Low genetic effect and age-specific family effect for symptoms of anxiety and depression in nuclear families, halfsibs and twins

Health, health behaviors, and health dissimilarities predict divorce: results from the HUNT study

Background

Poor health and health behaviors are associated with divorce. This study investigates the degree to which six health indicators and health behaviors among husbands and wives are prospectively related to divorce, and whether spousal similarities in these factors are related to a reduced risk of marital dissolution. Theoretically, a reduced risk is possible, because spousal similarity can help the couple’s adaptive processes.

Methods

The data come from a general population sample (19,827 couples) and 15 years of follow-up data on marital dissolution. The following characteristics were investigated: Poor subjective health, obesity, heavy drinking, mental distress, lack of exercise, and smoking. Associations between these characteristics among husbands and wives and later divorce were investigated with Cox proportional hazards regression analyses.

Results

All the investigated characteristics except obesity were associated with marital dissolution. Moreover, spousal similarities in four of these characteristics (heavy drinking, mental distress, no exercise, and smoking) reduced the risk of divorce, compared to the combined main effects of husbands and wives. Nevertheless, couples concordant in these health issues still had higher risks of divorce than couples without these characteristics.

Conclusion

Couples with similar health and health behavior are at a lower risk of divorce than are couples who are dissimilar in health. Health differences may thus be seen as vulnerabilities or stressors, supporting a health mismatch hypothesis. This study demonstrates that people who are similar to each other are more likely to stay together. Harmonizing partners’ health behaviors may be a target in divorce prevention.

Mental distress predicts divorce over 16 years: the HUNT study

Background

The association between mental distress and divorce is well established in the literature. Explanations are commonly classified within two different frameworks; social selection (mentally distressed people are selected out of marriage) and social causation (divorce causes mental distress). Despite a relatively large body of literature on this subject, selection effects are somewhat less studied, and research based on data from both spouses is scarce. The purpose of the present study is to investigate selection effects both at the individual level and the couple level.

Methods

The current study is based on couple-level data from a Norwegian representative sample including 20,233 couples. Long-term selection effects were tested for by means of Cox proportional hazard models, using mental distress in both partners at baseline as predictors of divorce the next 16 years. Three identical sets of analyses were run. The first included the total sample, whereas the second and third excluded couples who divorced within the first 4 or 8 years after baseline, respectively. An interaction term between mental distress in husband and in wife was specified and tested.

Results

Hazard of divorce was significantly higher in couples with one mentally distressed partner than in couples with no mental distress in all analyses. There was also a significant interaction effect showing that the hazard of divorce for couples with two mentally distressed partners was higher than for couples with one mentally distressed partner, but lower than what could be expected from the combined main effects of two mentally distressed partners.

Conclusions

Our results suggest that mentally distressed individuals are selected out of marriage. We also found support for a couple-level effect in which spouse similarity in mental distress to a certain degree seems to protect against divorce.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-015-1662-0) contains supplementary material, which is available to authorized users.

More mental health problems after divorce in couples with high pre-divorce alcohol consumption than in other divorced couples: results from the HUNT-study

Background

Divorce is associated with mental health problems, and heavy drinking is related to higher risk of divorce. Less is known about the effects of divorce in couples where one or both drinks heavily. There are, however, reasons to expect different consequences of divorce in heavy risk using couples compared to other couples. Spouses of abusers may experience the divorce as a relief, whereas abusers may find it extra difficult to be left single. The aim of the study is to compare the effect of divorce on mental health in heavy drinking couples to the effect in couples who drink less.

Methods

Registry data were matched with data from the Nord-Trøndelag Health Study (HUNT 1 (T1) and 2 (T2)), enabling longitudinal analyses of approximately 11,000 couples. Interaction terms between 1) alcohol use on T1 and divorce between T1 and T2 (11 year time lag), and 2) alcohol use on T1 and time since divorce at T2 for all divorced couples were tested to examine changes in mental health between T1 and T2 for a) spouses of high-risk compared to low-risk users, and b) high-risk compared to low-risk users themselves. Data were analyzed using multivariate analysis of variance.

