METHODOLOGICAL PROBLEMS IN MOLECULARGENETIC STUDIES IN PSYCHIATRY

Methodological progress, especially due to molecular biology and to the improvement of operationalized psychiatric diagnosis and, in consequence thereof, new programmes for the calculation of linkage have tremendously increased the interest in psychiatric genetics. However, despite of this progress and although with classical genetic methods heterogeneity of psychiatric illnesses is obvious, convincing results are so far lacking. Different causes for the controversial results concerning phenotypes, boundaries of phenotypes, phenocopies, mode of genetic transmission and genotype are discussed.