Our findings suggest that at younger ages, death from coronary heart disease is influenced by genetic factors in both women and men. The results also imply that the genetic effect decreases at older ages.

The Swedish Twin Registry (STR), which today has developed into a unique resource, was first established in the late 1950s to study the importance of smoking and alcohol consumption on cancer and cardiovascular diseases whilst controlling for genetic propensity to disease. Since that time, the Registry has been expanded and updated on several occasions, and the focus has similarly broadened to most common complex diseases. 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. Compiling the RegistryThere are three cohorts in the registry, each of which differs in method of ascertainment and extent of data collected. The compilation of the first two cohorts has been described previously [1,2] and in the following, we describe the current structure of the registry.The cohort born in When the twin registry was initiated, all parishes in Sweden were contacted to obtain information concerning multiple births between 1886 and 1925. Each potential pair of twins was manually followed until status in 1959 was established. In 1960-61, a questionnaire was sent to all like-sexed twins where both were alive and living in Sweden. Since then questionnaires have been sent out in 1963 and 1967 (Table 1). Only the information from pairs in which both responded was kept from the initial questionnaire and the 1963 questionnaire. Depending on nonresponse to the 1967 questionnaire or some items in that questionnaire, selected pairs were requested to respond to a questionnaire in 1970. The information was mainly of demographic, medical and life-style character, with special attention to cardiovascular and respiratory disease, general health, legal drug use, diet and psychosocial conditions (Fig. 1). Recently information from 1699 unlike-sexed pairs born in 1906-25 has been Journal of Internal Medicine 2002; 252: 184-205 184 Ó 2002 Blackwell Science Ltd computerized and matched on name, date and county of birth [3]. The registry is regularly matched to national health care registries to obtain information on cancer diagnoses, inpatient discharges, causes of death, and current address and vital status. The cohort born in 1926-58In 1970 a new cohort of twins born in 1926-67 was compiled, this time by use of nationalized birth registrations. A birth register consisting of all 50 000 twin births was established [2]. Members of like-sexed pairs from the cohort born in 1926-58 were sent a mail out questionnaire in 1972-73. Responses were received from about 36 000 individuals including 14 000 twin pairs. This questionnaire was very similar to those sent to the older cohort. In addition, a short version of the Eysenck Personality Inventory was developed [4] as well as a series of questions about environmental agents such as air pollution and noise. Information is maintained concerning both the initial birth cohort as well as Note: Not eligible means not alive at time of sending out questionnaire...

Across a range of countries in Europe, using the Young Diagnostic Questionnaire for Internet Addiction yields a prevalence of 'pathological internet use' of 4.4% among adolescents, but varies by country and gender; adolescents lacking emotional and psychological support are at highest risk.

Objective-To analyse incidence of sickness for women and men relative to potential aetiological factors at workphysical, psychosocial, and organisational. Methods-The study group comprised 1557 female and 1913 male employees of Sweden Post. Sickness absence was measured by incidence of sickness (sick leave events and person-days at risk). Information on explanatory factors was obtained by a postal questionnaire, and incidence of sickness was based on administrative files of the company. Results-Complaints about heavy lifting and monotonous movements were associated with increased risk of high incidence of sickness among both women and men. For heavy lifting, an odds ratio (OR) of 1.70 (95% confidence interval (95% CI) 1.22 to 2.39) among women, and OR 1.70 (1.20 to 2.41) among men was found. For monotonous movements the risk estimates were OR 1.42 (1.03 to 1.97) and OR 1.45 (1.08 to 1.95) for women and men, respectively. Working instead of taking sick leave when ill, was more prevalent in the group with a high incidence of sickness (OR 1.74 (1.30 to 2.33) for women, OR 1.60 (1.22 to 2.10) for men). Overtime work of more than 50 hours a year was linked with low incidence of sickness for women and men. Among women, 16% reported bullying at the workplace, which was linked with a doubled risk of high incidence of sickness (OR 1.91 (1.31 to 2.77)). For men, the strongest association was found for those reporting anxiety about reorganisation of the workplace (OR 1.93 (1.34 to 2.77)). Conclusions-Certain physical, psychosocial, and organisational factors were important determinants of incidence of sickness, independently of each other. Some of the associations were sex specific. (Occup Environ Med 2001;58:178-184)

