Biomedical subjects

Espen Røysamb

Publications and source records attributed to Espen Røysamb.

At least 19 recordsLinked to original sources

PubMed2006

Genetic and environmental influences on dimensional representations of DSM-IV cluster C personality disorders: a population-based multivariate twin study.

BACKGROUND: The DSM-IV cluster C Axis II disorders include avoidant (AVPD), dependent (DEPD) and obsessive-compulsive (OCPD) personality disorders. We aimed to estimate the genetic and environmental influences on dimensional representations of these disorders and examine the validity of the cluster C construct by determining to what extent common familial factors influence the individual PDs. METHOD: PDs were assessed using the Structured Interview for DSM-IV Personality (SIDP-IV) in a sample of 1386 young adult twin pairs from the Norwegian Institute of Public Health Twin Panel (NIPHTP). A single-factor independent pathway multivariate model was applied to the number of endorsed criteria for the three cluster C disorders, using the statistical modeling program Mx. RESULTS: The best-fitting model included genetic and unique environmental factors only, and equated parameters for males and females. Heritability ranged from 27% to 35%. The proportion of genetic variance explained by a common factor was 83, 48 and 15% respectively for AVPD, DEPD and OCPD. Common genetic and environmental factors accounted for 54% and 64% respectively of the variance in AVPD and DEPD but only 11% of the variance in OCPD. CONCLUSION: Cluster C PDs are moderately heritable. No evidence was found for shared environmental or sex effects. Common genetic and individual environmental factors account for a substantial proportion of the variance in AVPD and DEPD. However, OCPD appears to be largely etiologically distinct from the other two PDs. The results do not support the validity of the DSM-IV cluster C construct in its present form.

Adult↗

PubMed2006

Recurrent otitis media and tonsillitis: common disease predisposition.

OBJECTIVE: To estimate the relative contribution of genetic and environmental effects to the association between recurrent otitis media and recurrent tonsillitis. METHODS: Self-report questionnaire data from a population-based cohort of 9479 Norwegian twins born from 1967 to 1979. Recurrent otitis media and recurrent tonsillitis were main outcome measures. Structural equation modelling was used to fit alternative biometric models to the twin data and to estimate the relative contribution of genetic and environmental effects to the association between otitis media and tonsillitis. RESULTS: The lifetime prevalence was 11.7% (95% CI: 11.0-12.3) for recurrent tonsillitis and 11.2% (95% CI 10.5-11.9) for recurrent otitis media. Tetrachoric correlations were greater in monozygotic than in dizygotic twins in both males and females. A model specifying additive genetic effects and individual environmental effects for otitis media and tonsillitis and non-additive genetic effects for tonsillitis yielded the best fit. There was no evidence for sex differences in the genetic source or magnitude of the genetic effects. There was a substantial overlap in genetic factors influencing variation in liability to otitis media and tonsillitis. CONCLUSION: Common genetic factors contribute substantially to comorbidity between recurrent otitis media and recurrent tonsillitis.

Environment↗

PubMed2006

Risk factors for completed suicide in veterans of peacekeeping: repatriation, negative life events, and marital status.

This psychological autopsy study focused on suicide risk factors in veterans of peacekeeping, specifically, a representative sample of Norwegian peacekeepers. A multivariate analysis yielded three dimensions with a unique impact on suicide risk: Involuntary repatriation from peacekeeping service, negative life-events before peacekeeping and marital status. In accordance with previous research into suicidal processes, repatriation probably reflects an event causing severe damage to peacekeepers' self-esteem, which combined with vulnerability and lack of protection could increase suicide risk. Preventive measures should focus on careful personnel selection and follow-up of repatriated individuals.

Adult↗

PubMed2006

Adolescent adjustment and well-being: effects of parental divorce and distress.

This study investigates the long-term effects of parental divorce on adolescent psychological adjustment and well-being, and to what extent the effects are accounted for by parental psychological distress. Data were collected among 8,984 Norwegian adolescents (13-19 years) and their parents. Outcome variables were symptoms of anxiety and depression, subjective well-being, and three areas of school problems. Parental divorce was found to be associated with both higher mean levels and larger variances in adolescent problems. Divorce and parental distress contributed independently to adolescent distress, supporting the notion of "double exposure" effects. The prevalence of adolescents with substantial distress symptoms was 14% among those with non-distressed non-divorced parents and 30% among those with divorced and distressed parents. In general effects remained when controlling for demographic factors. Long-term effects of divorce on symptoms of anxiety and depression were stronger among girls than among boys.

