ACCURACIES AND INACCURACIES OF THE FAMILY HISTORY METHOD - A MULTIVARIATE APPROACH

This paper reports on 1459 first-degree relatives of probands with sch izophrenia or affective illness and matched community controls. We sou ght (i) to validate psychiatric diagnoses obtained by family history ( FH) against those obtained by a best estimate (BE) procedure based on personal interview and (ii) to explore the factors influencing the acc uracy of the FH report. We found relatively poor agreement between the FH and BE diagnoses, and the disagreements were influenced by numerou s factors, including gender, psychiatric status of the informant or pr oband's diagnosis. When validated against a BE diagnosis, the overall accuracy of the FH method is relatively poor, and is furthermore subje ct to several biases. Therefore, substituting the FH method for BE dia gnosis may be an important source of error in the investigation of fam ilial/genetic factors in psychiatric disorders.