MedWire News: Many patients with bipolar I disorder (BD I) continue to experience functioning impairments 15 years after first being hospitalized for a manic episode, US research shows.
"Impaired psychosocial functioning has become increasingly recognized in bipolar disorder," observe Joseph Goldberg (Mount Sinai School of Medicine, New York) and Martin Harrow (University of Illinois, Chicago) in the journal Bipolar Disorders.
They add: "Problems with work adjustment and global outcome often persist for many months after syndromic recovery from an index manic episode. However, most prospective longitudinal studies have been of relatively short duration (ie, <5 years), and little is known about functional disability at longer-term follow-up."
To address this, the researchers studied 46 BD I patients and 49 with unipolar nonpsychotic depression who were followed-up 15 years after first being hospitalized for a mood episode.
The participants, who were aged a mean of 39.7 and 37.9 years, respectively, at follow-up, were assessed for global functioning using the Levenstein, Klein, Pollack (LKP) Scale - an eight-point clinician-rated scale that incorporates information regarding past-year symptoms, rehospitalization, role functioning, self-support, and adaptation to life stresses. A good functional outcome was defined as a score of 1-2 on the LKP Scale, with higher scores reflecting progressive levels of poorer global functioning.
Work functioning and social adjustment were each rated using separate Likert-type scales, with scores of 0 reflecting very poor work or social adjustment and scores of 4 reflecting good work functioning and social adjustment.
The researchers found that just 35% of BD I patients had good global functioning at the 15-year follow-up assessment compared with 73% of those with unipolar depression.
BD I patients also had significantly poorer work functioning ratings than unipolar patients, at 2.3 versus 3.4. However, there were no significant differences regarding social adjustment between the groups at follow-up.
Logistic regression analysis revealed that patients with unipolar depression were 7.9 times more likely to have good global functioning at follow-up than BD I patients. The absence of a depressive episode in the past year was also associated with good global functioning at follow-up in both groups, at an odds ratio of 5.6 compared with the presence of a past-year depressive episode.
In addition, the team found that subsyndromal depression was significantly associated with poorer global, work, and social functioning in BD I, but not unipolar depression patients.
Goldberg and Harrow conclude: "Long-term outcome for patients with BD I treated under ordinary conditions was significantly more impaired than in nonpsychotic unipolar depression."
They add: "The treatment of depression to full and sustained remission continues to pose a critical link to long-term recovery in bipolar disorder."
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