Table 1.
Estimated heritabilities (h2)
| Endophenotype | h2 | SE | Covariates contributing to models |
| TTTH1 | 0.40** | 0.07 | ERPAGE**, ERPAGE2†, MXDRNK† |
| TTTH2 | 0.59** | 0.07 | ERPAGE**, ERPAGE2†, SEX‡, MXDRNK‡, SMOKER* |
| TTTH3 | 0.59** | 0.07 | ERPAGE**, ERPAGE2*, SEX§, MXDRNK‡, SMOKER† |
*0.05 ≤ p < 0.10; †p < 0.05; ‡p < 0.01; §p < 0.001; **p < 0.0001