Table 1.

Variable implications and descriptive statistics.

Variable name	Variable meaning	Mean	Standard error	N
Dependent variable
Mental health	The total scores of 20 depressive symptoms	7.286	9.043	801
Core independent variable
AI	Unused = 0, used = 1	0.260	0.439	800
Mediating variable
Work overtime	Without overtime = 0, overtime = 1	0.405	0.491	691
Work environment	Work environment satisfaction: very dissatisfied = 1, not quite satisfied = 2, neither satisfied nor dissatisfied = 3, relatively satisfied = 4, very satisfied = 5	3.381	0.787	800
Controlled variables
Gender	Female = 0, male = 1	0.537	0.499	801
Age	Unit: year	39.210	10.090	801
Marital status	Unmarried = 0, married = 1	0.863	0.344	801
Hukou status	Agricultural hukou = 0, non-agricultural hukou = 1	0.313	0.464	800
Years of education	Deprived of education = 0, primary school/private school = 6, middle school = 9, high school (ordinary high school, vocational high school, technical school, technical secondary school) = 12, junior college = 15, undergraduate degree = 16, master or above = 19	10.330	3.319	801
Physical health	Very unhealthy = 1, not quite unhealthy = 2, neither healthy nor unhealthy = 3, relatively healthy = 4, very healthy = 5	3.835	0.817	801
Employer type	State-owned enterprises or collective enterprises = 1, private enterprises (private enterprises, private enterprises, foreign investment, joint ventures, etc.) = 0	0.089	0.284	801
Annual income	Post-tax wage income in 2017, take the logarithm	9.531	3.367	777
Labor union	No union = 0, with the union =1	0.310	0.463	574
The Number of acquaintances	No acquaintance = 1, 1–16 acquaintances = 2, more than 17 acquaintances = 3	1.970	0.509	794
Neighborhood support	Very little = 1, less = 2, generally = 3, more = 4, a great many = 5	3.162	0.985	801
Regional characteristics	Eastern region = 1, Non-Eastern region = 0	0.782	0.413	801