schizophrenia and among their offspring that was not compensated by higher parental or sibling fertility...

..However, the results were sensitive to issues related to power, minor effects of the genes, ethnic differences and the complex mechanism underlying obesity...

..There is a long-standing belief that creativity is coupled with psychopathology...

..Numerous studies have shown that higher body mass index (BMI) is associated with higher mortality. We investigated the extent to which this association might be explained by genetic factors...

..Our results indicated that hyperactivity/impulsivity, but not inattention, is an important early predictor for early-onset substance use, and a shared genetic susceptibility is suggested to explain this association...

..In conclusion, our results show heritability to be a major susceptibility factor for symptomatic gallstone disease, consistent with results from previous, much smaller studies...

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..To assess the relative risk for amyotrophic lateral sclerosis (ALS) in families of ALS patients...

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..In this article we describe the sample, data collections, and measures used. In addition, we provide some key findings from the study, focusing on antisocial behavior, criminality, and psychopathic personality...

..Thus, the model provides evidence for etiologic generality and etiologic specificity for the stability of psychopathic personality between mid- and late adolescence...

..Finally, nonshared environmental influences were the primary contributor to both individual reports and the overlap of spouse reports, an interesting deviation from findings of behavior genetic studies of other types of relationships...

..The aim in this study was to investigate the direction of effects between psychopathic personality and antisocial behaviour, and to investigate the genetic and environmental contribution to this association...

..4-0.9). Genetic factors account for more than half of the liability of preeclampsia, and maternal genes contribute more than fetal genes. We suggest that the couple effect is due to a genetic interaction between mother and father...

..Method A cohort of 11 162 same-sexed Swedish twins born between 1906 and 1958 was used in order to investigate the risk of developing Type 2 diabetes between and within twin pairs by utilizing random effects linear models...

..In the following, we will summarize the content of the database, describe for the first time recent data collection efforts and review some of the principal findings that have come from the Registry...

..We aimed to examine the association between symptomatic GD and overweight (body mass index, BMI, 25-30 kg m(-2)), obesity (BMI > 30 kg m(-2)), alcohol, smoking and smoke-free tobacco by analysing a large twin population...

..The association between low birthweight and schizophrenia is partly a function of reduced fetal growth. Fetal growth restriction seems to be associated with risk of schizophrenia independently of familial factors...

..These data may be valuable for planning and interpreting genetic studies of schizophrenia...

..These results suggest an association between a single gene and pair-bonding behavior in humans, and indicate that the well characterized influence of AVP on pair-bonding in voles may be of relevance also for humans...

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..To study the association between method of attempted suicide and risk of subsequent successful suicide...

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..This study does not indicate any negative effects from dental amalgam on physical or mental health or memory functions in the general population over 50 years of age...

..Attention deficit-hyperactivity disorder (ADHD) is a common disorder that has been associated with criminal behavior in some studies. Pharmacologic treatment is available for ADHD and may reduce the risk of criminality...

..Within-twin-pair analysis provides a unique opportunity to investigate whether factors shared within twin pairs influence the association...

..There is a dearth of long term, follow-up studies after sex reassignment...

..This could be important for studies of potential susceptibility genes for these diseases...

..However, many studies have not been able to replicate findings of association between specific polymorphisms and diastolic and systolic blood pressure...

..One explanation for this paradox could be that socioeconomic status moderates the influence of genetic and environmental effects on antisocial behavior...

..The aim of this study was to examine genetic influences contributing to the development of hyperactive-impulsive symptoms and inattentive symptoms of ADHD from childhood to adolescence...

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..The authors propose that this latent psychopathic personality factor is a meaningful target for future etiological research...

..We examined if mothers' smoking during pregnancy (SDP) is associated with long-term impairment in offspring stress coping and the causal mechanism behind a possible link...

..CONCLUSIONS: The genetic stability highlights the importance of the continuing search for genes and endophenotypes of ADHD...

..The importance of physical activity for breast cancer risk seems to depend on birth cohort. The association may be limited to normal-weight postmenopausal women and overweight premenopausal women...

..We have prospectively investigated maternal serum levels of IGF-I, IGF-II, and the main binding protein insulin-like growth factor binding protein 3 (IGFBP-3) in women with and without preeclampsia...

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..We did not find a genetic component to endometrial cancer. Our results confirm that environmental factors are the most important, especially physical activity, parity, and weight in young and middle age...

..By investigating the association within twin pairs discordant for disease, the influence of genetic and early environmental factors is substantially reduced...

..These data indicate that neither adult anthropometry nor age at menarche is in the causal pathway between intrauterine preeclampsia exposure and the reduced risk of breast cancer...

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..We undertook a case-control study in twins discordant for acute myocardial infarction (AMI)...

..Self-rated health has been shown to be a predictor for future health status and mortality. The purpose of this study was to investigate age-group and sex differences in genetic and environmental sources of variation for self-rated health...

..We found no evidence of an inverse association between either occupational or leisure time physical activity and risk of renal cell cancer in this prospective cohort...

..Further elucidation of this association would be valuable from both etiologic and public health perspectives...

..CONCLUSION: We conclude that at least from the parents' point of view the behaviour problems in their children may be related to maturity...

..Thus, there is no evidence for a paternal effect on monozygotic twinning, suggesting that the gene(s) increasing the liability for division of the embryo are expressed in the mother and not in the fertilised egg...

..5; 95% CI 0.7-18.5). The results give some support to the hypothesis that the fetal environment influences adult breast cancer risk...

..When studying risk factors for teenage childbearing, it is recommended to include life style and socio-economic variables as well as information about family history of teenage childbearing. Twin Research (2000) 3, 23-27...

..In efforts to identify women with elevated risk of developing pre-eclampsia during pregnancy, a question about family history of pre-eclampsia should be included...

..We conclude that genetic and individual specific effects are important for recurrent headaches of migrainous and nonmigrainous types in prepubescent children, and that different genetic etiologies might exist for boys and girls...

..In our illustration the models will account for maternal or foetal genetic effects, environmental effects, or a combination of these and we show how these effects can be readily estimated using family data...

..When interpreting the findings, the very brief measure of sexual problem behavior and low statistical power, precluding the analysis of possible coinheritance with other symptoms or disorders, should be borne in mind...

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..Shared and childhood environments were equally important in colorectal cancer and melanoma, whereas no childhood effect was observed for lung cancer...

..We investigated these polymorphisms in Swedish twins by merging the Swedish Twin Registry with the Hospital Discharge and Causes of Death Registries for gallstone disease-related diagnoses...

..The aim of this study was to investigate the genetic effects on leisure-time physical activity using data from the Swedish Twin Registry...

..However, the causes of this psychiatric ill-health are mostly unknown...

..Studies have found associations between birth weight and risk of atopic eczema or allergic rhinitis (AR), although this could be due to confounding...

..The results suggest that the increased risk for circulatory diseases related to pregnancy is mainly confined to a few days around delivery...

..To investigate the impact of coexistent psychiatric morbidity on risk of suicide after a suicide attempt...

..To study the long-term relationship between symptoms of Attention Deficit Hyperactivity Disorder and the developing self-esteem in a population-based sample of twins...