Table 2.

Characteristics of subjects (N = 1,559)

	% or mean (SD)
Boys	49.9 (1.3)
Age (yr)
12 or under	38.7 (1.2)
13	23.9 (1.1)
14 or over	37.4 (1.2)
Mean	13.5 (1.3)
Nationality
French	93.1 (0.6)
European immigrants	3.5 (0.5)
Non-European immigrants	3.5 (0.5)
Family structure
Intact	63.0 (1.2)
Divorced/separated parents and reconstructed family	25.1 (1.1)
Single parent and others	11.9 (0.8)
Low parents’ education	48.7 (1.3)
Father’s occupation
Managers, professionals, and intermediate professionals	38.2 (1.2)
Craftsmen, tradesmen, and firm heads	20.1 (1.0)
Service workers and clerks	9.2 (0.7)
Manual workers and other occupations	25.0 (1.1)
Inactive people	7.5 (0.7)
Insufficient income	17.7 (1.0)
Mental health, behavioral, and school difficulties
Last-30-day substance use
Alcohol	35.2 (1.2)
Tobacco	11.2 (0.8)
Cannabis	5.6 (0.6)
Hard drugs	2.8 (0.4)
Obesity	10.6 (0.8)
Depressive symptoms	13.3 (0.9)
Suicide attempts	9.9 (0.8)
Involvement in violence	10.3 (0.8)
Grade repetition	14.7 (0.9)
Low school performance (<10/20)	8.2 (0.7)
Multi-morbidity
CD 0	44.1 (1.3)
CD 1	30.8 (1.2)
CD 2-3	18.4 (1.0)
CD ≥ 4	6.7 (0.6)

CD: number of these outcome variables alcohol use, tobacco use, cannabis use, hard drugs use, obesity, depressive symptoms, suicide attempts, involvement in violence, and low school performance (range 0 to 9).