Sharma, Verinder; Burt, Vivien K, MD, PhD; Ritchie, Hendrica L, MD. The American Journal of Psychiatry166. 11 (Nov 2009): 1217-21.
Bipolarity and the Postpartum Period
Bipolar spectrum disorder generally includes bipolar I disorder, bipolar II disorder, and bipolar disorder not otherwise specified (1). Bipolar I disorder is characterized by recurrent episodes of mania and depression, while bipolar II disorder is defined as recurrent episodes of depression and hypomania. The illness course inbipolar disorder not otherwise specified is also punctuated with manic and depressive symptoms, but the disorder does not reach the DSM -IV threshold criteria for bipolar I or II disorder. There is accumulating evidence that the majority of bipolarity exists beyond the realm of bipolar I disorder. The U.S. National Comorbidity Survey Replication Study reported lifetime prevalence estimates of 1.0% for bipolar 1 disorder, 1.1% for bipolar II disorder, and 2.4% for bipolar disorder not otherwise specified (2).
Despite the combined high prevalence of bipolar II disorder and bipolar disorder not otherwise specified, research on postpartum mood disorders has focused primarily on major depressive disorder, mania, and puerperal psychosis. While the nosological status of postpartum psychosis remains a topic of debate, it is usually a manifestation of bipolar disorder triggered by childbirth. The study of postpartum bipolarity beyondbipolar I disorder has been largely ignored; consequently, uhere are scant data on the prevalence of depressive presentations in bipolar II disorder and bipolar disorder not otherwise specified. Freeman et al. [3) reported that 67% of 30 women with bipolar 1 and II disorder had a postpartum mood episode within 1 month of delivery; in the eight women who had experienced episodes following their first delivery, the recurrence rate following a subsequent delivery was 100%. Identified