Table 1. Sociodemographic characteristics of the cohort at age 22.

Variables	Individuals without BD (n=3,526)	Onset of BD in young adulthood (n=268)	p-value
Sex
Male	1,690 (47.9%)	109 (40.7%)	0.026
Female	1,836 (52.1%)	159 (59.3%)
Socioeconomic status
Upper	1,386 (39.3%)	51 (19.0%)	< 0.001
Middle	1,761 (49.9%)	148 (55.2%)
Lower	330 (9.4%)	45 (16.8%)
Missing	49 (1.4%)	24 (9.0%)
Marital status
Married/Stable union	534 (15.1%)	45 (16.8%)	0.664
Divorced/Separated	18 (0.5%)	1 (0.4%)
Single	2,946 (83.6%)	202 (75.4%)
Widowed	1 (0.0%)	0 (0%)
Missing	27 (0.8%)	20 (7.5%)
Years of education
Mean (SD)	9.86 (2.43)	8.67 (2.50)	< 0.001
Median (min, max)	11.0 (0, 12.0)	8.50 (4.00, 12.0)
Missing	30 (0.9%)	20 (7.5%)
Currently working
No	1,045 (29.6%)	92 (34.3%)	0.057
Yes	2,220 (63.0%)	149 (55.6%)
Missing	261 (7.4%)	27 (10.1%)
Lifetime cannabis use
No	2,103 (59.6%)	123 (45.9%)	< 0.001
Yes	1,200 (34.0%)	116 (43.3%)
Missing	223 (6.3%)	29 (10.8%)
Lifetime cocaine use
No	2,794 (79.2%)	168 (62.7%)	< 0.001
Yes	500 (14.2%)	72 (26.9%)
Missing	232 (6.6%)	28 (10.4%)

P-values were calculated by using Student’s t-tests and chi-square tests.