Familial liability to schizophrenia and mood disorders and cognitive impairment in psychosis

Schizophrenia and other psychoses are complex disorders with high rates of cognitive impairment and a considerable degree of genetic and environmental influence on its etiology. Whether cognitive impairment is related to dimensional scores of familial liability is still matter of debate. We conducted a cross-sectional study including 169 patients with psychotic disorders and 26 healthy controls. Attention, memory and executive functions were assessed, and familial loading scores for schizophrenia and mood disorders were calculated. The relationships between familial liability and neuropsychological performance were examined with Spearman׳s correlation coefficients. In addition, patients were classified into three groups by family loading tertiles, and comparisons were performed between the patients in the top and bottom tertiles. Low familial loading scores for schizophrenia showed a significant association with poor executive functioning and delayed visual memory. And these results were also achieved when the subset of psychotic patients in the two extreme tertiles of family loadings of schizophrenia and mood disorders were compared. Low familial liability to schizophrenia seems to be a contributing factor for the severity of cognitive impairment in patients with a broad putative schizophrenia spectrum diagnosis.