Adaptation, Psychological↗

PubMed2006

Multivariate genetic analysis of sex limitation and G x E interaction.

Sex-limited expression of genetic or environmental factors occurs in two basic forms. First, the effects of a factor may be larger on one sex than on another, which is known as scalar sex limitation. Second, some factors may have an effect on one sex but not on the other, which is called nonscalar sex limitation. In the classical twin study, scalar sex-limited effects cause same-sex male and same-sex female twin correlations to differ. Nonscalar sex-limited effects would cause the correlations between opposite-sex pairs of relatives to be lower than would be expected from the correlations between relatives of the same sex. One approach to modeling such effects is to allow the genetic correlation between opposite-sex dizygotic twins to be less than one-half; another is to allow the common environment correlation for opposite-sex pairs to be less than unity. Extension of this approach to the multivariate case is not straightforward. Direct extension of the Cholesky decomposition such that each Cholesky factor is allowed to correlate less than one-half in opposite-sex pairs yields a model where the order of the variables can change the goodness-of-fit of the model. It is shown that similar problems exist with a variety of multivariate and longitudinal models, and in a variety of models of genotype x environment interaction. Several solutions to these problems are described.

Female↗

PubMed2005

The reliability of self-reported childhood otitis media by adults.

OBJECTIVE: To estimate reliability of retrospective questionnaire data on childhood recurrent otitis media, and to identify factors influencing inconsistency in self-report. METHODS: Retrospective questionnaire data from a population-based sample of 4430 Norwegian twins who participated in two questionnaire surveys, 6 years apart, containing identical questions on otitis media. Main outcome measure was individual consistency in reporting of otitis media. The tetrachoric correlation and Cohen's Kappa were used to measure reliability. Inconsistent and consistent responders were compared on medical history and mental distress. The use of twin data made it possible to test whether inconsistent responders represent a group with intermediate levels of otitis media severity. RESULTS: The test-retest tetrachoric correlation was 0.82 and Kappa was 0.53. Inconsistency in response was not associated with mental distress, but related to reported number of otitis media episodes per year, use of medical services and history of ear surgery. CONCLUSION: Retrospective self-reported otitis media is a relatively reliable measure. The study suggests that reporting inconsistency is likely to be associated with less severe disease. The finding that reporting pattern is related to disease severity is in accordance with the proposed need for a uniform agreement on the definition of the term "recurrent otitis media" for research purposes.

Adult↗

PubMed2005

A comparison of genetic and environmental variance structures for asthma, hay fever and eczema with symptoms of the same diseases: a study of Norwegian twins.

BACKGROUND: We compared patterns of genetic and environmental influences on variation in liability for asthma, hay fever and eczema with those for symptoms of the same diseases, and determined how common sets of genes and environmental factors contribute to the relationship between diseases and symptoms among Norwegian twins. METHODS: Analyses were based on self-reported asthma, hay fever and eczema and symptoms of the same diseases among 3334 pairs of Norwegian twins aged 18-35 years. Structural equation modelling was conducted to estimate the genetic and environmental variance structures. RESULTS: For all diseases the concordances and the twin correlations were higher among monozygotic than among dizygotic twins. The results of the modelling confirmed that genetic effects were substantial for the diseases, and were more moderate for symptoms. The phenotypic correlation between disease and symptom was 0.67 for asthma and wheeze (a/w), 0.64 for hay fever and sneeze (hf/s), and 0.54 for eczema and itch (e/i). Decomposition of these correlations into genetic (G) and environmental (E) pathways revealed that G = 0.48 and E = 0.19 for a/w, G = 0.40 and E = 0.24 for hf/s, and G = 0.34 and E = 0.20 for e/i. For the diseases, the specific sources of genetic variance accounted for more variation than the specific environmental variance. Variance decomposition revealed that specific sources of variance were primarily explained by genetic effects for diseases and by environmental influences for symptoms. CONCLUSIONS: Genetic effects account for greater variation in reported diseases than symptoms. Co-occurrence of diseases and symptoms is mainly explained by genetic effects common to both phenotypes, but non-shared environment is also important.

