Sex Differences in Genetic and Environmental Influences on Adolescent Depressive Symptoms: A Meta-Analytic Review

Table 2

Parameter estimates and fit indices for available twin data included in meta-analysis.

	df	χ^2	AIC	Male			Female			Opposite-sex twins
				Child-reported
Full	68	35.28	−100.72	.33 (.15, .52)	.14 (.00, .30)	.52 (.47, .58)	.36 (.21, .51)	.22 (.08, .35)	.43 (.38, .47)	.21 (.00, .05)	1.0
Full	68	35.28	−100.71	.33 (.15, .52)	.14 (.00, .29)	.52 (.46, .58)	.36 (.21, .51)	.22 (.08, .35)	.43 (.38, .47)	.50	.43 (−.08, 1.0)
Common	69	37.70	−100.30	.48 (.39, .54)	.01 (.00, .07)	.51 (.46, .57)	.35 (.19, .51)	.23 (.08, .36)	.43 (.38, .48)	.50	1.0
Scalar	72	53.61	−90.39	.45 (.36, .56)	.07 (.00, .15)	.47 (.43, .51)	.45 (.36, .56)	.07 (.00, .15)	.47 (.43, .51)	.50	1.0
am = af	70	40.19	−99.81	.46 (.35, .53)	.01 (.00, .10)	.53 (.47, .58)	.46 (.35, .53)	.13 (.05, .23)	.41 (.37, .46)	.50	1.0
cm = cf	70	43.55	−96.45	.39 (.27, .50)	.08 (.00, .16)	.53 (.47, .59)	.50 (.39, .60)	.08 (.00, .16)	.42 (.38, .47)	.50	1.0
em = ef	70	43.23	−96.77	.51 (.44, .56)	.02 (.00, .07)	.47 (.43, .51)	.27 (.13, .42)	.27 (.12, .39)	.47 (.43, .51)	.50	1.0
Parent-reported
Full	23	91.00	45.00	.31 (.17, .45)	.34 (.23, .47)	.34 (.30, .39)	.34 (.21, .46)	.37 (.26, .48)	.29 (.26, .33)	.48 (.24, .50)	1.0
Full	23	91.00	45.00	.31 (.17, .44)	.34 (.23, .47)	.34 (.30, .39)	.34 (.21, .46)	.37 (.26, .48)	.29 (.26, .33)	.50	.98 (.83, 1.0)
Common	24	91.04	43.04	.33 (.17, .45)	.34 (.23, .46)	.34 (.30, .39)	.35 (.22, .46)	.36 (.26, .48)	.29 (.26, .33)	.50	1.0
Scalar	27	94.76	40.76	.34 (.26, .42)	.35 (.28, .41)	.31 (.29, .34)	.34 (.27, .41)	.35 (.28, .41)	.31 (.29, .34)	.50	1.0

Note. Full : full sex-limitation model allowing for quantitative sex differences and qualitative genetic sex differences; Full : full sex-limitation model allowing for quantitative sex differences and qualitative shared environmental sex differences; Common: common effects model allowing for quantitative sex differences; Scalar: scalar model; AIC: Akaike’s information criterion; , , and : the proportion of variance in depressive symptoms explained by additive genetic, shared environmental, and nonshared environmental influences, respectively; : the genetic correlation among opposite-sex twin pairs; : the shared environmental correlation among opposite-sex twin pairs; 95% confidence intervals are shown in brackets.