Table 2.
Demographic characteristics for MJ users (n=49) at baseline, unless otherwise noted.
| MJ+ALC Early MJ Onset n=27 M(SD) | MJ+ALC Late MJ Onset n= 22 M(SD) | |
|---|---|---|
| Age, Baseline | 17.7 (0.7) | 18.5 (0.6) |
| Age, Year 1.5 | 19.2 (0.7) | 19.9 (1.6) |
| Age, Year 3 | 20.7 (0.7) | 21.5 (0.6) |
| % Male | 59% | 64% |
| % Caucasian | 59% | 77% |
| Grade Point Average | 3.1 (0.8) | 3.2 (0.7) |
| Household Income | 102K (73K) | 172K (125K) |
| % Family History positive for substance use disorder | 46% | 41% |
| Vocabulary T-score | 55.3 (9.5) | 59.5 (8.0) |
| Beck Depression Inventory total, Baseline | 3.9 (5.5) | 2.7 (3.5) |
| Beck Depression Inventory total, Year 1.5 | 2.8 (3.4) | 3.0 (3.7) |
| Beck Depression Inventory total, Year 3 | 3.4 (6.4) | 3.0 (4.4) |
| Spielberger State Anxiety T-score, Baseline | 39.9 (8.2) | 40.1 (8.9) |
| Spielberger State Anxiety T-score, Year 1.5 | 37.5 (6.3) | 37.6 (6.3) |
| Spielberger State Anxiety T-score, Year 3 | 38.8 (8.8) | 39.6 (7.3) |
| Lifetime MJ use episodes, Baseline to Year 3 | 1222.9 (684.2) | 918.7 (442.2) |
| Lifetime alcohol use episodes, Baseline to Year 3 | 618.4 (424.2) | 677.5 (390.2) |
| Lifetime other drug use episodes, Baseline to Year 3 | 103.1 (142.8) | 62.5 (82.2) |
| Average drinks per month, Baseline | 43.6 (51.8) | 53.1 (46.5) |
| Average drinks per month, Year 1.5 | 68.8 (86.8) | 47.3 (34.7) |
| Average drinks per month, Year 3 | 43.7 (53.0) | 60.5 (62.9) |
| Alcohol use episodes from Baseline to Year 1.5 | 219.3 (260.2) | 193.3 (151.8) |
| Alcohol use episodes from Year 1.5 to Year 3 | 165.4 (138.0) | 245.5 (206.4) |
| Heavy episodic drinking episodes Year 1.5 to Year 3a | 138.9 (177.6) | 123.4 (173.8) |
| Average # cigarettes per day Baseline | 1.2 (2.9) | 0.2 (0.5) |
| Average # cigarettes per day, Year 1.5 | 2.1 (4.3) | 0.8 (2.3) |
| Average # cigarettes per day, Year 3 | 1.0 (1.9) | 0.5 (1.3) |
| Average MJ use days per month, Baseline | 13.3 (11.3) | 18.2 (10.0) |
| Average MJ use days per month, Year 1.5 | 12.9 (12.2) | 16.5 (12.2) |
| Average MJ use days per month, Year 3 | 13.8 (11.1) | 12.8 (11.8) |
| Marijuana use episodes from Baseline to Year 1.5 | 282.3 (326.8) | 304.8 (205.9) |
| Marijuana use episodes from Year 1.5 to Year 3 | 263.7 (206.7) | 265.3 (214.6) |
| Days since last MJ use, Year 3 | 83.3 (187.8) | 51.3 (92.9) |
| Days since last alcohol use, Year 3 | 18.6 (17.8) | 10.1 (11.3) |
| Age of onset, regular marijuana use*b | 13.9 (1.3) | 16.7 (0.8) |
| Age on onset, regular alcohol use*b | 15.6 (1.8) | 16.9 (1.7) |
*
p<.05;
a
≥ 4 drinks on one occasion for females and ≥ 5 drinks for males
b
Defined as >1x/week for 52+ weeks