Adult↗

PubMed2005

Adolescents with a childhood experience of parental divorce: a longitudinal study of mental health and adjustment.

**This is a prospective Norwegian study of a group of adolescents with an experience of parental divorce or separation (n=413) and a comparison group without this experience (n=1758). Mean age at T1 was 14.4 years and mean age at T2 was 18.4 years. Parental divorce was prospectively associated with a relative change in anxiety and depression, subjective well-being, self-esteem, and school problems. Considering boys separately, parental divorce was prospectively associated only with school problems. Among the girls, divorce was prospectively associated with all variables. The effect of divorce on relative change was partially mediated by paternal absence.

Adaptation, Psychological↗

PubMed2005

Social class, gender and psychosocial predictors for early sexual debut among 16 year olds in Oslo.

BACKGROUND: Variations in early sexual debut among 16 year olds were investigated by social level variables, parental occupation, gender, ethnicity, family structure, family functioning, and individual level variables, future aspirations, academic and social self-perception, and depressed moods. METHODS: The variations in sexual debut were investigated by examining proportions of 16 year olds reporting their first intercourse before age 16. The data were collected by self-reporting questionnaires administered to in-school-youth, in Oslo. Multivariate logistic regression analyses were used to test for associations. Gender interactions with all variables were tested. RESULTS: Overall, 25% reported early debut. Independent effect of social class on differences in proportions in early sexual debut were found. Gender interaction with social class, ethnicity and academic self-perception as they associate to proportions having had early sexual debut, were found. For girls the pattern of social class differences was linear and the highest proportions were found among working classes. For boys the pattern was U-shaped and upper managerial and manual working class youth had similar, higher proportions of early debutants. High scores of parental monitoring, future aspirations and academic self-concept and low scores of depressed moods, are protective factors. While high social self-perception is positively associated with early debut for both genders. CONCLUSION: Early sexual debut varies according to social class, following gender-specific patterns, among 16 year olds in Oslo. The negative association between early debut and academic self-perception are for boys less influenced by other social and individual level factors, than for girls.

Adolescent↗

PubMed2005

Heritability of recurrent tonsillitis.

OBJECTIVE: To estimate the relative contribution of genetic and environmental effects on the variance in the liability of recurrent tonsillitis. DESIGN: Retrospective questionnaire data from a population-based cohort. SETTING: Population-based data from Norway. PARTICIPANTS: A total of 9479 Norwegian twins born between January 1, 1967, and December 31, 1979, identified through the Medical Birth Registry of Norway. Main Outcome Measure Recurrent tonsillitis. RESULTS: The lifetime prevalence of recurrent tonsillitis was 11.7% (95% confidence interval, 11.0%-12.3%), with a significant predominance of female cases. The tetrachoric correlations for monozygotic twins were 0.71 for males and 0.60 for females. For dizygotic twins, the correlations were 0.12 for males, 0.14 for females, and 0.24 for dizygotic pairs of opposite sex. Structural equation modeling indicated that genetic effects explained 62% of the variation in the liability of recurrent tonsillitis. The remaining variance was attributed to individual environmental effects. There was no evidence of sex-specific genetic effects on the liability of recurrent tonsillitis. CONCLUSION: There is evidence for a substantial genetic predisposition for recurrent tonsillitis.

Adult↗

PubMed2005

Relationships between health domains and sense of coherence: a two-year cross-lagged study in patients with chronic illness.

The latent structure of Sense of Coherence (SOC) and its relationship with three domains of health (body function, activity and participation) were studied in a cohort of people with chronic illness (n = 771) over a period of 2 years. A structural equation approach with cross-lagged and synchronous models was applied to each combination of SOC and domain of health. Over the 2-year period SOC had enhanced body function and participation. Conversely, levels of activities as well as body function had contributed to SOC 2 years later. Significant synchronous effects were found that indicated the presence of reciprocal causation between SOC and all three domains of health. These findings challenge existing SOC theory and suggest that SOC can be considered a relevant outcome variable in chronic illness care.

