Table 1.

Subject characteristics for marijuana nonusers and daily users in adult and adolescent samples based on the past 60 and 90 d, respectively

AdultsAdolescents
Nonusers (N = 29)Daily users (N = 29)SignificanceNonusers (N = 50)Daily users (N = 50)Significance
Sex
    Males16163641
    Females13131490.235
Age (years)27.5 (6.8)27.4 (7.1)0.98516.77 (0.95)16.65 (1.09)0.538
Age range (years)18–5319–5314–1814–18
Educationa13.5 (1.8)13.5 (1.7)0.9669.08 (0.98)9.16 (1.33)0.739
AUDIT score11.9 (7.5)11.9 (6.1)0.9867.38 (7.00)8.10 (5.79)0.577
AUDIT consumption score6.7 (3.0)7.1 (3.0)0.6914.06 (3.40)4.52 (2.87)0.466
Substance useb
    Alcohol (n)
        Drinking days12.31 (21.47)12.97 (18.26)0.869
        Heavy drinking days12.2 (10.8)16.8 (15.0)0.185
        Drinks per drinking day4.6 (2.5)5.7 (3.6)0.2165.19 (5.46)5.42 (5.26)0.831
    Cigarettes (n)
        Smoking days35.2 (28.8)46.1 (25.2)0.127
        Cigarettes per smoking day7.7 (8.3)10.9 (8.2)0.3713.09 (4.66)3.60 (3.70)0.546
    Marijuana (n)
        Smoking days0b60<0.0010b90<0.001
Ethnicity (n)
    Caucasian1314105
    Latino653034
    Native American3313
    African American43
    Asian/Pacific Islander11
    Mixed4134
    Unknown361
Depressionc9.06 (7.79)9.00 (6.20)0.9832.78 (2.81)3.58 (3.53)0.213
Anxietyd8.17 (11.14)12.63 (10.35)0.158
IMPSS
    IMP3.32 (2.47)2.85 (2.03)0.4453.84 (2.22)4.08 (2.10)0.579
    SS7.36 (2.70)6.67 (2.71)0.4447.82 (2.44)7.56 (2.38)0.591
  • Data are mean (SD), unless otherwise indicated. IMP, Impulsivity subscale; SS, sensation-seeking subscale.

  • aHighest grade completed for adults and current grade at study screening for adolescents.

  • bTimeLine Follow Back for past 60 d for adults and variables adapted from White and Labouvie (1989) for the past 90 d for adolescents.

  • cBeck Depression Inventory for adults and Children's Depression Inventory for adolescents.

  • dBeck Anxiety Inventory for adults; no measure available for adolescents.