The Impact of Sleep Timing, Sleep Duration, and Sleep Quality on Depressive Symptoms and Suicidal Ideation amongst Japanese Freshmen: The EQUSITE Study

Table 1

The characteristics of study participants with and without the depressive symptoms.

	Total	Nondepressed ()	Depressed ()	value
	(%)	(%)	(%)
Age, years (means ± standard deviations)	18.4 1.1	18.4 1.1	18.4 1.1	0.28
Gender				0.40
Male	1385 (69.5)	1026 (69.1)	359 (70.8)
Female	607 (30.5)	459 (30.9)	148 (29.2)
Weight category				0.36
Normal weight (BMI < 25 kg/m^2)	1786 (89.7)	1326 (89.3)	460 (90.7)
Overweight (BMI ≥ 25 kg/m^2)	206 (10.3)	159 (10.7)	47 (9.3)
Exercise habits				<0.01
Irregular	724 (36.3)	494 (33.3)	230 (45.4)
Regular	1268 (63.7)	991 (66.7)	277 (54.6)
Exercise duration
<1 h	1109 (55.7)	784 (52.8)	325 (64.1)	<0.01
≥1 h	883 (44.3)	701 (47.2)	182 (35.9)
Breakfast habits				<0.01
Irregular	466 (23.4)	315 (21.2)	151 (29.8)
Regular	1526 (76.6)	1170 (78.8)	356 (70.2)
Smoking habits				0.05
Never	1969 (98.8)	1472 (99.1)	497 (98.0)
Sometimes	23 (1.2)	13 (0.9)	10 (2.0)
Drinking habits				0.98
Never	1229 (61.7)	916 (61.7)	313 (61.7)
Once or more per week	763 (38.3)	569 (38.3)	194 (38.3)
Financial difficulty				0.02
No	1761 (88.4)	1327 (89.4)	434 (85.6)
Yes	231 (11.6)	158 (10.6)	73 (14.4)
Living condition
Living alone	1297 (65.1)	958 (64.5)	339 (66.9)	0.13
Living in dormitory	136 (6.8)	95 (6.4)	41 (8.1)
Living with parents	559 (28.1)	432 (29.1)	127 (25.0)
Commute time
<30 min	893 (44.8)	648 (43.6)	245 (48.3)	0.07
30 min	1099 (55.2)	837 (56.4)	262 (51.7)
Part-time job				0.06
No	1593 (80.0)	1173 (79.0)	420 (82.8)
Yes	399 (20.0)	312 (21.0)	87 (4.4)
Suicidal ideation
No	1877 (94.2)	1452 (97.8)	425 (21.3)	<0.01
Yes	115 (5.8)	33 (2.2)	82 (4.1)