Activities of Daily Living↗

PubMed2005

Ethnic group, acculturation, and psychiatric problems in young immigrants.

BACKGROUND: The goal of this study was to investigate the effects of ethnic origin and acculturation factors on psychiatric problems among immigrant adolescents. One aim was to examine variations in psychiatric problems according to gender and immigrant generation level. Another aim was to explore ethnic group differences in psychiatric problems and acculturation risk and protective factors. Finally, we examined the potential mediating effect of acculturation in the relationship between ethnic origin and psychiatric symptoms. METHOD: Questionnaire data were collected from 1275 immigrant 10th graders with 11 different ethnic origins. Psychiatric problems were measured by the Strength and Difficulty Questionnaire. Acculturation risk factors involved perceived discrimination and ethnic identity crisis. Protective factors were family values, host and ethnic culture competence. RESULTS: First-generation girls and second-generation boys were identified as particularly vulnerable to psychiatric problems. There was significant variation in psychiatric problems and acculturation between ethnic groups. There was substantial ethnic group-level correlation between emotional and conduct problems, and between discrimination and peer problems. Otherwise, a differentiated pattern of high-scoring ethnic groups emerged across the various symptom and acculturation indices. ANOVAs yielded unique effects on each symptom category of both ethnic group and the acculturation risk and protective factors, undermining the notion of a mediating effect of acculturation. CONCLUSIONS: There is a complex pattern of adaptation in cultural context and idiosyncratic relationships between distinct psychiatric symptom groups and socio-cultural factors. Information about the differentiated vulnerability of gender, generation, and ethnic groups to psychiatric morbidity is important to identify groups at special risk, and to produce interventions that are tailored to their needs. Future studies should examine how cultural factors contribute both to resilience and to an increased vulnerability to psychiatric problems.

Acculturation↗

PubMed2005

Perceived difficulty in the theory of planned behaviour: perceived behavioural control or affective attitude?

A study was conducted to explore (a) the dimensional structure of perceived behavioural control (PBC), (b) the conceptual basis of perceived difficulty items, and (c) how PBC components and instrumental and affective attitudes, respectively, relate to intention and behaviour. The material stemmed from a two-wave study of Norwegian graduate students (N = 227 for the prediction of intention and N = 110 for the prediction of behaviour). Data were analysed using confirmatory factor analysis (CFA) and multiple regression by the application of structural equation modelling (SEM). CFA suggested that PBC could be conceived of as consisting of three separate but interrelated factors (perceived control, perceived confidence and perceived difficulty), or as two separate but interrelated factors representing self-efficacy (measured by perceived difficulty and perceived confidence or by just perceived confidence) and perceived control. However, the perceived difficulty items also overlapped substantially with affective attitude. Perceived confidence was a strong predictor of exercise intention but not of recycling intention. Perceived control, however, was a strong predictor of recycling intention but not exercise intention. Affective attitudes but not instrumental attitudes were identified as substantial predictors of intentions. The findings suggest that at least under some circumstances it may be inadequate to measure PBC by means of perceived difficulty. One possible consequence may be that the role of PBC as a predictor of intention is somewhat overestimated, whereas the role of (affective) attitude may be similarly underestimated.

Adult↗

PubMed2005

Subjective wellbeing and sleep problems: a bivariate twin study.

The relationship between subjective wellbeing (SWB) and self-reported sleep problems was investigated in a cohort of Norwegian twins aged 18 to 31 years. Questionnaire data from 8045 same- and opposite-sex twins were analyzed using structural equation modeling to explore the relative effects of genetic and environmental influences on phenotypic variance and covariance. Special attention was paid to sex-specific effects. The correlation between the phenotypes was estimated to be -.43. Univariate analyses indicated considerable genetic influences for both SWB and sleep problems, for male and female twins alike. The best fitting bivariate model specified additive genetic and individual environmental factors for both phenotypes, and nonadditive genetic effects for sleep problems, with no sex-specific effects. Genetic and environmental effects accounted for 60% and 40% of the phenotypic correlation, respectively. Additive genetic factors affecting the two phenotypes were correlated (-.85), suggesting that part of the genetic effects that positively influence SWB also protect against sleep problems. In conclusion, the results indicate considerable overlap in genetic etiology for SWB and sleep problems, for males and females alike.

