The role of recurrence and cyclicity in differentiating mood disorder diagnoses
The Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition-Text Revision, distinction between bipolar and unipolar disorders is based on the concept of polarity and discounts the role of cyclicity. Numerous studies have evaluated the relationships between various presentations of bipolar disorder and major depressive disorder (MDD) using external validating factors such as family history, age of onset, chronicity, seasonality, symptom clusters, and treatment response. Patients with more cyclic manifestations of MDD, such as a those with a seasonal pattern or a highly recurrent pattern, are similar in terms of these factors to patients who have bipolar type II disorder and have less in common with the noncyclic unipolar patients. Focusing on the role of cyclicity in the classification of mood disorders may not only lead to a more accurate taxonomy, but may also play an important role in treatment selection.
Saggese, J., Lieberman, D., & Goodwin, F. (2006). The role of recurrence and cyclicity in differentiating mood disorder diagnoses. Primary Psychiatry, 13 (11). Retrieved from https://hsrc.himmelfarb.gwu.edu/smhs_psych_facpubs/1673