Life events or life processes as determinants of mental strain? A 5-year follow-up study.

In a study among Finnish metal industry employees (n = 748) mental strain was measured at the beginning and at the end of a 5-year follow-up. Life event data for the follow-up period were gathered retrospectively through a questionnaire and a later interview. Mental strain was substantially higher among blue-collar than white-collar workers. In contrast, no differences in the occurrence or in the rating of life events was observed between these groups. Self-rated undesirable events were associated with high levels and desirable events with low levels of mental strain. Similar associations were observed in three objectively defined live events, viz. divorce, promotion in the job and change in housing conditions. Life events were, however, also related with the mental strain measured prior to the life events. Both the self-rated and objectively defined desirable events had usually a favourable impact on mental well-being, whereas undesirable events in most cases slightly increased mental strain. The differences in mental strain between occupational status groups seem to be caused by differences in the life processes rather than life events. Furthermore, many life events, e.g. divorce, are actually only discrete moments in long-lasting processes, which have an impact on mental well-being. And last, desirable life events can be seen rather as a preventive than a risk factor of mental strain.