Table 1.
Subject Characteristics as a Function of Group Status (n=209).
| OSU (n = 161) | CTL (n = 48) | Univariate ANOVA | |||
|---|---|---|---|---|---|
| M | SD | M | SD | ||
| Demographics | |||||
| Age | 20.8 | 1.5 | 20.9 | 2.1 | F(1, 207) = 0.1, p = .81 |
| Education | 14.3 | 1.2 | 14.5 | 1.5 | F(1, 207) = 0.7, p = .42 |
| Verbal IQ (WTAR) | 108.7 | 7.3 | 109.8 | 7.0 | F(1, 199) = 0.9, p = .34 |
| Alcohol (Typical Drinks/Week) | 20.0 | 14.4 | 4.8 | 3.5 | F(1, 191) = 42.5, p < .001 |
| Alcohol (Typical Days/Week) | 3.2 | 1.6 | 1.5 | 0.7 | F(1, 191) = 38.1, p < .001 |
| Nicotine (Cigarettes/Day) | 2.7 | 4.4 | 0.5 | 2.9 | F(1, 207) = 10.7, p < .001 |
| Nicotine (Typical Days/Week) | 2.6 | 3.2 | 0.2 | 1.1 | F(1, 207) = 26.0, p < .001 |
| Lifetime Drug Use | |||||
| Cocaine | 22.4 | 38.4 | 0.0 | 0.0 | N/A |
| Prescription Stimulant | 22.2 | 51.1 | 0.0 | 0.0 | N/A |
| Cannabis | 914.0 | 1416.7 | 10.3 | 25.9 | F(1, 207) = 19.5, p < .001* |
Note. OSU = occasional stimulant users. CTL = control subjects. ANOVA = Analysis of variance. IQ = Intelligence Quotient. WTAR = Wechsler Test of Adult Reading. DSM-IV = Diagnosis and Statistical Manual of Mental Disorders IV. For a minority of subjects, data were not collected for verbal IQ (n = 8) and weekly alcohol use (n = 16).
*
ANOVAs computed using natural log transformed +1 values (due to non-normal distributions) replicated results for raw data.