Addi van Bergen

Systematic review: social exclusion or inclusion and health 37 2 such as social isolation, housing or access to health care, are beyond the scope of this review as our focus was solely on papers employing a multidimensional interpretation of the concept SE/SI. Second, more comprehensive concepts such as social cohesion, social capital, citizenship or (multiple) poverty, were deliberately kept out of the study too, because of the general consensus in the literature that these concepts, although appearing similar to SE/SI, differ in important ways [2, 10-12, 20, 26]. Studies on socio-economic position or ethnicity and health are also out of the scope of this review as occupation, education and ethnic background are regarded as risk factors for SE and not as constituent parts [21]. Nevertheless, bias to the use of key words cannot be ruled out and a more extensive search strategy could be considered in future reviews. Implications for future research Our paper revealed a great number of weaknesses in research methodology and provides ideas and directions for future research. A research agenda required to have a better understanding of potential mechanisms and putative pathways should include longitudinal studies, studies into mediating and modifying factors such as gender and previous disadvantage; and into the accumulation and interaction of SE/SI dimensions. Equally important for enhancing the knowledge base on SE/SI and health, is a more systematic and standardised terminology of SE/SI domains and the development and validation of composite measures of SE/SI. The WHO/SCP model used in this paper may serve here as a useful template [3, 25, 26]. Policy implications The association between high SE and poor MH came most clearly to the fore in people with severe mental illness and substance use disorder. Through the implementation of recovery-orientated services, the mental health sector can contribute to the SI of their clients [58], but more may be needed. As several studies in our review show an association between the economic and political dimensions of SE/SI and MH, e.g. with income, economic deprivation, employment, education and housing, we expect that there may be little chance of improving the situation of those with mental health problems without attention being given to these other problems. These need to be addressed by social and economic policies [58], involving not just the health sector but a range of sectors and services such as housing, employment, education, income support, debt counselling, and community building [59-62]. The evidence on the association between SE/SI and poor mental and general health in the general population also calls for more macro level policies and interventions, targeting the general population and not only those at highest risk.