Table 4.

Results of chi-square difference tests comparing the corresponding univariate and bivariate probit regression models for each diagnostic group. ^†

Components Tested		CD	ADHD	ODD	ND	AAD	DAD
PC1 + P3
	P3	2.57	0.06	2.23	0.44	1.18	0.01
	PC1	0.02	2.15	0.50	1.37	1.23	1.75
PC2 + P3
	P3	0.17	2.44	0.01	0.03	1.46	0.14
	PC2	2.81	5.69 *	1.67	1.95	5.97 *	1.10
PC3 + P3
	P3	0.86	4.10 *	1.51	2.94	2.22	0.97
	PC3	4.58 *	8.08 **	6.46 **	7.01 **	6.63 **	2.30
PC4 + P3
	P3	0.03	0.25	0.17	0.19	0.01	0.65
	PC4	2.32	1.58	0.96	0.85	2.33	0.01
PC5 + P3
	P3	2.92	0.09	2.07	0.93	1.64	0.35
	PC5	0.03	1.00	0.93	1.87	1.44	1.36
PC3 + P3(mean)
	P3(mean)	0.74	2.63	1.02	2.15	1.22	1.16
	PC3	4.31*	5.91*	5.41*	5.94*	4.99*	2.53
PCs + PC3-TD‡
	PC3-TD	8.76*	1.22	3.62	2.49	4.58	2.84
	PCs	6.47*	1.03	2.18	1.68	3.61	2.55
PC3 + PC3-TD
	PC3-TD	0.15	0.11	0.05	0.23	0.01	0.34
	PC3	4.54*	3.55	8.39**	7.08**	8.45**	2.94

P3(mean)=mean amplitude within a 40ms window centered on the peak of P3

PCs=peak energies of PCs 1, 3, & 5, collectively

PC3-TD=mean amplitude in time-domain within the time range spanned by PC3

Note: df=1 for all tests, except ^‡ df=2.

^*p ≤ .05

^**p ≤ .01

^†A significant result indicates that component accounted for a significant amount of variance in the bivariate model, beyond that accounted for by the other component. A non-significant result indicates that component added no significant discriminative information above that contained in the univariate model.