Association between sleep time and depression: a cross-sectional study from countries in rural Northeastern China.

Objective To investigate the current situation of sleep status and examine its association with depression among counties in rural areas of Liaoning Province, China. Methods This cross-sectional study was conducted from January 2012 to August 2013 in Northeast China. A total of 11,276 subjects aged ≥35 years were surveyed and completed the Patient Health Questionnaire-9; each participant answered questions about their sleep duration. Results For individuals with a sleep time of ≤6, 6-7, 7-8, 8-9, and ≥9 h, the respective risk of depression was 10.8%, 3.7%, 2.6%, 2.7%, and 5.7% in subjects younger than 65 years old and 15.2%, 5.4%, 3.2%, 6.5%, and 8.6% in those 65 years old or older. Conclusion In the rural population of Liaoning Province, sleep duration and depression are closely related. Both short sleep and long sleep are risk factors for depression. Optimizing sleep status may contribute to good physical and mental health.