Postpartum bipolar II disorder ‘may be missed’
MedWire News: Postpartum bipolar II disorder may be mistakenly diagnosed as major depressive disorder, say Canadian and US scientists who make recommendations as to how patients should be treated.
Bipolar postpartum depression is commonly overlooked and mistaken for unipolar major depression. However, while bipolar I disorder is a reliable and relatively stable diagnosis, bipolar II disorder is less easily diagnosed and may be dismissed as a milder form of bipolar I disorder.
To examine the detection, diagnosis, and treatment of bipolar II postpartum depression Verinder Sharma, from the University of Western Ontario in London, Canada, and colleagues conducted a search of the PubMed database and reference lists for relevant articles published between 1998 and 2009.
Estimates of the prevalence of hypomania in non-clinical populations ranged from 9.6% to 20.4% on day 3 postpartum, at an average of approximately 15.0%. Furthermore, almost 20% of patients with hypomanic symptoms at day 3 postpartum developed postpartum depression in one study, with a significant proportion diagnosed with bipolar II disorder or bipolar disorder not otherwise specified (NOS).
Crucially, the team says in the Journal of Affective Disorders that, although there are formal rating scales for assessing bipolar spectrum disorder and unipolar postpartum depression, there are no validated instruments for screening, diagnosing, or monitoring bipolar disorder during pregnancy or postpartum, with even the Highs scale not validated as a diagnostic instrument.
There have only been three randomized controlled trials and six open-label studies of the pharmacologic treatment of postpartum depression, and three studies of the treatment of bipolar disorder during postpartum depression.
While the evidence suggests that postpartum bipolar depression should follow the same guidelines as for non-puerperal bipolar depression, the team says there is a lack of evidence-based treatment options. Women should be monitored closely, they argue, and prophylactic treatment may be considered.
The researchers conclude: “The lack of data on postpartum bipolar II and bipolar disorder NOS is surprising given the high prevalence of hypomanic symptoms immediately after delivery, the unique pharmacologic challenges posed by bipolar depression, and the heightened risk for suicide associated with bipolar spectrum disorder. and illness course that are commonly used to establish the bipolar diathesis of a clinical condition.”
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By Liam Davenport