Table 1.

Demographic characteristics of Cohort 1, those 14 year olds reporting 1 or 2 instances of cannabis use (n = 46) and matched controls (n = 46)

VariableCannabisControlStatistic
Mean
    Age14.6014.51t(90) = 1.06
    PDS3.042.95t(90) = 0.846
    VCI108.33108.20t(90) = 0.042
    PRI102.85103.77t(90) = 0.345
    SES18.8018.72t(90) = 0.091
    Total GMV, mm374,2955.1272,8559.92t(90) = 1.03
    Lifetime alcohol consumption3.463.52t(90) = 0.214
    Lifetime nicotine consumption2.542.59t(90) = 0.101
    Average age of first cannabis use13.83 years
Summary
    Sex65% male48% maleU = 874
    Handedness87% right handed87% right handedU = 1058
    Site 132U = 1081
    Site 2127U = 1173
    Site 341U = 1127
    Site 468U = 1012
    Site 578U = 1035
    Site 638U = 943
    Site 71112U = 1035
    Site 800
    No. reporting cannabis use in the past 30 d (%)10 (21.74)
    No. reporting cannabis use in the past 7 d (%)6 (13.04)