This doctoral thesis examines various factors associated with subjective well-being (SWB) in an adult Swedish population, aged 20-64 years, using cross-sectional and longitudinal data. The thesis includes four studies based on the PART study, a current population-based study on mental health, work, and relations in Stockholm County, Sweden. Research has shown that there is a relationship between mental health problems such as depression and low well-being. It is therefore of great interest to investigate various factors associated with SWB in order to promote or increase mental health. We also examined if the well-being scale used in all studies could be used as a screening instrument for depression.

The specific aim of Study I was to examine if age, gender, foreign background (i.e. not born in Sweden), cohabitation, education, financial strain, social support, childhood conditions and negative life events and their associations with SWB could be replicated in our data. In Study II we investigated strategies people chose to employ in order to improve or maintain their well-being and whether these were associated with SWB. Study III examined if changes in cohabiting, social support or the financial situation influenced SWB, after controlling for neuroticism at a 3-year follow-up. The change in the study sample’s SWB was also studied during the same time period. In Study IV the aim was to investigate whether the well-being scale, the (WHO) Ten Well-being index, could be used as a screening instrument for depression.

Results from Study I showed that men had higher SWB than women, and that positive childhood conditions, cohabiting, greater age, sound financial situation, absence of negative life events, and support from friends were all positively associated with SWB. Social support had the strongest relationship. Together, these factors explained 20 % of the variance in SWB and the findings replicated earlier research. The strategies reported in Study II were physical exercise, physical health,engaging in pleasurable activities, relaxation, plan/set limits, social support, professional contacts, positive thinking, and work. Of these, social support, relaxation, physical exercise and physical health were associated with higher SWB. Social support showed the strongest association. In Study III changes in financial situation, social support, or cohabiting influenced SWB after controlling for neuroticism. The results also suggested that SWB was relatively stable over a period of three years. Preliminary findings from Study IV indicate that the (WHO) Ten Well-being index can work as a screening instrument for depression in populationbased samples.

In summary, the findings suggest that demographics and psychosocial factors explain only a small part of the variance in SWB, replicating previous data. Certain self-care strategies are positively associated with SWB. In addition, changes in life circumstances influence SWB, even after controlling for neuroticism over a period of three years despite the stability of SWB. Furthermore, the preliminary findings indicate that the well-being scale can work as a screening instrument for depression in a population-based sample. The overall conclusion from the results of this thesis suggests that it is important for the health care services to be aware that negative life events/circumstances may affect people’s SWB over several years. Furthermore, selfhelp interventions might be important in order to maintain or increase SWB.