[Widening the borders of the bipolar disorder: validation of the concept of bipolar spectrum].

It was commonly believed that no more than 1% of the general population has bipolar disorder. New data are beginning to provide confirming evidence for a higher prevalence of up to at least 5%. Several overlapping subtypes of bipolar disorder with hypomanic (rather than manic) features have been described, and more complex evolutive forms of the illness have also received greater clinical attention. The recognition of the entire clinical spectrum of bipolar disorders is of major public health concern because, despite the increasing availability of new treatments, under diagnosis or long delay in diagnosis, and gross under treatment continue to plague our field. Lesser manifestations and subaffective forms usually precede the overt manifestations of the illness in the offspring and biological kin of adult bipolars. In the last decades, a great body of data justifies considerable widening beyond the conservative positions of current nosological classifications, such as DSM IV and ICD10.