Results

There was a general effect of divorce on change in mental health between T1 and T2. We observed a significantly stronger worsening in mental health in female high-risk users and their spouses than in divorced low-risk users and their spouses. The results also suggest that the strain after divorce lasts longer in women with a high alcohol consumption and their spouses.

Conclusions

Divorce seems to affect couples where one or both drink heavily more than couples with a low consumption. Also there was some evidence of a slower healing of mental health problems after divorce in alcohol exposed couples than in other couples. The results only reached significance for female high consumers and their spouses, but due to limited statistical power, safe conclusions about gender specific effects cannot be drawn.

Childhood respiratory symptoms and mental health problems: the role of intergenerational smoking

OBJECTIVE

The aim of this study was to investigate the potential role of youth smoking, parental cigarette smoking and parental anxiety/depressive disorders in the relationship between respiratory symptoms and mental health problems among youth.

WORKING HYPOTHESIS

Adjusting for both parental smoking and parental anxiety/depressive disorders in the association between respiratory symptoms and mental health problems among young persons will significantly reduce the strength of the observed relationship.

STUDY DESIGN

Prospective cohort study. PATIENT-SUBJECT SELECTION: Data were drawn from a school-based sample of 1709 young persons in Oregon.

METHODOLOGY

Physical and mental health data were collected on youth.

RESULTS

Respiratory symptoms were associated with significantly increased odds of mental health problems among youth. After adjusting for youth smoking, the relationship between respiratory symptoms and depressive disorders was no longer statistically significant. The relationships between respiratory symptoms and anxiety and depressive disorders were no longer significant after adjusting for parental smoking. Parental anxiety/depressive disorders did not appear to influence these relationships.

CONCLUSIONS

These results provide initial evidence that exposure to parental smoking may play a role in the observed co-occurrence of respiratory and mental health problems in youth, and youths' own smoking appears to influence the link with depressive disorders, but not anxiety disorders.

History of Norwegian psychiatry

Psychiatry as a professional and scientific enterprise developed in Norway in the middle of the 19th century. During the last part of this century, four state asylums were erected, followed by several county asylums during the first part of the 20th century. From the 1870 s, institutions for private care were established, usually in the vicinity of the asylums. During the middle of the 19th century, psychiatry in Norway was influenced by "moral treatment", but during the end of the century somatic ideas prevailed. After the Second World War, Norwegian psychiatry was influenced by Dutch and British social psychiatry, followed by American psychoanalytic-oriented psychiatry during the 1960-70s. Since the 1980s, the climate changed, with more emphasis on classification and drug therapy. The new American DSM-III also influenced Norwegian psychiatry, and cognitive-behavioral therapies became more prevalent. Norwegian psychiatric research has during the last few decades been characterized by epidemiological studies, clinical follow-ups and twin research.

Norwegian Twin Registers and Norwegian Twin Studies — An Overview

The Norwegian Twin Registers include several sets of population-based sub-registers, and covers twin pairs born between 1895 and today. Except for the missing birth years 1960 to 1967, the register is almost complete. Most of the register contains information about both same-sexed and opposite-sexed twin pairs, except for twin pairs born between 1946 and 1960, where only same-sexed twins are registered. In a substantial part of the register, information about zygosity is obtained, mainly by a mailed questionnaire and in some cases supported by DNA testing. These are the birth years 1915 to 1960 and the birth years 1967 to 1979. Zygosity information is further obtained in the different twin studies derived from the twin register. In 1990 the whole register was made available in a computerized form. Several twin studies have been derived from the different parts of the register. In this article, studies from the two earliest parts of the register are reviewed and grouped by recruitment specifics. Finally, future plans for the register and twin studies are discussed.

