Identifying Predominant Polarity May Be Key to Tailoring Bipolar Disorder Treatment

The clinical characteristics associated with the presence or absence of predominant polarity (PP) in patients with bipolar disorder are significant enough to justify the need for differential treatment, according to study data published in the Journal of Affective Disorders.

Investigators conducted an observational study with the Clinical Outcome and Psycho-Education for Bipolar Disorder, Clinical Outcome Measures Section (COPE-BD) dataset to identify differences in treatment strategies for patients with and without PP. The COPE-BD cohort enrolled patients with bipolar disorder type I, bipolar disorder type II, and major depressive disorder to assess the utility of a software program (COPE.COM for Bipolar Disorder) in mood disorder management. The present analyses only used data from patients with bipolar disorder type I or type II. Per COPE-BD protocol, demographic and clinical variables were assessed at baseline. Predominant polarity was described per the “≥2:1” criterion: To have a predominant pole, patients must have had at least double the number of episodes of one pole compared with the other pole.

The final sample comprised 210 patients with bipolar disorder type I (59.0%) and 146 patients with bipolar disorder type II (41.0%). Among these individuals, 103 (28.9%) presented with predominant polarity: 62 (17.4%) were depressed polarity predominant (DPP) and 41 were manic polarity predominant (MPP). The remaining 253 (71.1%) patients met criteria for bipolar disorder but did not present with a predominant pole.

Compared with those with undetermined polarity, patients with PP experienced more rapid cycling (P <.001). Further, DPP patients experienced more rapid cycling (P <.001), presented with greater anxiety scores on the Hamilton Depression Rating Scales (P =.09, average), and had longer hospitalizations (P =.05) compared with MPP patients. However, MPP patients had a longer illness duration compared with DPP patients (28.00 vs 23.02; P =.08). Patients without PP had an earlier onset of illness (19.96 vs 23.39 years of age; P =.03) and more frequent hypomanic/manic and depressive episodes (both P <.001) compared with patients who met the criteria for PP. Other demographic and clinical variables were not significant between patient diagnostic groups.

The study was limited by its naturalistic and retrospective design, and it did not allow a specific follow-up of polarity over time.

These data suggest a significant difference in clinical variables based on the presence of PP in patients with bipolar disorder. As such, a differential treatment approach may better accommodate the specific symptom profiles of each predominant polarity, although further research is necessary to confirm these findings.

Reference

Sentissi O, Popovic D, Moeglin C, et al. Predominant polarity in bipolar disorder patients: the COPE bipolar sample. J Affect Disord. 2019;250:43-50.