Table 1.
Participant demographic, substance use, and mental health characteristics by assessment wave.
| Assessment Wave | |||||
|---|---|---|---|---|---|
| T1 (N = 401) | T2 (N = 391) | T3 (N = 383) | T4 (N = 380) | T5 (N = 387) | |
| Demographics (M, SD) | |||||
| Age | 15.40 (.72) | 15.96 (.81) | 16.38 (.71) | 16.92 (.78) | 17.39 (.75) |
| Sex (% Male) | 54.1 | 53.7 | 54.0 | 53.9 | 54.0 |
| Race (% White) | 76.8 | 76.7 | 76.2 | 76.8 | 77.0 |
| Ethnicity (% Hispanic/Latino) | 89.8 | 89.5 | 89.3 | 89.7 | 89.7 |
| Years of Education | 9.11 (.84) | 9.74 (.90) | 10.08 (.85) | 10.73 (.88) | 11.07 (.84) |
| Years of Maternal Education | 14.23 (2.49) | ||||
| WRAT-4 Reading Standard Score | 108.31 (14.73) | ||||
| Substance Use Characteristics | |||||
| Past 6-month Cannabis Use Days (Md, [IQR]) | 6.00 [.00, 30.00] | 8.00 [.00, 49.00] | 10.00 [.00, 73.00] | 7.00 [.00, 84.50] | 14.00 [.00. 105.00] |
| Past 6-month Alcohol Days (Md, [IQR]) | 1.00 [.00, 5.00] | 2.00 [.00, 8.00] | 3.00 [1.00, 9.00] | 3.00 [.00, 11.00] | 4.00 [1.00, 15.00] |
| Past 6-month Nicotine Days (Md, [IQR]) | .00 [.00, 1.00] | .00 [.00, .00] | .00 [.00, 1.00] | .00 [.00, .00] | .00 [.00, 2.00] |
| Lifetime Cannabis Use Days (Md, [IQR]) | 21.00 [1.00, 144.50] | 36.00 [2.00, 186.00 | 62.00 [3.00, 266.25] | 82.00 [4.00, 350.00] | 108.00 [8.50, 483.00] |
| Lifetime Cannabis Use Amount (grams; (Md, [IQR]) | 9.00 [.25, 93.65] | 19.00 [.35, 145.50] | 32.30 [.70, 207.66] | 42.27 [.97, 252.27] | 61.07 [2.83, 354.71] |
| Days/Month of Cannabis Use (M, SD) | 4.58 (7.59) | 5.37 (7.83) | 6.93 (9.55) | 7.26 (10.14) | 8.71 (10.86) |
| 3x/Week to Daily Cannabis Use (%) | 15.7 | 18.9 | 25.6 | 26.3 | 32.3 |
| Near Daily/Daily Cannabis Use (%) | 9.5 | 11.3 | 18.0 | 20.0 | 25.3 |
| Current Cannabis Use Disorder (%) | 13.2 | 11.5 | 19.6 | 17.6 | 23.3 |
| Lifetime Cannabis Use Disorder (%) | 22.2 | 29.4 | 37.8 | 42.4 | 47.8 |
| Mental Health (M, SD) | |||||
| DASS Depression z-score | −.31 (.86) | −.38 (.80) | −.29 (.95) | −.44 (.77) | −.34 (.90) |
| DASS Anxiety z-score | .08 (1.21) | .14 (1.20) | −.08 (1.23) | −.08 (1.10) | −.18 (1.18) |
| Current Internalizing Disorder (%) | 5.5 | - | 4.5 | - | 4.7 |
| Current Externalizing Disorder (%) | 11.0 | - | 7.7 | - | 5.7 |
| Lifetime Internalizing Disorder (%) | - | - | - | - | 25.7 |
| Lifetime Externalizing Disorder (%) | - | - | - | - | 19.2 |
Note: M = Mean; SD = Standard Deviation; Md = Median; IQR = Interquartile range; WRAT-4 = Wide Range Achievement Test, 4th Edition; DASS = Depression, Anxiety, and Stress Scale, 21-Item Form. Participants were classified as having an internalizing disorder if they met diagnostic criteria for generalized anxiety disorder, panic disorder, obsessive compulsive disorder, major depression, dysthymia, or mania. Participants were classified as having an externalizing disorder if they met diagnostic criteria for attention deficit/hyperactivity disorder, oppositional defiant disorder, or conduct disorder. “Near daily” was defined as using on most days.