Comparing the biological and cultural inheritance of personality and social attitudes in the Virginia 30 000 study of twins and their relatives

Measures of four dimensions of personality (Psychoticism, Extraversion, Neuroticism, and Lie scores) and six aspects of social attitudes (to sex, taxation, militarism, politics, religion and a general conservatism scale) were obtained by mailed questionnaire from 29 691 US subjects including adult twins (n = 14 761) their parents (n = 2360), their spouses (n = 4391), siblings (n = 3184) and adult children (n = 4800). After correction for the average effects of age, sex and source of sample, familial correlations were computed for 80 distinct biological and social relationships. The data allow for the estimation of the additive and non-additive effects of genes, assortative mating, vertical cultural inheritance and other non-parental effects of the shared environment on differences in personality and social attitudes. The interaction of genetic and environmental effects with sex may also be analyzed. Model-fitting analyses show that personality and social attitude measures differ markedly in major features of family resemblance. Additive and dominant genetic effects contribute to differences in both personality and attitudes, but the effects of the family environment, including vertical cultural transmission from parent to child, are much more marked for social attitudes than for personality. There is substantial assortative mating for social attitudes and almost none for personality. The causes of family resemblance depend significantly on sex for almost every variable studied. These findings clarify and extend the more tentative findings derived from previous twin, family and adoption studies.

Alcohol use and mental distress as predictors of non-response in a general population health survey: the HUNT study

PURPOSE

To investigate to what degree alcohol use and mental distress are associated with non-response in a population-based health study.

METHODS

From 1995 to 1997, 91,488 persons were invited to take part in a health study at Nord-Trøndelag, Norway, and the response rate was 69.2%. Demographics were available for everyone. Survey answers from a previous survey were available for most of the participants and a majority of non-participants. In addition, the survey responses from spouses and children of the invitees were used to predict participation in the aforementioned study. Crude and adjusted ORs for a number of predictors, among these alcohol consumption and mental distress, are reported.

RESULTS

Both heavy drinkers (OR = 1.27) and abstainers (OR = 1.64) had a higher probability of dropping out in comparison to people who usually do not drink. High levels of mental distress (OR = 1.84) also predicted attrition.

CONCLUSION

Alcohol use and mental distress are moderately associated with non-response, though probably not a major cause, as controlling for other variables weakened the associations. Nevertheless, the moderate but clear underrepresentation at the crude level of people with high alcohol consumption, abstainers and people with poor mental health should be taken into consideration when interpreting results from health surveys.

Strong genetic correlation between interview-assessed internalizing disorders and a brief self-report symptom scale

Self-report scales for symptoms of anxiety and depression are frequently used for screening and research purposes. A moderate phenotypic association between disorders measured by diagnostic interviews and symptoms of anxiety and depression measured by self-report scales has been shown, but little is known about the overlap in these phenotypes' genetic and environmental variance. In the present study, we used twin modeling to identify common genetic and environmental liabilities underlying the phenotypic association between the self-report Symptom Checklist-5 (SCL-5) and lifetime internalizing disorders derived from the Composite International Diagnostic Interview (CIDI). The sample consisted of 7,992 young adult twins from the Norwegian Institute of Public Health Twin Panel (NIPHT), who all responded to a questionnaire. A subset of 2,793 individuals later underwent structured interviews. The best fitting model showed a strong genetic correlation of 0.82 (95% confidence interval; 0.61-1.0) between current self-report symptoms of anxiety and depression, and lifetime internalizing disorders, which suggests an almost complete overlap in genetic liability. The correlation between environmental factors was much lower: 0.16 (0.00-0.34, 95% CI). This implies that brief self-report scales capture genetic variance that is highly overlapping with the genetic variance common to internalizing disorder diagnoses. It thus follows that SCL-5 and similar instruments may be used as screening instruments for genetic risk factors that influence liability to internalizing disorders. In addition, existing data on self-report symptoms of anxiety and depression can be used with increased confidence to specify models including effects from genes coding for internalizing disorders.

