Candidate gene studies of some substance related endophenotypes have also been conducted. For example, a study conducted in the Plains Indian sample suggested that EEG alpha power, which was related to co-morbid alcohol dependence and antisocial personality disorder, showed a significant relation with polymorphisms in the serotonin 3B receptor gene (HTR3B; [62]). EEG alpha power also demonstrated a relation with the same COMT polymorphism that was associated with alcoholism and smoking women in the Plains Indian sample [63]. Thus, these studies provide further support for the use of EEG measures as endophenotypes for alcohol and other substance use disorders.
