Neuropsychopharmacology: The Interface Between Genes and Psychiatric Nosology

By Thomas A. Ban

10. Conclusion

The observation that mental illness runs in families received substantial support from findings in epidemiological genetic research. The failure to reveal the mode of inheritance of schizophrenia and manic-depressive disorder with the employment of powerful statistical models led psychiatric geneticists to conclude that the mode of inheritance of these disorders is "complex." However, the inconsistent, conflicting findings in molecular genetic studies of schizophrenia and manic-depressive illness have brought attention to the fact that populations within these diagnostic categories are genetically heterogenous.

Neuropsychopharmacology provides an adequate methodology for the identification of suitable, pharmacologically homogenous forms of illness for genetic research in the different nosologies. Until this is done the use of "nosologic homotypes," identified by the employment of a "nosologic matrix," is an essential prerequisite in genetic research for obtaining interpretable findings.

The "nosologic matrix" may also serve as the starting point for the development of an empirically derived pharmacologically meaningful classification of mental illness. A classification in which the relationship between mental pathology and the pathology of “signal transduction” in the brain is recognized would open up a new perspective in genetic research and in the pharmacotherapy of mental illness.