Table 1.
Prevalence, twin pair probandwise concordance rates and tetrachoric twin pair correlations for cannabis withdrawal and abuse/dependence in 2276 cannabis users.
| Zygosity | Complete pairs |
Single twins |
Withdrawal | Abuse/dependence | ||||
|---|---|---|---|---|---|---|---|---|
| Prevalence % |
Probandwise concordance rates % |
Tetrachoric twin pair correlations ρ 95% CI |
Prevalence % |
Probandwise concordance rates % |
Tetrachoric twin pair correlations ρ 95% CI |
|||
| MZF | 208 | 191 | 9.72 | 54.17 | 0.76 | 15.82 | 61.33 | 0.76 |
| 0.55 – 0.89 | 0.59 – 0.88 | |||||||
| MZM | 98 | 161 | 14.29 | 40.00 | 0.52 | 31.09 | 64.62 | 0.68 |
| 0.13 – 0.79 | 0.43 – 0.85 | |||||||
| DZF | 149 | 174 | 8.90 | 35.71 | 0.56 | 19.70 | 43.33 | 0.49 |
| 0.19 – 0.81 | 0.21 – 0.71 | |||||||
| DZM | 77 | 134 | 15.97 | 36.36 | 0.48 | 31.60 | 48.98 | 0.40 |
| 0.01 – 0.80 | 0.04 – 0.69 | |||||||
| DOS | 132 | M:108 | 20.00 | 21.28 | 0.09 | 38.75 | 26.83 | 0.03 |
| F: 180 | 7.69 | −0.27 – 0.42 | 17.31 | −0.27 – 0.34 | ||||
MZF Monozygotic females. MZM Monozygotic males. DZF Dizygotic females. DZM Dizygotic males. DOS Dizygotic opposite-sex.