Abstracts Biological Sciences

Genetic loading and Schizophrenia : relation to course and outcome

by Frances Anne. Champagne

Previous studies have attempted to associate aspects of course and outcome with the schizophrenia genotype. Reliance on a dichotomous familial loading variable as the single indicator of genetic loading has yielded inconsistent results. The goal of the present study was to create a continuous loading variable based on multiple indicators of the schizophrenia genotype (family history of schizophrenia and attention and verbal memory in the 1st degree relatives of the patient) and to determine its association with premorbid adjustment, age at onset, symptoms, and chronicity. Our results suggest that a continuous family history variable predicted problems in premorbid adjustment and an earlier age at onset. Hierarchical regression analysis revealed that verbal memory in the siblings of the patient increased the amount of variance accounted for in premorbid attention problems, over and above that predicted by family history. A "genetic loading" variable based on the incorporation of neuropsychologically impaired siblings into the calculations of family history was significantly correlated with premorbid attention problems.