Gender differences in factors associated with symptoms of depression among high school students: an examination of the direct and indirect effects of insomnia symptoms and physical activity

Figures & data

Table 1. Sample characteristics and Zero-order (Pearson’s r) correlations for girls (n = 836) and boys (n = 565).

	% Mean (SD)	1	2	3	4	5	6
Girls
(1) Age	17.75 (.98)	–
(2) Non-heterosexual	12.5%	–.01	–
(3) Parent(s) unemployed	18.9%	–.01	.04	–
(4) Insomnia	2.56 (1.48)	.03	.14***	.12**	–
(5) Physical activity	3.25 (.78)	.04	–.11**	–.15***	–.25***	–
(6) Depression	16.97 (10.23)	.05	.21***	.14***	.64***	–.26***	–
(7) BMI (n = 313)	21.92 (3.16)	.05	.04	−.08	.04	.01	-.06
Boys
(1) Age	17.74 (.93)	–
(2) Non-heterosexual	8.1%	.02	–
(3) Parent(s) unemployed	17.7%	.06	.01	–
(4) Insomnia	2.10 (1.34)	–.06	.06	.10*	–
(5) Physical activity	3.36 (.78)	.00	–.14***	–.07	–.13**	–
(6) Depression	12.24 (8.45)	.00	.12**	.11*	.45***	–.14***	–
(7) BMI (n = 254)	22.66 (3.99)	.03	-.03	.02	.02	.07	-.01

Note: *p < .05, **p <.01, ***p < .001.

Figure 1. Predictors of symptoms of depression for the full sample (N = 1401). * p < .05, **p < .01, ***p < .001.

Figure 2. Gender-specific predictors of symptoms of depression. Coefficient are presented as girls (n = 836) / boys (n = 565). *p < .05, **p < .01, ***p < .001.

Table 2. Direct and indirect effects of the predictors on symptoms of depression in the structural model (girls, n = 836 and boys, n = 565).

		Direct effects			Indirect effects through insomnia				Indirect effects through physical activity
	Predictor	β	p	95% CI	β	p	95% CI	RIT	β	p	95% CI	RIT
Girls
	Insomnia	.59	<.001	[ .55, .64]					.02	.004	[ .01, .04]	.04
	Physical activity	–.09	.002	[–.15, .03]	–.15	<.001	[–.19, –.11]	.62
	Parents’ work status	.05	.044	[ .00, .10]
	Sexual orientation	.12	<.001	[ .06, .17]
Boys
	Insomnia	.43	<.001	[ .36, .50]					.01	.16	[–.00, .02]	.02
	Physical activity	–.07	.093	[–.15, .01]	–.06	.004	[–.09, –.02]	.45
	Parents’s work status	.06	.157	[–.02, .15]
	Sexual orientation	.09	.049	[ .00, .17]

Note: RIT = Ratio of indirect to total effect.