Quality of sleep during economic recession in Finland: a longitudinal cohort study.

To assess the association between the economic recession of the 1990s in Finland and sleep behaviour, a longitudinal study was conducted in an adult Finnish population cohort. Baseline data were obtained by means of reports on sleep behaviour, health-related behaviour, health status, and objective laboratory tests in 1983-1987. The second screening conducted in 1992-1995, i.e. during economic recession, repeated data collection by postal questionnaires. The prevalences of various sleep symptoms including insomnia, daytime tiredness, fatigue, parasomnias and the use of hypnotics remained similar in the same age cohorts during economic recession. Alcohol consumption and snoring increased among the middle-aged (30-49 years), though snoring shows the greatest individual stability among various sleep symptoms. Despite some baseline differences in the sleep/health behaviour frequencies, the changes were independent of gender and socioeconomic class. The prevalences over eight years of insomnia and snoring show fair chronicity, whereas daytime tiredness and fatigue seem to be less chronic. Middle-aged participants who were stably employed at the initial screening but became unemployed during economic recession were studied separately. Prospectively unemployed persons suffered more from insomnia and used more hypnotics than the continuously employed. We conclude that the sleep quality of the general Finnish population has not drastically deteriorated during severe economic recession except among unemployed blue-collar workers.