Table 2.
Cannabis Use Behaviors at the Baseline (N = 43) and at the 1-Month Follow-Up (N = 42)
| Baseline mean (SD) | Follow-up mean (SD) | Dependent samples t-test (baseline vs. follow-up) | % Reporting positive behavior change at follow-up (reductions in substance use behavior) | |
|---|---|---|---|---|
| Past-month cannabis use days (TLFB) | 18.33 (9.93) | 11.05 (11.01) | t(41) = 4.47, p < .001 | 73.8% |
| Cannabis Problems Questionnaire-Adolescent | 16.53 (9.17) | 9.74 (8.01) | t(41) = 5.58, p < .001 | 81% |
| Marijuana Dependence Scale | 3.26 (2.01) | 1.90 (1.56) | t(41) = 2.46, p < .05 | 73.8% |
| Intentions to reduce cannabis use | 13.00 (8.70) | 16.81 (6.88)a | t(41) = −3.54, p < .001 | 21.4% |
| Past-month alcohol use days (TLFB) | 1.74 (2.33) | 1.76 (3.01) | t(41) = 0.00, p = 1.00 | 38.1% |
| Past-month tobacco use days (TLFB) | 13.09 (13.29) | 11.43 (13.13) | t(41) = 0.88, p = .38 | 26.2% |
Note. TLFB = Timeline Followback interview.
a
This measure was collected immediately following the second motivational interviewing session versus the 1-month follow-up.