Rising global rates of pathological Internet use (PIU) and related psychological impairments have gained considerable attention in recent years. In an effort to acquire evidence-based knowledge of this relationship, the main objective of this study was to investigate the association between PIU, psychopathology and self-destructive behaviours among school-based adolescents in eleven European countries. This cross-sectional study was implemented within the framework of the European Union project: Saving and Empowering Young Lives in Europe. A representative sample of 11,356 school-based adolescents (M/F: 4,856/6,500; mean age: 14.9) was included in the analyses. PIU was assessed using the Young's Diagnostic Questionnaire. Psychopathology was measured using the Beck Depression Inventory-II, Zung Self-Rating Anxiety Scale and Strengths and Difficulties Questionnaire. Self-destructive behaviours were evaluated by the Deliberate Self-Harm Inventory and Paykel Suicide Scale. Results showed that suicidal behaviours (suicidal ideation and suicide attempts), depression, anxiety, conduct problems and hyperactivity/inattention were significant and independent predictors of PIU. The correlation between PIU, conduct problems and hyperactivity/inattention was stronger among females, while the link between PIU and symptoms of depression, anxiety and peer relationship Michael Kaess and Tony Durkee contributed equally to this paper and therefore both should be considered as first authors. 123Eur Child Adolesc Psychiatry (2014) 23:1093-1102 DOI 10.1007 problems was stronger among males. The association between PIU, psychopathology and self-destructive behaviours was stronger in countries with a higher prevalence of PIU and suicide rates. These findings ascertain that psychopathology and suicidal behaviours are strongly related to PIU. This association is significantly influenced by gender and country suggesting socio-cultural influences. At the clinical and public health levels, targeting PIU among adolescents in the early stages could potentially lead to improvements of psychological well-being and a reduction of suicidal behaviours.

Occupational exposure to low-frequency electromagnetic fields (EMF) was studied in 250 leukemia patients and 261 brain-tumor cases, diagnosed in 1983-87 and compared with a control group of 1,121 randomly selected men, from the mid-region of Sweden, 1983-87. We based the exposure assessment on measurements from 1,015 different workplaces. On the basis of the job held longest during the 10-year period before diagnosis, we found an association between the average, daily, mean level of EMF and chronic lymphocytic leukemia (CLL). The risk increased with increasing level of exposure. The odds ratios (OR) and the 95 percent confidence interval (CI) for three consecutive levels of exposure were: 1.1 (CI = 0.5-2.3); 2.2 (CI = 1.1-4.3); 3.0 (CI = 1.6-5.8), respectively. No association was observed for acute myeloid leukemia (OR = 1.0, CI = 0.5-1.8; OR = 0.8, CI = 0.4-1.6; OR = 1.0, CI = 0.6-1.9). For brain tumors, the corresponding risk estimates were 1.0 (CI = 0.7-1.6); 1.5 (CI = 1.0-2.2); 1.4 (CI = 0.9-2.1). Different EMF indices were tested. Tasks with frequent or large variations between high and low field-densities (high standard deviation) were more common among CLL subjects. For brain tumors, a prolonged high level (high median values) showed the strongest association. Confounding by place of residence, smoking, benzene, ionizing radiation, pesticides, and solvents was evaluated, and these factors did not seem to have a decisive influence on the associations. We also analyzed other potential sources of bias. For CLL, there were indications of an excess number of low-exposure subjects among non-responders, which, to some extent, may have enhanced but not caused the risk estimates obtained. Our conclusion is that the study supports the hypothesis that occupational EMF exposure is a hazard in the development of certain cancers.

Parental morbidity and parental suicidal behaviour show the most detrimental effects on completed suicide among offspring when they appear early in life. Early interventions in families at risk are necessary to prevent suicide in offspring.

Negative effects of long-term sick leave were particularly related to leisure activities, sleep and psychological well-being. A reduced alcohol intake was more prevalent than increased consumption. Among individuals with psychiatric diagnoses the consequences were polarized, with few persons unaffected, while the effects were more unipolar and negative in other diagnostic groups. Women experienced positive consequences more often than men, attributed to relationships with children and partner, sleep and psychological well-being. Improved sleep was associated with return to work, particularly among older individuals. Negative consequences on life situation are far more common than positive consequences among patients on long-term sick leave. Benefits as well as adverse effects differ depending on diagnosis, age and gender.