Table A1.
Twin-sibling model-fitting results for bivariate models for symptoms of disordered gambling (DG) and measures of major depression (MD), alcohol, caffeine and cigarette use and nicotine dependence (ND)
| Sex effects |
||||||
|---|---|---|---|---|---|---|
| Model | Description | Qualitative | Quantitative | Δ-2LL | Δdf | ΔAIC |
| MD and symptoms of DG using twin pairs and non-twin sibling pairs | ||||||
| Ia | ACET | + | + | – | – | – |
| II | ACET | + | – | +19.801 | +10 | –0.199 |
| III | ACET | – | – | +19.827 | +11 | –2.173 |
| IV | ACE | – | – | +21.251 | +14 | –6.749 |
| V | CE | – | – | +47.086 | +17 | +13.086 |
| VI | AE | – | – | +22.132 | +17 | –11.868 |
| Alcohol and symptoms of DG using twin pairs and non-twin sibling pairs | ||||||
| Ib | ACET | + | + | – | – | – |
| II | ACET | + | – | +4.709 | +10 | –15.291 |
| III | ACET | – | – | +4.723 | +11 | –17.277 |
| IV | ACE | – | – | +5.766 | +14 | –22.234 |
| V | CE | – | – | +44.073 | +17 | +10.073 |
| VI | AE | – | – | +47.773 | +17 | +13.773 |
| VII | ACE-AE | – | – | +18.508 | +16 | –13.492 |
| Caffeine and symptoms of DG using twin pairs and non-twin sibling pairs | ||||||
| Ic | ACET | + | + | – | – | – |
| II | ACET | + | – | +21.704 | +10 | +1.704 |
| III | ACET | – | – | +21.708 | +11 | –0.292 |
| IV | ACE | – | – | +21.910 | +14 | –6.090 |
| V | CE | – | – | +51.753 | +17 | +17.753 |
| VI | AE | – | – | +31.488 | +17 | –2.512 |
| VII | ACE-AE | – | – | +23.589 | + 16 | –8.411 |
| Cigarettes and symptoms of DG using twin pairs and non-twin sibling pairs | ||||||
| Id | ACET | + | + | – | – | – |
| II | ACET | + | – | +10.738 | +10 | –9.262 |
| III | ACET | – | – | +12.233 | +11 | –9.767 |
| IV | ACE | – | – | +13.452 | +14 | –14.548 |
| V | CE | – | – | +57.175 | +17 | +23.175 |
| VI | AE | – | – | +18.310 | + 17 | –15.690 |
| ND and symptoms of DG using twin pairs and non-twin sibling pairs | ||||||
| Ie | ACET | + | + | – | – | – |
| II | ACET | + | – | +16.806 | +10 | –3.194 |
| III | ACET | – | – | +17.076 | +11 | –4.924 |
| IV | ACE | – | – | +18.100 | +14 | –9.900 |
| V | CE | – | – | +47.084 | +17 | +13.084 |
| VI | AE | – | – | +25.127 | +17 | –8.873 |
| VII | ACE-AE | – | – | +23.672 | +16 | –8.328 |
A, Additive genetic effects; C, shared environment; E, individual specific environment; T, special twin environment; df, degrees of freedom; AIC, Akaike's Information Criterion; LL, log likelihood.
a
–2LL =3621.396, df = 3474, AIC =–3326.604.
b
–2LL = 5476.595, df = 3445, AIC =–1413.405.
c
–2LL = 6493.133, df = 3469, AIC = –444.867.
d
–2LL= 3410.396, df = 3471, AIC= –3531.604.
e
–2LL = 3195.931, df = 3471, AIC = –3746.069.
Best-fit models are shown in bold.