BIPOLAR DISORDER - FROM FAMILIES TO GENES

Background: Genetic factors are known to contribute to the etiology of bipolar illness, but the actual genetic mechanisms remain to be clari fied. Methods: This paper reviews the research undertaken to establish the generic basis of bipolar illness and to elucidate the nature of i ts genetic predisposition. Results: The presented findings suggest tha t bipolar affective disorder is a heterogeneous condition characterize d by a complex relationship between the genetic susceptibility and the clinical presentation. Linkage studies have generated promising and r eplicated findings on chromosomes 18 and 21. Conclusion: In spite of t he methodological difficulties inherent in the generic study of psychi atric disorders, recent investigations have made important advances an d promise to identify specific susceptibility genes.