Table 10.

Multiple regressions to assess the effects of substance use on outcome

Variable	Ba	β	R2 Change	p
Criterion: MDI
Step 1: age at test	−4.2	−.30	.09	< .0002
Step 2: alcohol use	−7.3	−.21	.01	< .05
Step 3: cocaine use	−8.7	−.24	.06	< .02
Criterion: PDI
Step 1: age at test	0.30	.03	—	< .76
Step 2: alcohol use	−0.44	.02	—	< .89
Step 3: cocaine use	−9.0	−.29	.08	< .01

^aUnstandardized regression coefficient.