Table 5.
Three definitions of cannabis withdrawal as predictors of DSM-IV cannabis dependence symptom count at 1-year follow-up (n = 197).
| Baseline predictor | B | SE B | β |
|---|---|---|---|
| Sex | 0.53 | 0.23 | 0.17* |
| Age | 0.04 | 0.10 | 0.03 |
| Ethnicity | 0.94 | 0.35 | 0.20** |
| SES | −0.19 | 0.10 | −0.14 |
| Past year alcohol diagnosis (yes/no) | −0.06 | 0.14 | −0.03 |
| Past year conduct disorder symptom count | 0.06 | 0.06 | 0.08 |
| Life-time number of other drugs used | 0.06 | 0.06 | 0.08 |
| Past year depression diagnosis (yes/no) | −0.10 | 0.23 | −0.03 |
| Past year anxiety diagnosis (yes/no) | 0.13 | 0.34 | 0.03 |
| Past year ADHD diagnosis (yes/no) | 0.30 | 0.27 | 0.08 |
| Past year frequency of cannabis use | 0.08 | 0.06 | 0.10 |
| Two-symptom withdrawal | 0.31 | 0.22 | 0.10 |
| Sex | 0.54 | 0.22 | 0.17* |
| Age | 0.03 | 0.09 | 0.03 |
| Ethnicity | 0.93 | 0.34 | 0.20** |
| SES | −0.18 | 0.10 | −0.14 |
| Past year alcohol diagnosis (yes/no) | −0.12 | 0.14 | −0.03 |
| Past year conduct disorder symptom count | 0.04 | 0.06 | 0.08 |
| Life-time number of other drugs used | 0.04 | 0.06 | 0.08 |
| Past year depression diagnosis (yes/no) | −0.12 | 0.23 | −0.03 |
| Past year anxiety diagnosis (yes/no) | 0.18 | 0.34 | 0.03 |
| Past year ADHD diagnosis (yes/no) | 0.24 | 0.27 | 0.08 |
| Past year frequency of cannabis use | 0.07 | 0.06 | 0.10 |
| Four-symptom withdrawal | 0.79 | 0.29 | 0.18** |
| Sex | 0.56 | 0.22 | 0.18* |
| Age | 0.03 | 0.09 | 0.02 |
| Ethnicity | 0.92 | 0.34 | 0.20** |
| SES | −0.17 | 0.10 | −0.12 |
| Past year alcohol diagnosis (yes/no) | −0.11 | 0.13 | −0.06 |
| Past year conduct disorder symptom count | 0.04 | 0.06 | 0.06 |
| Life-time number of other drugs used | 0.04 | 0.06 | 0.05 |
| Past year depression diagnosis (yes/no) | −0.16 | 0.23 | −0.05 |
| Past year anxiety diagnosis (yes/no) | 0.21 | 0.34 | 0.04 |
| Past year ADHD diagnosis (yes/no) | 0.18 | 0.27 | 0.05 |
| Past year frequency of cannabis use | 0.07 | 0.06 | 0.09 |
| LCA high severity withdrawal | 0.90 | 0.29 | 0.24** |
Predictors were entered simultaneously in all regression analyses. SES: socio-economic status; ADHD: attention deficit hyperactivity disorder; LCA: latent class analysis. ‘LCA high severity’ definition distinguishes between two groups: youth in the ‘high severity’ cannabis withdrawal class versus youth in ‘moderate’ and ‘low’ severity cannabis withdrawal classes; B: unstandardized beta weight; SE B: standard error of the unstandardized beta weight; β: standardized beta weight (indication of effect size).
P < 0.05;
P < 0.01.
Effect sizes for the four-symptom and LCA high severity withdrawal definition are generally considered ‘small effects’ [39]. Results using the number of cannabis abuse and dependence symptoms at 1 year generated similar results (i.e. only the four-symptom and LCA high severity definitions predicted the number of cannabis abuse and dependence symptoms at 1-year follow-up).