Gene-environment interactions: early life stress and risk for depressive and anxiety disorders

RATIONALE

Prior reviews have examined how stress, broadly defined, interacts with genetic diathesis in the pathogenesis of internalizing (i.e., depressive and anxiety) disorders. Recent findings have suggested a unique role for early life stress (ELS) in the development of internalizing disorders, contributing to the rapid proliferation of research in this area.

OBJECTIVE

This paper critically reviews studies in humans examining gene-environment interaction (GxE) effects of ELS on the risk for depression and anxiety, primarily from a candidate gene perspective. Major methodological challenges that are unique to such studies are considered.

RESULTS

The majority of published studies have focused on candidates that regulate the serotonin system, especially the serotonin transporter. More recent work has addressed interactions of ELS with candidates from the hypothalamic-pituitary-adrenal axis and neurotrophin system. Available studies vary greatly with respect to definitions of ELS, examination of gene-gene interactions, consideration of gender effects, and attention to analytic limitations.

CONCLUSIONS

Overall, there is support for GxE effects of ELS on the risk for depressive and anxiety outcomes. Future studies of ELS in this context will require careful attention to methodologic considerations. Such studies would benefit from more systematic assessment of positive environmental factors (e.g., social support) and greater utilization of developmentally sensitive paradigms.

A population based family study of symptoms of anxiety and depression: the HUNT study

OBJECTIVE

To estimate an upper limit on the heritability of self-reported symptoms of anxiety and depression in a large and population representative nuclear family sample.

METHOD

The ten-item symptom checklist (SCL-10) was administered as part of a health survey in a Norwegian county. The SCL-10 is a shortened version of the SCL-25, assessing symptoms of anxiety and depression. In all, 46,064 people responded, and with data from Statistics Norway, responses of first-degree relatives could be linked. Polychoric correlations between family members score on SCL-10 were calculated, and a structural equation model was fitted to these correlations using the software package R.

RESULTS

All correlations between nuclear family members were in the range of 0.12 to 0.16, indicating small but significant familial influences on SCL-10. In the best fitting model, heritability was estimated at 0.25 (95% CI=0.22-0.27), and sibling specific environmental effects could be discarded.

CONCLUSIONS

The estimated upper level heritability for SCL-10 in our sample was lower than what has been reported in twin studies of similar measures.

Mental disorder and caregiver burden in spouses: the Nord-Trøndelag health study

Background

Researchers generally agree that mental disorder represents a burden to the family. The present study concerns the subjective burden of living with a person with mental disorder, more specifically the association between mental disorder in the index person and subjective well-being and symptoms of anxiety and depression in the spouse.

Methods

Data were obtained from questionnaires administered to the adult population of Nord-Trøndelag County, Norway during the period 1995-1997. The present study is based on a subsample where 9,740 couples were identified. Subjective burden in spouses of persons with mental disorder was compared with subjective burden in spouses of persons without mental disorder, using analysis of variance (ANOVA). All analyses were stratified by sex.

Results

Adjusting for several covariates, spouses of persons with mental disorder scored significantly lower on subjective well-being and significantly higher on symptoms of anxiety and depression compared to spouses of index persons without mental disorder. Although highly significant, the effect sizes were moderate, corresponding to a difference in standard deviations ranging from .34 - .51.

Conclusions

Our study supports the notion that there is an association between mental disorder in one partner and subjective burden in the spouse, but not to the same extent that have been reported in earlier studies, as our results do not indicate that a large proportion of the spouses reach a symptom level of anxiety and depression that reflects clinical mental disorder.

Effect of anxiety and depression on blood pressure: 11-year longitudinal population study

BACKGROUND

The long-term effect of anxiety and depression on blood pressure is unclear.

AIMS

To examine the prospective association of anxiety and depression with change in blood pressure in a general population.

METHOD

Data on 36 530 men and women aged 20-78 years participating in the Nord-Trøndelag Health Study (HUNT) in Norway in 1984-86 were re-examined 11 years later.

