Long-term morbidity in bipolar-I, bipolar-II, and unipolar major depressive disorders

Background: Long-term symptomatic status in persons with major depressive and bipolar disorders treated clinically is not well established, although mood disorders are leading causes of disability worldwide. Aims: To pool data on long-term morbidity, by type and as a proportion of time-at-risk, based on published studies and previously unreported data. Methods: We carried out systematic, computerized literature searches for information on percentage of time in specific morbid states in persons treated clinically and diagnosed with recurrent major depressive or bipolar I or II disorders, and incorporated new data from one of our centers. Results: We analyzed data from 25 samples involving 2479 unipolar depressive and 3936 bipolar disorder subjects (total N¼6415) treated clinically for 9.4 years. Proportions of time ill were surprisingly and similarly high across diagnoses: unipolar depressive (46.0%), bipolar I (43.7%), and bipolar II (43.2%) disorders, and morbidity was predominantly depressive: unipolar (100%), bipolar-II (81.2%), bipolar-I (69.6%). Percent-timeill did not differ between UP and BD subjects, but declined significantly with longer exposure times. Conclusions: The findings indicate that depressive components of all major affective disorders accounted for 86% of the 43–46% of time in affective morbidity that occurred despite availability of effective treatments. These results encourage redoubled efforts to improve treatments for depression and adherence to their long-term use.