Refugees are exposed to several risk factors for mental ill health before, during, and after the migration. While the impact of traumatic experiences on the mental health of refugees is well-known, the effect of adverse experiences and circumstances in the post-migration context have been less investigated, although a shift has been seen in recent years.

The overall aim of this thesis was to increase the knowledge on post-migration stress and its associations with mental ill health among refugees. The thesis is based around a crosssectional and population-based survey among refugees from Syria who were granted permanent residence permit in Sweden between 2011-2013.

The objective of Study I was to estimate the prevalence of mental ill health and its associations to potential traumas and post-migration stress among refugees from Syria recently resettled in Sweden. A postal questionnaire was sent to a random sample of 4 000 individuals aged 18-64 years drawn from a sample frame containing all eligible participants. Access to registered-based information enabled the construction of non-response weights. Weighted analyses were conducted to calculate prevalence rates and associations, and associations were investigated through a series of logistic regression analyses. Results indicate that prevalence rates for anxiety, depression, PTSD, and low SWB are highly elevated among refugees from Syria with a majority meeting criteria for at least one of the included measures of mental ill health. Furthermore, experiences of potentially traumatic events (PTEs) before and during the migration as well as experiences of post-migration stress were common. Most types of PTEs and post-migration stress were associated with increased risk for mental ill health.

The objective of Study II was to develop and validate the Refugee Post-Migration Stress Scale (RPMS), an instrument for assessing refugee-related post-migration stress. The development was conducted in two phases. In the first phase, a preliminary instrument was developed based on a theoretical model of post-migration stress, covering seven hypothesized domains: perceived discrimination, lack of host country specific competences, material and economic strain, loss of home country, family and home country concerns, social strain, and family conflicts. In the second phase, the factorial structure of the instrument was investigated in the context of the survey described in Study I, using Confirmatory and Exploratory Factor Analyses. The analyses resulted in a 7-factor model of post-migration stress that showed excellent fit to data. The final version of the RPMS contains 21 items for assessing refugeerelated post-migration stress across seven domains.

Experiences of post-migration stress are common among refugees from Syria recently resettled in Sweden, and as the results in this thesis show, post-migration stress is associated with increased risk for mental ill health. In order to facilitate recovery from traumatic experiences, measures should be taken on a societal level to mitigate the adverse effects of post-migration stress among refugees.