Table 5.
Model of CD and ODD using DSM-IV symptom counts: Model fit statistics, standardized variance components, and genetic and environmental correlations. All models are adjusted for age.
| Model | Parameters | Comparison to full model | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| CD | ODD | Correlations | ||||||||||
| a2 | c2 | e2 | a2 | c2 | e2 | rA | rC | rE | Δχ2 | df | p | |
| 1. Full ACE | .18 (.17–.50) | .40 (.28–.52) | .42 (.38–.46) | .33 (.16–.50) | .16 (.01–.29) | .51 (.47–.56) | .53 (.10–1.00) | .17 (−.29–.63) | .09 (.02–.15) | -- | -- | -- |
| 2. AE Model | .61 (.57–.64) | -- | .39 (.36–.39) | .50 (.45–.54) | -- | .50 (.46–.55) | .30 (.27.38) | -- | .09 (.03–.15) | 41.42 | 3 | <.001 |
| 3. CE Model | -- | .55 (.51–.58) | .45 (.42–.49) | -- | .42 (.38–.46) | .58 (.54–.62) | -- | .29 (.22–.37) | .13 (.08–.18) | 24.24 | 3 | <.001 |
| 4. Orth A (No A cov): Test of genetic distinctness | .15 (.02–.28) | .43 (.31–.54) | .42 (.38–.47) | .29 (.13–.40) | .19 (.04–.32) | .52 (.47–.57) | -- | .51 (.48–.52) | .13 (.07–.18) | 5.58 | 1 | .018 |
| 5. Orth C (No C cov): Test of shared E distinctness | .19 (.07–.32) | .39 (.28–.50) | .42 (.38–.46) | .34 (.18–.51) | .14 (.00–.26) | .51 (.47–.56) | .66 (.43–1.00) | -- | .08 (.01–.09) | 0.77 | 1 | .382 |
| 6. Unidim A: Test of complete genetic overlap | .10 (.10–.24) | .47 (.35–.55) | .43 (.39–.47) | .30 (.12–.48) | .18 (.03–.33) | .52 (.47–.57) | 1.0 | .02 (−.42–.36) | .06 (.002–.13) | 3.01 | 1 | .083 |
| 7. Unidim C: Test of complete shared E overlap | .18 (.05–.32) | .40 (.28–.51) | .42 (.38–.46) | .49 (.43–.54) | .01 (.00–.05) | .50 (.46–.55) | .48 (.05–.99) | 1.0 | .09 (.02–.15) | 4.27 | 1 | .04 |
| 8. Unidim A + Orth C:Test of complete genetic overlap but specific shared E effects | .30 (.14–.47) | .18 (.03–.31) | .52 (.45–.52) | .11 (.05–.22) | .46 (.45–.52) | .43 (.39–.47) | 1.0 | -- | .06 (.002–.12) | 3.02 | 2 | .221 |