Linkage results for the nicotine dependence diagnosis were then compared to the results from a previous linkage scan of alcohol dependence. None of the regions reported in the previous scan yielded evidence of linkage to nicotine dependence. Additionally, when nicotine dependence was included as a covariate in a linkage analysis of alcohol dependence, LOD scores for the alcohol dependence diagnosis approached 0 in those regions that showed linkage to nicotine dependence in the present report (Table 3). These results provide evidence suggesting that the regions reported here confer risk towards nicotine but not alcohol dependence.