Adolescent↗

PubMed2004

Genetic and environmental influences on the association between smoking and panic attacks in females: a population-based twin study.

BACKGROUND: Clinical and epidemiological studies have reported an association between lifetime cigarette-smoking and panic attacks. Several explanations for this relationship have been proposed, mostly focusing on direct causal pathways. The objective of this study was to investigate a hypothesis of shared vulnerability by examining whether panic attacks and cigarette-smoking share genetic or environmental liability factors. METHOD: Questionnaire data on 3172 female-female twins (1409 complete pairs), aged 18-31 years, from a population-based Norwegian twin registry, were used to calculate the correlation between genetic factors and the correlation between environmental factors that influence lifetime measures of panic attacks and daily smoking. RESULTS: The best-fitting biometrical twin model suggested that genetic factors influencing panic and smoking were uncorrelated. Shared or familial environmental factors were perfectly correlated, and accounted for 75 % of the association between the phenotypes. The correlation between individual environmental factors influencing the phenotypes was 0.25 (0.07-0.44). In the full model, the genetic correlation was 0.17 (0.00-1.00), and genetic and shared environmental factors respectively accounted for 18 % and 61 % of the co-variance between panic and smoking. CONCLUSION: The results suggest that panic attacks and lifetime smoking have few or no genetic liability factors in common. The shared environmental factors that influence the two phenotypes are identical. Liability to panic attacks in females appears to be more influenced by shared environmental factors than previously indicated by univariate studies.

Adolescent↗

PubMed2004

Mental health, life stress and social support among young Norwegian adolescents with immigrant and host national background.

The first aim of the study was to investigate differences in level of mental health, life stress and social support among adolescents with immigrant and domestic background. A second aim was to identify culture group and gender specific sources of risk and protective factors and their relation to mental health. Questionnaire data were collected from 633 students, aged 13, in Oslo, Norway. Immigrant adolescents reported higher level of psychological distress and lower social support than host students. Of the four gender-culture groups, immigrant boys reported the highest level of problems, with a 28% prevalence of anxiety/depression. There were no significant differences in prevalence among the girls. Specific patterns of relationships between life stress, support, and mental health were found across gender and culture. The results were discussed within a framework of culture differences in values and gender role expectancies, underscoring the importance of studying each gender/culture group separately.

Acculturation↗

PubMed2004

Temperament in adults--reliability, stability, and factor structure of the EAS Temperament Survey.

We assessed the factor structure and psychometric properties of the Emotionality, Activity, and Sociability (EAS) Temperament Survey (Buss & Plomin, 1984) for adults using a longitudinal sample of adult women. The stability estimates of the EAS instrument were assessed over a period of 3 years. The results indicated an acceptable fit for the basic theoretical EAS model, implying that the scale is functioning satisfactory. However, the results also suggest that the measure could be improved. Across time, latent stability factors explained within-scale covariances. Both latent stability factors and time-specific factors accounted for cross-sectional covariances between subscales. Additional research is warranted to guide the further development of the EAS model.

Adult↗

PubMed2004

Otitis media: genetic factors and sex differences.

Although genetic factors are recognised as major contributors to otitis media, the presence of sex differences in heritability needs clarification. The aim of this study was to estimate the relative contribution of genetic and environmental effects in otitis media liability with particular focus on sex differences. Data from a cohort of Norwegian twins born between 1967 and 1979 with repeated measures on recurrent childhood otitis media were analysed. Altogether the sample included 4247 twin pairs. The tetrachoric correlations for monozygotic twins were .71 and .65 for males and females respectively. In dizygotic twins the correlations were .35 and .25 for males and females, respectively, and was.34 in opposite sexed pairs. The contribution of genetic and environmental effects was analyzed using structural equation modeling. The best fitting model showed that additive genetic effects explained 72% and 61% of the variance in males and females, respectively. The remaining variance was attributed to individual environmental effects. A model specifying equal heritability estimates for males and females yielded an almost equivalent fit. We found substantial genetic effects for liability to otitis media. There is no evidence that different sets of genes influence liability in males and females, but there may be sex differences in the relative importance of genetic effects.

Cohort Studies↗