Demographic characteristics of Cohort 2, those 16 year olds who were abstinent for cannabis use at baseline (age 14) but reported 10 or more instances of cannabis use by age 16 (n = 69) and matched controls (n = 69)
| Variable | Cannabis | Control | Statistic |
|---|---|---|---|
| Mean | |||
| Age | 14.43 | 14.50 | t(136) = 0.944 |
| PDS | 2.80 | 2.79 | t(136) = 0.290 |
| VCI | 112.48 | 110.29 | t(136) = 0.859 |
| PRI | 109.16 | 108.26 | t(136) = 0.367 |
| SES | 17.97 | 17.42 | t(136) = 0.835 |
| Total GMV, mm3 | 75,5082.71 | 74,7752.65 | t(136) = 0.647 |
| Lifetime alcohol consumption | 2.33 | 2.29 | t(136) = 0.166 |
| Lifetime nicotine consumption | 1.33 | 1.16 | t(136) = 0.577 |
| Average age of first cannabis use, y | 14.97 | ||
| Summary | |||
| Sex | 74% male | 70% male | U = 2277 |
| Handedness | 93% right handed | 91% right handed | U = 2346 |
| Site 1 | 3 | 7 | U = 2242.5 |
| Site 2 | 11 | 9 | U = 2449.5 |
| Site 3 | 4 | 3 | U = 2415 |
| Site 4 | 8 | 6 | U = 2449.5 |
| Site 5 | 11 | 10 | U = 2415 |
| Site 6 | 8 | 13 | U = 2208 |
| Site 7 | 15 | 10 | U = 2553 |
| Site 8 | 9 | 11 | U = 2311.5 |