Table 5.

Test Statistics for Cholesky Decomposition Model for Major Depressive Disorder Symptoms with Constraints across Ages

Model	−2lnL	df	Δ−2lnL (df)	p value	AIC
1. Age unconstrained model	370.61	66		<.001	238.61
2. Fully age-constrained	684.42	72	313.81(6)	<.001	540.42
3. Constrain A across age	384.93	68	14.32(2)	<.001	248.93
4. Constrain:  A: ages 18 and 21 years	371.58	67	0.97(1)	.32	237.58
5. Constrain C across age	370.64	68	0.03(2)	.99	234.64
6. Constrain E across age	451.71	68	81.10(2)	<.001	315.71
7. Constrain:   A: ages 18 and 21 years   C: all ages	373.15	69	2.54(3)	.47	235.15

Notes. Separate variance-covariance matrices were used for males and females. The unconstrained model is unconstrained across ages but is constrained across sexes. Abbreviations: A=additive genetic effects. C=shared environmental effects. E=nonshared environmental effects. −2lnL= −2 times the log likelihood. AIC=Akaike Information Criteria. Δ−2lnL=differences in 2lnL values between the sex-constrained but age unconstrained model (model 1). Best fitting model is bolded.