RESULTS

A high symptom level of anxiety and depression at baseline predicted low systolic blood pressure (< 10th percentile) at follow-up (OR=1.30, 95% CI 1.08-1.57) when those with low systolic blood pressure at baseline were excluded. Change in symptom level of anxiety and depression between baseline and follow-up was inversely associated with change in systolic blood pressure. For diastolic blood pressure, the findings were weaker or non-significant.

CONCLUSIONS

Symptoms of anxiety and depression predicted lower blood pressure 11 years later.

Parental control in the etiology of anxiety

Anxiety disorders are among the most prevalent forms of adult and childhood psychiatric disorders, and they are highly familial. However, the mechanisms of transmission remain unclear. One familial characteristic that may promote the development of anxiety is the construct of parental control. This paper provides a conceptual overview of the construct of control in the parenting and anxiety literatures, reviews existing literature on control in anxious families, and reviews current conceptual models of and developmental approaches to anxiety. Based on the current empirical literature, an elaborated model that takes child developmental level into consideration is proposed in order to provide a better understanding of the role of parental control in the development of anxiety.

Family functioning, perceived control, and anxiety: a mediational model

Research has focused on defining which types of family interactions promote development of anxiety. Control has emerged as an important construct in anxious families. Central to conceptualizing the relationship between family functioning, control beliefs, and anxiety is establishing a sequential relationship among these variable, which may entail mediating or moderating relationships, or relationships that change over the course of development. The current study investigated whether control acts as a moderator or a mediator between perceived family environment and anxiety in your adults. An undergraduate sample (N=364) completed the family assessment device (FAD), anxiety control questionnaire (ACQ), Beck anxiety inventory (BAI), and a demographic questionnaire. Structural equation modeling (SEM) was used to test both moderating and mediating models. No moderating effects were found. Sense of control mediated the relation between aspects of family functioning and anxiety. Theoretical implications and suggestions for future research are discussed.

A history of Norwegian psychiatry

In Norway the building of asylums started in 1855 with the establishment of Gaustad State Asylum. Until the 1950s Norwegian psychiatry was mainly a hospital psychiatry, strongly influenced by the pre-war German tradition. After World War II, it was influenced by British social psychiatry and American psychoanalysis. Psychiatric units in general hospitals were established in the 1960s onwards and outpatient clinics from the 1970s. During the last twenty years Norwegian psychiatry has taken a more biological trend with stronger emphasis on diagnostics and drug treatment. The increase in the number of psychiatrists and especially psychologists has been formidable during the last fifty years.

Active or passive journeys and low back pain in adolescents

The objective of this cross-sectional study was to study associations between low back pain (LBP) and modes of transport to school and leisure activities among adolescents. The study population included all adolescents in eighth and ninth grade in two geographic areas in eastern Norway. Eighty-eight adolescents participated (mean age 14.7 years), making the response rate 84%. Data concerning active (walking/bicycling) and passive (bus/car) journeys were obtained from lists and maps from local authorities, and from the pupils, using a questionnaire that also included LBP, activities and wellbeing. Distance walked/bicycled to school was slightly shorter among those reporting LBP in bivariate analyses. Walking/bicycling more than 8 km weekly to regular activities was inversely associated with LBP in multivariate analysis (OR 0.3; 95% confidence interval 0.1-1.0). No associations were found between passive journeys and LBP. The results raise the question for future research of whether lack of active transport may be one cause behind the increase in juvenile LBP.

