A Life Course Study of Genetic and Environmental Influences on Work Incapacity.

Work incapacity is a major public health challenge and an economic burden to both society and individuals. Understanding the underlying causes is becoming ever more relevant as many countries face an aging workforce. We examined stability and change in genetic and environmental factors influencing work incapacity from age 18 until retirement, and sex differences in these effects.

Pre-pregnancy mental distress and musculoskeletal pain and sickness absence during pregnancy - a twin cohort study.

Sickness absence (SA) among pregnant women is high. The aim of this study was to examine whether factors known to predict SA in general also predict SA during pregnancy by estimating the association between prior mental distress and musculoskeletal pain and SA during pregnancy, and to assess the influence of familial (genetic and shared environmental) factors. In this prospective cohort study, data from 2076 female twins born 1967-79 who participated in a questionnaire study in 1998 were linked to register data on SA and childbirth during the years 1998-2008.

Sex differences in genetic and environmental contributions to alcohol consumption from early adolescence to young adulthood.

Aims: To estimate genetic and environmental contributions to alcohol consumption from early adolescence to young adulthood, and test whether gender moderates these effects.

Design: Longitudinal twin cohort design.

Setting: Population-based sample from Norway.

Common Etiological Sources of Anxiety, Depression, and Somatic Complaints in Adolescents: A Multiple Rater twin Study.

Somatic complaints in children and adolescents may be considered part of a broader spectrum of internalizing disorders that include anxiety and depression. Previous research on the topic has focused mainly on the relationship between anxiety and depression without investigating how common somatic symptoms relate to an underlying factor and its etiology. Based on the classical twin design with monozygotic and dizygotic twins reared together, our study aimed to explore the extent to which the covariation between three phenotypes in adolescent girls and boys can be represented by a latent internalizing factor, with a focus on both common and specific etiological sources.

Genetic and environmental influences on adolescents' smoking involvement: a multi-informant twin study.

Studying monozygotic and dizygotic adolescent twin pairs of both sexes reared together, the present study examined the extent to which the variance in smoking involvement is attributable to genetic and environmental effects, and to what extent there are sex differences in the etiology. Questionnaire data on how often the adolescent had ever smoked tobacco was collected from a population-based twin sample consisting of seven national birth cohorts (ages 12-18), their mothers, and their fathers (N = 1,394 families). The data was analyzed with multivariate genetic modeling, using a multi-informant design.

Genetic and environmental causes of variation in adolescent anxiety symptoms: a multiple-rater twin study.

Heritability estimates for adolescent anxiety vary across studies, partly depending on who is rating the symptoms. The goal of our study was to estimate genetic and environmental influences using a multi-informant design with responses from a population-based sample of adolescent twins, their mothers and their fathers (N=1394 families). Results from multivariate biometrical modeling indicated quantitative, but no qualitative sex differences in etiology.

Predictors of depressive symptoms among resettled unaccompanied refugee minors.

This study investigated the level and predictors of depressive symptoms among unaccompanied refugee minors after resettlement in Norway. Participants (N = 414) were resettled in 26 municipalities from all regions of the country. The average length of resettlement time was 3.