BMC Public Health 2007, 7:27 http://www.biomedcentral.com/1471-2458/7/27 explain. The isolation from the West by half a century of war and communist rule, the Iron Curtain, and the forced inclusion in the Soviet Bloc with the compulsory creation of the "Soviet-style regimes" [2] have all had a profound influence on the economy, social fabric, and health of the population in these countries and, although diminishing, the consequences are still visible. The former Soviet Bloc countries are worse off economically and the health rates there are lower than in the Western Europe [3]. Conse- quently, migration from these countries may cause a change in service needs and/or health patterns in the host societies. To prevent or manage such a change success- fully, it is important to learn about the health of this immigrant group. The present study attempted to procure knowledge about the self-reported mental health of immi- grants from the former Soviet Bloc currently living in Swe- den. Self-reported mental health (defined here as self-reported psychiatric illness and psychosomatic complaints) was the focus of this study because mental health is funda- mentally interconnected with physical and social func- tioning and health outcomes and is therefore crucial to the overall well-being of individuals, societies, and coun- tries [4]. Moreover, in general, self-reported health is a reliable indicator of the health status of a population, pre- dicting, as it does, mortality, morbidity, and other clinical outcomes [5,6]. Migration to Sweden from the Soviet Bloc to Sweden after 1944 Sweden, at the crossroads between the two sides of the Iron Curtain, has become not only one of several transit countries, but also a place of residence for numerous immigrants from Eastern Europe and the former Soviet Union (FSU) after the dissolution of the Soviet Bloc in 1989 and the FSU in 1991, with increasing migration from east to west. Even before that, refugees sought asy- lum in Sweden after revolts and political persecutions in the Soviet Bloc. However, due to the Cold War and the Iron Curtain, which significantly reduced European East- West migration, for a long time migration from countries of the former Soviet Bloc to Sweden was characterized by distinct 'waves' of migration directly linked to political events in the countries of emigration [7]. Some of the major events are presented in Table 1. However, the immi- gration politics of Sweden has also influenced this migra- tion. For example, in the mid-70s, migration to Sweden was made easier for Polish-born individuals by the aboli- tion of the necessity to obtain visas [8]. Sweden also started to recruit workers from Hungary in 1947. By 2001 there were about 110,000 immigrants from the former Soviet Bloc in Sweden. Table 2 illustrates the arrival patterns of these immigrants, which correspond to occurrences of major political events in these countries. Many of the immigrants from Hungary and the former Czechoslovakia arrived before 1969, i.e. in response to, respectively, the revolution in 1956 and the so-called "Prague Spring" in 1968. The arrival of Poles in Sweden dates back mostly to the 1970s, with an increase after the military coup in 1981. It was virtually impossible for inhabitants of the FSU to migrate before the breakdown of the empire and abolition of migration restrictions which resulted in the arrival of a wave of immigrants from the various former republics in Sweden after 1991. Health determinants among immigrants from the countries of the former Soviet Bloc. A review of the literature Immigrants from the former Soviet Bloc have not been systematically studied as a group and previous studies have mostly focused on immigrants from the FSU. How- ever, the determinants of mental health reported by these studies generally correspond with the characteristics which are known to determine the health (in terms of mortality, morbidity, or self-reported health) of the pop- ulation in various countries of the former Soviet Bloc and which, we assume, can be associated with mental health among immigrants from these countries as well. Age [9], sex [10,11], and marital status [12,13] have often been associated with the mental health of immigrants from the FSU. Social capital is another widely-discussed health determi- nant. In Russia, and supposedly in other former Soviet Bloc countries [14], social capital takes the form of infor- mal social networks, such as the family, relatives and friends, rather than formal institutions [15]. Studies in the countries of the former Soviet Bloc and on immigrants from these countries show that the support received from friends [16,17], emotional support in general [18], and social support [18-21] have a profound effect on health. Thus those without social networks are especially vulner- able [15]. Brown and Harris [22] underlined the impor- tance of social networks for mental health, suggesting that coping with stressful events depends on whether a person has access to a social network as a protective factor. Socioeconomic status (SES) and many of its components, such as occupation (a socioeconomic classification charac- teristic used in Sweden [23]), are also known to be associ- ated with the mental health of immigrants from the FSU [24]. Housing tenure (owning or renting one's living quar- ters) is another important SES characteristic for studying a person's health. Residential areas with privately owned homes are occupied by people with good resources. The turnover of residents is less intensive in such areas and, consequently, there are more contacts between neighbors. Page 2 of 12 (page number not for citation purposes)