Effects of age and parental history of alcoholism on EEG findings in mission Indian children and adolescents.

Background: Many, but not all, Native American tribes have some of the highest rates of alcohol abuse and dependence. Yet, risk factors for the development of problem drinking in these high risk groups remain largely unknown. In primarily Euroamerican populations, electrophysiological variables have been associated with risk for alcoholism. The EEG has a specific developmental time course that has been described in a diverse set of ethnic groups, but it has not been described in Native American youth. In addition, the relationship between EEG development and risk for alcoholism in Indian youth has not been previously studied. Methods: Clinical ratings and spectral characteristics of the resting EEG were investigated in 140 Native American Mission Indian children and adolescents between the ages of 7 and 13 years. The specific aims of the study were to (1) investigate the relationship of age and gender with EEG spectral variables to determine if this population conforms to similar trends from previously published data in other ethnic groups and (2) to determine whether children with a parental history of alcoholism differ from those without alcoholic parents on EEG spectral parameters. Results: No excess of abnormal EEG activity was found in this sample of Native American youth. Age, but not gender, was found to have a significant effect on EEG spectral characteristics with younger children (7–11 years old), having significantly more power in slow activity (0.5–7.5 Hz) and in alpha power (8–12 Hz) as well as slower alpha frequencies than older children (12–13 years old). Consistent with other studies of Native American youth, 66% of the children and adolescents participating in this study had at least one parent who had a lifetime diagnosis of alcohol dependence. However, an ANCOVA that covaried for age and gender revealed no significant differences in power or frequency characteristics of the EEG on the basis of parental history of alcoholism. Conclusions: These studies suggest that this sample of Mission Indian children, despite high levels of parental alcohol dependence and low socioeconomic status, show normal EEG development. As yet, no relationship has been found between any specific EEG phenotype and parental history of alcoholism in this population, however, further EEG maturation may be necessary before any relationships can be fully delineated.