The behavior of anxious parents: examining mechanisms of transmission of anxiety from parent to child

Examined the behavior of anxious parents in interactions with their children (ages 6 to 12 years) to test hypotheses about possible psychosocial mechanisms of transmission of anxiety from parent to child. Fifty-one parent-child dyads completed the study. Parents and children were assessed with structured interviews and participated in 2 tasks that were videotaped and coded. Twenty-five dyads had an anxious parent. Primary diagnoses of the anxious group were mostly panic disorder (PD), with or without agoraphobia (AG), social phobia (SP), and generalized anxiety disorder. Anxious participants were excluded if they presented a secondary diagnosis other than another anxiety disorder. Control parents had no present or past diagnosis. Observational data revealed that anxious parents were significantly less productively engaged and more withdrawn and disengaged during the interactions but did not differ from nonanxious parents in terms of overall levels of control. Sequential analyses indicated that there was a trend for both parent group and child sex to effect efforts to control the interaction in response to child expression of negative affect. Implications of these results for a mediational role of parental behavior in the development and maintenance of child anxiety are discussed.

The association between psychopathology in fathers versus mothers and children's internalizing and externalizing behavior problems: a meta-analysis

In light of the selective focus on maternal (vs. paternal) psychopathology as a risk factor for child development, this meta-analysis examines the relative strength of the association between psychopathology in mothers versus fathers and the presence of internalizing and externalizing disorders in children. Associations were stronger between maternal than paternal psychopathology and the presence of internalizing (but not externalizing) problems in children, with all average effect sizes being small in magnitude. Relations were moderated by variables that highlight theoretically relevant differences between psychopathology in mothers versus fathers (e.g., age of children studied, type of parental psychopathology) and by variables related to methodological differences across studies (e.g., method of assessing psychopathology in parents and children, type of sample recruited, familial composition).

The significance of high lumbar mobility and low lumbar strength for current and future low back pain in adolescents

STUDY DESIGN

This study comprised a cross-sectional part and a prospective part.

OBJECTIVE

To study whether low lumbar extension strength, high lumbar mobility, and high mobility-extension strength ratios are related to current and future low back pain in adolescents.

SUMMARY OF BACKGROUND DATA

Knowledge is sparse about the significance of lumbar mobility and strength for low back pain in adolescents.

METHODS

The study population included all the adolescents in the eighth and ninth grades of a rural municipality (n = 44) and in an urban area (n = 61) during the 1996-1997 school year. At baseline, 88 adolescents (mean age, 14.7 years) participated in the study, giving a response rate of 84%. Low back pain was assessed by questionnaire as pain or discomfort in the low back during the preceding year. Sagittal lumbar mobility was tested by Schober's modified technique, and lumbar strength as static endurance extension strength. The follow-up part was conducted 3 years later, which included 98% of the adolescents.

RESULTS

By bivariate and multivariate analyses in the cross-sectional part of the study, low back pain was found to be highly associated with low lumbar extension strength (P = 0.004-0.02), and high lumbar mobility-extension strength ratios (P = 0.005-0.04). Baseline low lumbar extension strength and high lumbar sagittal mobility-extension strength ratios (P = 0.03 and P = 0.02, respectively) predicted low back pain at follow-up assessment in multivariate analyses when control was used for gender, previous low back pain, physical activity, and well-being. No associations were found between plain sagittal mobility and low back pain.

CONCLUSION

The study findings support theories suggesting insufficient strength and stability in the low back as important factors for both concurrent and future low back pain in adolescents.

Nature, nurture and mental disorder: old concepts in the new millennium

BACKGROUND

Evidence from twin and adoption studies has highlighted the importance of gene-environment interaction in the aetiology of mental disorders, and advances in molecular genetics have raised hopes of more rapid progress in this field of investigation.

AIMS

To review epidemiological knowledge concerning genetic and environmental risk factors for a cross-section of psychiatric conditions, and evidence of interaction between the two types.

METHOD

Searches of the literature in genetic and psychiatric epidemiology, including contributions to this supplement.

RESULTS

Overall, firm knowledge on both genetic and environmental causal factors is still fragmentary, although progress has varied among diagnostic categories. Environmental aspects have been dealt with only perfunctorily in most genetic epidemiological research.

CONCLUSIONS

Better definition and classification of environmental hazards, and closer inter-disciplinary cooperation, will be necessary in future. Specific gene-environment interaction effects seem likely to prove most important in neuropsychiatric syndromes, and a less specific genetic influence on susceptibility to environmental stress among the common mental disorders.

