Current research has revealed that approximately 20 percent of children and 6 percent of adults with bipolar II will develop bipolar I in their lifetime. Researchers from Temple University, the University of Minnesota, the University of Wisconsin-Madison and Northwestern University, conducted a longitudinal study to determine if these findings were accurate and to identify which risk factors increased the likelihood of bipolar II progressing to bipolar I.
The researchers followed 201 college students who were part of the Longitudinal Investigation of Bipolar Spectrum (LIBS) project for four and half years. They were evaluated every four months using the Behavioral Approach System (BAS) and the Behavioral Inhibition System (BIS). The study revealed 57 participants who were originally diagnosed with bipolar disorder not otherwise specified or cyclothymia. Of these, 42.1 percent developed bipolar II and 10.5 percent developed bipolar I. Of the participants who were originally diagnosed with bipolar II, 17.4 percent developed bipolar I during the study. Criteria for diagnosis of bipolar II included the presence of a major depressive episode or a hypomanic episode and an MDE. Criteria for diagnosis of bipolar I was presence of a manic or mixed episode. Of all 201 participants, 21.9 percent had a first degree family relative with a history of some symptom on the bipolar spectrum and the average age of onset of symptoms was 13.
“We found that even among our participants with childhood or adolescent onset of bipolar spectrum disorders, an earlier age of onset was a significant predictor of higher rates of conversion to bipolar I (but not bipolar II) disorder (onset of a manic or mixed episode) in our sample, controlling for length of follow-up, baseline depressive and hypomanic symptoms, and treatment-seeking,” said the researchers. “Perhaps,” they added, “early age of onset reflects a more severe underlying bipolar psychopathology, which leads both to earlier initial appearance of bipolar symptoms and greater likelihood of progressing to full-blown bipolar I.”
Alloy, L. B., Urošević, S., Abramson, L. Y., Jager-Hyman, S., Nusslock, R., Whitehouse, W. G., & Hogan, M. (2011, June 13). Progression Along the Bipolar Spectrum: A Longitudinal Study of Predictors of Conversion From Bipolar Spectrum Conditions to Bipolar I and II Disorders. Journal of Abnormal Psychology. Advance online publication. doi: 10.1037/a0023973
© Copyright 2011 by By John Smith, therapist in Bellingham, Washington. All Rights Reserved. Permission to publish granted to GoodTherapy.org.
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