Table 2.

Statistics for GLMs for VBM and FreeSurfer analyses evaluating effect of marijuana between non-users and daily users

Analysis method	Structure	Nonusers		Daily users		Variance accounted for by ICV		Effect size (partial η²)	Variance accounted for by group		Effect size (partial η²)
Analysis method	Structure	Estimated marginal mean	SE	Estimated marginal mean	SE	F	p	Effect size (partial η²)	F	p	Effect size (partial η²)
VBM
Adults	Intracranial volume	1,922,899.00	31,018.92	1,913,330.59	31,018.92				0.048	0.828	0.001
	Total brain	1,513,201.81	4119.80	1,515,438.64	4119.80	1971.974	0.000	0.973	0.147	0.703	0.003
	Total gray matter	827,994.23	4163.58	829,365.60	4163.58	484.884	0.000	0.898	0.054	0.817	0.001
	Total white matter	685,207.58	3898.48	686,073.04	3898.48	548.049	0.000	0.909	0.025	0.876	0.000
	R accumbens	311.84	9.04	304.24	9.04	3.296	0.075	0.057	0.353	0.555	0.006
	R amygdala	1453.71	30.34	1463.16	30.34	0.786	0.379	0.014	0.048	0.827	0.001
	R hippocampus	3002.16	38.79	3073.21	38.79	4.396	0.041	0.074	1.677	0.201	0.030
	L accumbens	311.72	9.92	320.46	9.92	4.335	0.042	0.073	0.387	0.536	0.007
	L amygdala	1171.16	26.32	1159.46	26.32	0.881	0.352	0.016	0.099	0.755	0.002
	L hippocampus	3065.53	43.39	3120.25	43.39	2.682	0.107	0.046	0.795	0.377	0.014
	Cerebellum	7835.77	152.16	7834.36	152.16	5.694	0.020	0.094	0.000	0.995	0.000
Adolescents	Intracranial volume	1,920,158.44	24,590.65	1,954,935.94	24,590.65				1.000	0.320	0.010
	Total brain	1,545,844.43	3136.89	1,551,499.77	3136.89	3895.177	<0.001	0.976	1.617	0.207	0.016
	Total gray matter	866,299.03	2737.60	869,082.33	2737.60	1386.205	<0.001	0.935	0.514	0.475	0.005
	Total white matter	679,545.40	2345.95	682,417.44	2345.95	1600.461	<0.001	0.943	0.746	0.390	0.008
	R accumbens	297.45	6.42	300.14	6.42	1.282	0.260	0.013	0.087	0.769	0.001
	R amygdala	1408.51	23.32	1404.80	23.32	0.274	0.602	0.003	0.013	0.911	0.000
	R hippocampus	3055.38	30.73	3018.74	30.73	3.750	0.056	0.037	0.708	0.402	0.007
	L accumbens	302.09	7.74	308.29	7.74	2.268	0.135	0.023	0.320	0.573	0.003
	L amygdala	1124.23	17.72	1141.06	17.72	3.947	0.050	0.039	0.448	0.505	0.005
	L hippocampus	2978.78	30.05	2990.58	30.05	2.048	0.156	0.021	0.077	0.782	0.001
	Cerebellum	7571.77	116.42	7729.65	116.42	3.357	0.070	0.033	0.915	0.341	0.009
FreeSurfer
Adults	Intracranial volume	1,546,121.38	39,078.81	1,536,555.86	39,078.81				0.030	0.863	0.001
	Total brain	1,229,307.07	13,039.49	1,234,999.71	13,039.49	100.313	<0.001	0.654	0.095	0.759	0.002
	Total gray matter	613,116.05	8389.40	615,901.38	8389.40	29.021	<0.001	0.354	0.055	0.815	0.001
	Total white matter	519,152.95	6951.24	522,287.80	6951.24	104.247	<0.001	0.663	0.102	0.751	0.002
	R accumbens	677.13	16.32	672.94	16.32	6.794	0.012	0.110	0.033	0.856	0.001
	R amygdala	1656.83	32.96	1686.17	32.96	15.155	<0.001	0.216	0.396	0.532	0.007
	R hippocampus	4279.82	55.10	4337.39	55.10	44.457	<0.001	0.447	0.546	0.463	0.010
	R cerebellum	53,360.00	827.30	54,256.69	827.30	55.924	<0.001	0.504	0.587	0.447	0.011
	L accumbens	498.65	15.94	521.04	15.94	12.782	0.001	0.189	0.985	0.325	0.018
	L amygdala	1624.13	28.94	1679.18	28.94	15.604	<0.001	0.221	1.809	0.184	0.032
	L hippocampus	4240.54	55.10	4342.42	55.10	40.003	<0.001	0.421	1.709	0.197	0.030
	L cerebellum	52,465.04	777.66	53,511.52	777.66	66.129	<0.001	0.546	0.905	0.346	0.016
Adolescents	Intracranial volume	1,552,515.32	25,781.08	1,616,127.20	25,781.08	—	—	—	3.044	0.084	0.030
	Total brain	1,276,109.88	8077.09	1,272,935.92	8077.09	370.806	<0.001	0.793	0.076	0.783	0.001
	Total gray matter	668,428.50	5354.95	663,327.32	5354.95	158.859	<0.001	0.621	0.447	0.505	0.005
	Total white matter	510,897.02	4981.67	513,508.50	4981.67	228.614	<0.001	0.702	0.135	0.714	0.001
	R accumbens	719.98	14.04	697.28	14.04	15.984	<0.001	0.141	1.288	0.259	0.013
	R amygdala	1713.02	24.17	1703.76	24.17	25.791	<0.001	0.210	0.072	0.789	0.001
	R hippocampus	4355.17	46.01	4360.01	46.01	110.710	<0.001	0.533	0.005	0.941	0.000
	R cerebellum	57,858.92	674.44	56,291.74	674.44	69.453	<0.001	0.417	2.659	0.106	0.027
	L accumbens	573.76	12.40	544.47	12.40	14.288	<0.001	0.128	2.749	0.101	0.028
	L amygdala	1681.57	20.26	1667.17	20.26	39.425	<0.001	0.289	0.249	0.619	0.003
	L hippocampus	4372.76	48.48	4370.36	48.48	106.960	<0.001	0.524	0.001	0.972	0.000
	L cerebellum	57,757.95	685.38	55,647.39	685.38	74.646	<0.001	0.435	4.670	0.033	0.046

R, Right; L, left.