Mental distress and risk of hip fracture. Do broken hearts lead to broken bones?

OBJECTIVE

Mental distress may entail increased risk of hip fracture, but it is uncertain whether the effect consists solely of an indirect effect through use of medication, or whether it is also mediated through other mechanism. The purpose of this study was to examine the association between mental distress and risk of hip fracture in women, adjusted for medication (that is, use of tranquillisers/sedatives or hypnotics).

DESIGN

A three year follow up of hip fracture was conducted on 18,612 women, consisting of 92.5% of all women aged 50 years or older in a Norwegian county. Three hundred and twenty nine suffered a hip fracture. A mental distress index was based on questions about life dissatisfaction, nervousness, loneliness, sleep disorders, troubled and uneasy feelings, depression and impairment attributable to psychological complaints. Relative risk with 95% confidence intervals (CI) of hip fracture with respect to mental distress were controlled for medication, age, body mass index (BMI), smoking, physical inactivity, and physical illness by means of Cox regression.

RESULTS

The 10% of women with the highest mental distress had more than twofold increased risk of hip fracture compared with the 10% of women with the lowest mental distress, after adjustment for age and medication. The relative risk was 1.95 (95% CI 1.2, 3.3) after additional control for BMI, smoking, physical inactivity, and physical illness. The relative risk of hip fracture for daily users of medication compared with never users was 2.1 (95% CI 1.6, 2.9). After adjusting for mental distress it was 1.5 (95% CI 1.0, 2.2).

CONCLUSIONS

Risk of hip fracture was positively related to mental distress, also after adjustment for medication use. The effect of tranquillisers/sedatives or hypnotics on hip fracture risk may be overestimated in studies with no adjustments for mental distress.

Use of minor tranquilizers among Norwegian physicians. A nation-wide comparative study

The use of minor tranquilizers (hypnotics and anxiolytics) during the last month before a questionnaire was answered was studied in a postal survey of a nation-wide representative sample of Norwegian physicians (n = 1467), aged 25 to 69 years. The response rate was 73%. A total of 12.2% of the physicians had used minor tranquilizers in the past month, one third of these on a daily or weekly basis. There was no gender difference. High age, high mental distress, and working outside the hospital was identified as risk factors for drug use. Compared to a representative sample of subjects from the general population with the same age and education level, (The Nord-Trøndelag Health Survey), more male physicians than males in the comparison sample had used minor tranquilizers in the past month, also when controlled for subjective well-being. However, the physicians had used the drugs more sporadic. When self-prescription of minor tranquilizers was studied in a different sample of 1024 Norwegian physicians, it was found that 72.6% of the physicians had self-prescribed the drugs. There was no gender difference in self-prescribing.

Genetics and developmental psychopathology: 2. The main effects of genes and environment on behavioral problems in the Virginia Twin Study of Adolescent Behavioral Development

Little is known about the contribution of genetic and environmental factors to risk for juvenile psychopathology. The Virginia Twin Study of Adolescent Behavioral Development allows these contributions to be estimated. A population-based, unselected sample of 1412 Caucasian twin pairs aged 8-16 years was ascertained through Virginia schools. Assessment of the children involved semi-structured face-to-face interviews with both twins and both parents using the Child and Adolescent Psychiatric Assessment (CAPA). Self-report questionnaires were also completed by parents, children, and teachers. Measures assessed DSM-III-R symptoms of Attention Deficit Hyperactivity Disorder (ADHD). Conduct Disorder, Oppositional Defiant Disorder, Overanxious Disorder, Separation Anxiety, and Depressive Disorder. Factorially derived questionnaire scales were also extracted. Scores were normalized and standardized by age and sex. Maximum likelihood methods were used to estimate contributions of additive and nonadditive genetic effects, the shared and unique environment, and sibling imitation or contrast effects. Estimates were tested for heterogeneity over sexes. Generally, monozygotic (MZ) twins correlated more highly than dizygotic (DZ) twins, parental ratings more than child ratings, and questionnaire scales more highly than interviews. DZ correlations were very low for measures of ADHD and DZ variances were greater than MZ variances for these variables. Correlations sometimes differed between sexes but those for boy-girl pairs were usually similar to those for like-sex pairs. Most of the measures showed small to moderate additive genetic effects and moderate to large effects of the unique individual environment. Measures of ADHD and related constructs showed marked sibling contrast effects. Some measures of oppositional behavior and conduct disorder showed shared environmental effects. There were marked sex differences in the genetic contribution to separation anxiety, otherwise similar genetic effects appear to be expressed in boys and girls. Effects of rater biases on the genetic analysis are considered. The study supports a widespread influence of genetic factors on risk to adolescent psychopathology and suggests that the contribution of different types of social influence may vary consistently across domains of measurement.

