Insomnia symptoms in adulthood. Prevalence and incidence over 25 years

Despite its high prevalence, little information is available about the course of insomnia symptoms over the life span. In this study, we analyzed the self-reported insomnia symptoms of the general population over more than 20 years, covering young up to middle adulthood. Data from waves 12 to 32 of the Saxon Longitudinal Study (1996–2021), were analyzed. Based on data from the 12th wave, n = 115 adults (48 men (41.7%), 67 women (58.3%), Mage = 23.59, SD = 0.59) completed the G-Score Item #3 in the following 18 waves, thus forming the basis for our analyses. The G-Score Item #3 reads “In the last 12 months, have you had the following complaints? Please indicate how often they occurred – Insomnia”. The G-Score Item #3 was dichotomized using a cut-off score of 2, and prevalence and incidence rates were calculated by gender. The minimum prevalence rate was 23.48% (Mage = 32.11, SD = 0.40), and the maximum was 47.83% (Mage = 48.43, SD = 0.64), indicating an increase in insomnia symptoms with age. In most cases, no evidence was found for gender differences in prevalence rates. The incidence rates were 10.43% for the 1st year of follow-up and 8.7% for the 5th year and 6th year of follow-up, respectively. This study provides further evidence for the high prevalence rates of insomnia symptoms in the general population. As this study is the first epidemiological study of insomnia symptoms based on a single-item (screening) instrument, it should be rather seen as an extension than a replication of previous study findings.