Descriptive characteristics of the study subjects with and without depression
| Depressed (CES-D≥16) | Non-depressed (CES-D<16) | P value | |
| n (%) | n (%) | ||
| Weight status | 0.006 | ||
| Normal weight | 188 (74.90) | 692 (83.37) | |
| Overweight | 33 (13.15) | 82 (9.88) | |
| Obese | 30 (11.95) | 56 (6.75) | |
| Male | 128 (51.00) | 432 (52.05) | 0.770 |
| Age (year) | 0.041 | ||
| 10 | 83 (33.07) | 257 (30.96) | |
| 11 | 95 (37.85) | 262 (31.57) | |
| 12 | 73 (29.08) | 311 (37.47) | |
| Ethnic minorities* | 51 (20.32) | 65 (7.86) | 0.000 |
| Duration of breast feeding† | 0.411 | ||
| None | 14 (5.58) | 54 (6.15) | |
| 0–6 months | 34 (13.55) | 100 (12.06) | |
| 6–12 months | 113 (45.02) | 370 (44.63) | |
| 12–18 months | 47 (18.73) | 192 (23.16) | |
| >18 months | 43 (17.13) | 113 (13.63) | |
| Birthweight‡ | 0.249 | ||
| Low (≤2.5 kg) | 8 (4.79) | 56 (8.10) | |
| Normal (2.5–4 kg) | 154 (92.22) | 606 (87.70） | |
| High (≥4 kg) | 5 (2.99) | 29 (4.20) | |
| Maternal educational level§ | 0.000 | ||
| No school | 99 (45.83) | 186 (25.10) | |
| Primary school | 57 (26.39) | 197 (26.59) | |
| Middle school | 57 (17.59) | 223 (30.09) | |
| High school or higher | 22 (10.19) | 135 (18.22) | |
| Rural areas | 185 (73.71) | 478 (57.59) | 0.000 |
| Region | 0.000 | ||
| West | 128 (51.00) | 236 (28.43) | |
| East | 69 (27.49) | 254 (30.60) | |
| Central | 43 (17.13) | 223 (26.87) | |
| Northeast | 11 (4.38) | 117 (14.10) | |
| Total | 251 (23.22) | 830 (76.78) |
*Sample size is 1078, †sample size is 1080, ‡sample size is 858, §sample size is 957.
BMI, body mass index; CES-D, Center for Epidemiologic Studies Depression Scales.