Table 3.

Statistics for FIRST shape analysis evaluating effect of marijuana between nonusers and daily users

	Structure	Nonusers		Daily users		Variance accounted for by group		Effect size (r)
	Structure	Mean scalar	SD	Mean scalar	SD	F	P	Effect size (r)
Adults	R accumbens	0.023	0.323	−0.023	0.418	2.081	0.791	0.061
	R amygdala	−0.040	0.579	0.040	0.541	0.357	1.000	−0.071
	R hippocampus	−0.048	0.259	0.048	0.374	0.837	0.988	−0.147
	L accumbens	−0.033	0.325	0.033	0.333	1.903	0.780	−0.100
	L amygdala	−0.089	0.367	0.089	0.410	0.653	0.976	−0.223
	L hippocampus	−0.043	0.234	0.043	0.467	0.901	0.993	−0.116
Adolescents	R accumbens	<0.001	0.325	<0.001	0.352	1.516	0.966	0.000
	R amygdala	0.053	0.582	−0.053	0.573	1.777	0.932	−0.181
	R hippocampus	−0.006	0.421	0.006	0.349	4.687	0.352	0.030
	L accumbens	0.037	0.278	−0.037	0.309	1.523	0.988	−0.267
	L amygdala	−0.049	0.383	0.049	0.437	1.174	0.991	0.256
	L hippocampus	0.018	0.295	−0.018	0.323	1.669	0.906	−0.120