OBJECTIVE/BACKGROUND: 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.

PATIENTS/METHODS: 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%), M age = 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.

RESULTS: The minimum prevalence rate was 23.48% (M age = 32.11, SD = 0.40), and the maximum was 47.83% (M age = 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.

CONCLUSIONS: 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.