Background: People's mental health was negatively affected by the restrictions on public life during the COVID-19 pandemic. Systematic research on the short- and long-term consequences of the COVID-19 pandemic on suicidal behavior is fundamental for developing suicide-preventive measures adapted to the current situation. Methods: Between January 1, 2017, and December 31, 2021, we included patient records that met the DMS-5 criteria for suicidal behavior disorders (n = 825) admitted to a psychiatric hospital in a rural region in Germany. To examine the impact of the pandemic on SA occurrence, time trends, and seasonal variations, we used interrupted time-series Poisson regression models. Results: There was no significant effect of the pandemic on the occurrence of SA in the overall group. However, we observed a significant impact of the pandemic on the seasonal pattern of SA, also the variance differed significantly (pre-pandemic mean ± variance: 13·33 ± 15·75, pandemic: mean ± variance: 13·86 ± 7·26), indicating less periodic variation in SA during the pandemic. Male patients and young adults mainly contributed to this overall effect. Subgroup analysis revealed a significant difference in SA trends after pandemic in older adults (>55 years) compared with younger adults (18-35 years); SA numbers increased in older adults and decreased in younger adults as the pandemic progressed. Limitations: Adolescent patients and patients with a COVID-19 infection were not included into the current study. It remains unclear to which extend emergency departments and outpatient care had contact with the patients after SA, potentially not referring them to psychiatric hospitals in the crisis situation. Conclusions: Public life restrictions in the rural region during the COVID-19 pandemic appear to have had a differential impact on suicidality in individual age groups. The changes in seasonal patterns could be the result of changing stresses and perspectives during the crisis and could differ from urban populations.