Diabetes mellitus and psychological well-being. Results of the Nord-Trøndelag health survey

The present study relies on questionnaire data from a diabetes and hypertension screening carried out on the entire adult population of a medium-sized Norwegian county (total number of participants = 74,977). Self-reported diabetic patients were compared with non-diabetics, and with patients with self-reported angina pectoris, previous cardiac infarction, and stroke. The psychological well-being of the known diabetic patients was found to be significantly poorer than that of those without diabetes, but better than that of those with angina and stroke. HbAl level was found to be significantly related to well-being, the low levels of HbAl (below 7.5%) scoring low on well-being and the high levels (above 15%) scoring high. Because of its special design, the present study allowed comparisons between diabetic patients undergoing treatment and newly detected patients who had not yet been treated. Treatment-related interpretations therefore could be rejected.

Genetic factors in early separation anxiety: implications for the genesis of adult anxiety disorders

An important contemporary conceptualization of anxiety has suggested that heightened early separation anxiety is specifically associated with the risk of adult panic disorder, with hereditary factors underlying that cluster of anxiety disorders. Yet there is a dearth of studies examining whether early separation anxiety is inherited. The present twin study, based on a retrospective approach, revealed a substantial genetic contribution to separation anxiety in females but not in males, with unique environmental influences being important in both gender groups. Although speculative, an evolutionary explanation is offered to account for the apparent gender difference in the inheritance of early separation anxiety. It is hypothesized that, in some women, phylogenetic vestiges of separation anxiety may conflict with their need to compete in an individualistic manner in the modern workplace. Whether such an attachment-autonomy conflict accounts for the increased rate of panic disorder and agoraphobia in women is worthy of further study.

Sex-specific causal factors and effects of common environment for symptoms of anxiety and depression in twins

Two thousand five hundred seventy intact pairs and 724 single responders from Norwegian twins aged 18-25 years completed questionnaires with information about anxiety and depression and perceived cotwin closeness. The aim of the study was the univariate estimation of sex-specific genetic and environmental effects on an index tapping symptoms of anxiety and depression. An index of social closeness between cotwins was significantly related to the cotwin correlation for anxiety/depression scores. MZ pairs were reported to be closer than DZ pairs, and like-sexed DZ pairs were closer than unlike-sexed pairs. The symptom data were adjusted for this apparent violation of the "equal-environment" assumption in twin studies, but the adjustment did not dramatically affect the parameter estimates of genetic and environmental effects on anxiety/depression. A model specifying male (aM) and female (aF) genetic additive effects, shared environment for males (cM), and individual environmental effects (eM and eF) fitted the adjusted data very well. An alternative model, specifying aM = aF, cM = cF, and eM = eF, and no correlation between those environmental factors shared by brothers and those shared by sisters, fitted equally well. Estimated proportions of total variance from the first model were aM2 = .30, aF2 = .52, and cM2 = .21. The estimates from the second model were aM2 = aF2 = .43 and cM2 = cF2 = .11.