Predictors of soft bipolarity in depression patients identified
medwireNews: Japanese researchers have identified five clinical features that are independent predictors of "soft bipolarity" in patients experiencing a major depressive episode (MDE).
Minoru Takeshima (Kouseiren Takaoka Hospital, Takaoka City) and Takashi Oka (Zyuzen Hospital, Kanazawa City) found that a family history of bipolar disorders, early age at onset of a first MDE, recurrent MDEs, cyclothymic temperament, and a depressive mixed state (DMX) were independent predictors of soft bipolarity (bipolar II disorder or bipolar disorder not otherwise specified) in patients experiencing an MDE.
"The existence of one or more of these five features in a patient with depression predicted soft bipolarity diagnosis," they explain in the Journal of Affective Disorders.
The findings come from a study of 199 patients, aged a mean of 41 years, who experienced a MDE between 2010 and 2012. Of these, 40.2% were subsequently diagnosed with bipolar II disorder or bipolar disorder not otherwise specified and 59.8% were diagnosed with major depressive disorder.
Using multiple logistic regression analyses, the team identified five clinical features, from a previously proposed list of 12, that significantly predicted soft bipolarity among the patients.
Specifically, recurrent MDEs (>3 versus ≤3), a family history of bipolar disorders in first-degree relatives, a cyclothymic temperament, earlier age at first MDE (<25 vs ≥25 years), and depressive mixed state (≥3 manic/hypomanic symptoms during a MDE that continued for at least 1 week) were significant independent predictors of soft bipolarity, at odds ratios of 11.22, 8.82, 7.32, 6.22, and 5.57, respectively.
Using receiver-operating characteristic analysis, the relationship between bipolarity and these five predictors showed a score for the area under the curve of 0.911, which is considered "highly accurate," say the researchers.
The presence of at least one of the five predictors resulted in the highest sensitivity (92.5%) and good specificity (73.1%) for bipolarity, and the presence of at least two predictors resulted in good sensitivity (70.0%) and the highest specificity (97.5%) for bipolarity.
Takeshima et al conclude that "evaluating these predictors for all patients with depression will be quite helpful in diagnosing soft bipolarity."
They add: "An examination of the outcomes of antidepressant treatment for patients with MDE, who have specific features of soft bipolarity detected in the present study, is needed."
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By Mark Cowen, Senior medwireNews Reporter