In summary, in view of the a priori evidence for the validity of the ADH association finding and the independent replication, the present study has demonstrated the potential of the GWAS approach, which could lead to many more valuable findings if pursued in sufficiently large and homogeneous samples. The finding of a polygenic component is consistent with findings for other psychiatric disorders, and suggests the existence of a continuum of genetic effects, and that a host of susceptibility genes still await identification.
