Table 2.

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

Analysis methodStructureNonusersDaily usersVariance accounted for by ICVEffect size (partial η2)Variance accounted for by groupEffect size (partial η2)
Estimated marginal meanSEEstimated marginal meanSEFpFp
VBM
    AdultsIntracranial volume1,922,899.0031,018.921,913,330.5931,018.920.0480.8280.001
Total brain1,513,201.814119.801,515,438.644119.801971.9740.0000.9730.1470.7030.003
Total gray matter827,994.234163.58829,365.604163.58484.8840.0000.8980.0540.8170.001
Total white matter685,207.583898.48686,073.043898.48548.0490.0000.9090.0250.8760.000
R accumbens311.849.04304.249.043.2960.0750.0570.3530.5550.006
R amygdala1453.7130.341463.1630.340.7860.3790.0140.0480.8270.001
R hippocampus3002.1638.793073.2138.794.3960.0410.0741.6770.2010.030
L accumbens311.729.92320.469.924.3350.0420.0730.3870.5360.007
L amygdala1171.1626.321159.4626.320.8810.3520.0160.0990.7550.002
L hippocampus3065.5343.393120.2543.392.6820.1070.0460.7950.3770.014
Cerebellum7835.77152.167834.36152.165.6940.0200.0940.0000.9950.000
    AdolescentsIntracranial volume1,920,158.4424,590.651,954,935.9424,590.651.0000.3200.010
Total brain1,545,844.433136.891,551,499.773136.893895.177<0.0010.9761.6170.2070.016
Total gray matter866,299.032737.60869,082.332737.601386.205<0.0010.9350.5140.4750.005
Total white matter679,545.402345.95682,417.442345.951600.461<0.0010.9430.7460.3900.008
R accumbens297.456.42300.146.421.2820.2600.0130.0870.7690.001
R amygdala1408.5123.321404.8023.320.2740.6020.0030.0130.9110.000
R hippocampus3055.3830.733018.7430.733.7500.0560.0370.7080.4020.007
L accumbens302.097.74308.297.742.2680.1350.0230.3200.5730.003
L amygdala1124.2317.721141.0617.723.9470.0500.0390.4480.5050.005
L hippocampus2978.7830.052990.5830.052.0480.1560.0210.0770.7820.001
Cerebellum7571.77116.427729.65116.423.3570.0700.0330.9150.3410.009
FreeSurfer
    AdultsIntracranial volume1,546,121.3839,078.811,536,555.8639,078.810.0300.8630.001
Total brain1,229,307.0713,039.491,234,999.7113,039.49100.313<0.0010.6540.0950.7590.002
Total gray matter613,116.058389.40615,901.388389.4029.021<0.0010.3540.0550.8150.001
Total white matter519,152.956951.24522,287.806951.24104.247<0.0010.6630.1020.7510.002
R accumbens677.1316.32672.9416.326.7940.0120.1100.0330.8560.001
R amygdala1656.8332.961686.1732.9615.155<0.0010.2160.3960.5320.007
R hippocampus4279.8255.104337.3955.1044.457<0.0010.4470.5460.4630.010
R cerebellum53,360.00827.3054,256.69827.3055.924<0.0010.5040.5870.4470.011
L accumbens498.6515.94521.0415.9412.7820.0010.1890.9850.3250.018
L amygdala1624.1328.941679.1828.9415.604<0.0010.2211.8090.1840.032
L hippocampus4240.5455.104342.4255.1040.003<0.0010.4211.7090.1970.030
L cerebellum52,465.04777.6653,511.52777.6666.129<0.0010.5460.9050.3460.016
    AdolescentsIntracranial volume1,552,515.3225,781.081,616,127.2025,781.083.0440.0840.030
Total brain1,276,109.888077.091,272,935.928077.09370.806<0.0010.7930.0760.7830.001
Total gray matter668,428.505354.95663,327.325354.95158.859<0.0010.6210.4470.5050.005
Total white matter510,897.024981.67513,508.504981.67228.614<0.0010.7020.1350.7140.001
R accumbens719.9814.04697.2814.0415.984<0.0010.1411.2880.2590.013
R amygdala1713.0224.171703.7624.1725.791<0.0010.2100.0720.7890.001
R hippocampus4355.1746.014360.0146.01110.710<0.0010.5330.0050.9410.000
R cerebellum57,858.92674.4456,291.74674.4469.453<0.0010.4172.6590.1060.027
L accumbens573.7612.40544.4712.4014.288<0.0010.1282.7490.1010.028
L amygdala1681.5720.261667.1720.2639.425<0.0010.2890.2490.6190.003
L hippocampus4372.7648.484370.3648.48106.960<0.0010.5240.0010.9720.000
L cerebellum57,757.95685.3855,647.39685.3874.646<0.0010.4354.6700.0330.046
  • R, Right; L, left.