General Characteristics of Participants across chronotype
The characteristics of the 1022 (96.2%) subjects included in present study are shown in Table 1 . Overall, participants included a total of 608 females (59.5%) and 514 males (40.5%), with 44.7% (n = 457) of individuals aged 30 to 34 years. According to the MEQ scores, approximately 9.39% of the participants were identified as evening chronotype, while 68.2% were neutral chronotype and 29.06% were morning chronotype. Significant differences were found for age, passive smoking, education, annual income, frequency of insomnia, daytime napping, and living children compared to these three groups (all p <0.05). Specifically, participants in the evening chronotype were more likely to be younger, to be free of passive smoking, had a high or vocational school education level, a higher annual income, more frequent insomnia, never daytime napping, lower level of physical activity as well longer sleep and social jetlag times and shorter infertility treatment times. In addition, we observed that 527 individuals reported mild and above depressive symptoms, representing 51.6% of the total subjects, with a trend toward a decrease in depressive symptoms as the chronotype from evening to neutral and then to morning. The characteristics of participants according to depressive phenotype are shown in Table S1 .