Psychosocial disability and work role function compared across the long-term course of bipolar I, bipolar II and unipolar major depressive disorders

The research literature on psychosocial disability and work in mood disorders has either focused on relatively short-term course, or did not consider direct comparisons of these domains across all three of the affective subtypes of bipolar I (BP-I), bipolar II (BP-II), and unipolar major depressive disorders (UP-MDD).

Mean composite measures of psychosocial impairment and months at specific levels of overall and work impairment were compared for 158 BP-I, 133 BP-II, and 358 UP-MDD patients based on semi-structured interviews conducted during 15 years of follow-up in the NIMH Collaborative Depression Study (CDS). These are contrasted with a single month of psychosocial impairment ratings for a sample of 1787 subjects with no current psychiatric disorder.

Patients with mood disorders experienced some degree of disability during the majority of long-term follow-up (54 to 59% of months), including 19 to 23% of months with moderate and 7 to 9% of months with severe overall impairment. Severe disability occurred a substantial percentage of time only in the specific area of work role function. BP-I patients were completely unable to carry out work role functions during 30% of assessed months, which was significantly more than for UP-MDD and BP-II patients (21% and 20%, respectively).

These findings have public health, economic, and clinical importance, and underscore the need to reduce the chronicity and impairment associated with these three prevalent affective disorder subtypes. Interventional research is just beginning to address these challenges.