Table 2. Demographic Characteristics for all Subjects.
| Demographic characteristics | Overall |
|---|---|
| N | 159 |
| Age (years) (mean±SEM) | 22.8+3.6 |
| Gender (% female) | 44 |
| BMI (mean±SEM) | 22.7+2.2 |
| Education (years) (mean±SEM) | 15.1+1.4 |
| Current substance use | |
| Alcohol (drinks/week) (mean±SEM) | 4.5+3.7 |
| Cigarettes (cigarettes/week) (mean±SEM) | 0.8+1.8 |
| Caffeine (cups/day) (mean±SEM) | 7.3+7.0 |
| Marijuana (times/month) (mean±SEM) | 0.9+2.3 |
| Lifetime substance use | |
| Stimulants (ever used) (%) | 51.6 |
| Sedatives (ever used) (%) | 6.3 |
| Opiates (ever used) (%) | 22.0 |
| Marijuana (ever used) (%) | 44.2 |
| Hallucinogens (ever used) (%) | 28.9 |
| Inhalants (ever used) (%) | 9.4 |
Comparisons across genoptype groups for all FAAH SNPs were made using one-way ANOVA for continuous data and χ2-test for frequency data; none of these tests yielded significant results.