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

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.

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.

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.

We analyzed data from 25 samples involving 2479 unipolar depressive and 3936 bipolar disorder subjects (total N=6415) 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-time-ill did not differ between UP and BD subjects, but declined significantly with longer exposure times.

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.