Background: The P3b component of the event-related potential (ERP) has frequently been reported to be reduced in children and adolescents at high risk for developing alcoholism relative to control children and adolescents without familial loading for alcohol dependence. P300 amplitude changes during development for all children. Previously it has been shown that high-risk offspring display a pattern in which the amplitude is lower at age 8 with a smaller rate of change during adolescence.
Methods: Admixture analysis was applied to data obtained for those children and adolescents having five or more annual assessments of ERPs to determine if multiple P3b growth patterns exist. The P3b amplitude patterns obtained were related to risk status, concurrent presence of childhood psychopathology (internalizing or externalizing), and age of onset to develop a diagnosis.
Results: A pattern characterized by lower P3b amplitude at study entry and a slower rate of change during child and adolescent development (pattern 3) was most often associated with high-risk status in boys and high-risk status in combination with the presence of a childhood diagnosis in girls. Pattern 3 was significantly related to the overall presence of childhood psychopathology (internalizing or externalizing) and to the presence of an Axis I diagnosis at young adult follow-up.
Conclusions: The developmental pattern previously described for offspring at high risk for developing alcoholism because of their familial/genetic background was confirmed. Admixture analysis has refined this observation and suggests that among all children and adolescents tested, three developmental patterns can be identified, one of which is most often seen in association with male high-risk children and adolescents.