The impact of bipolar disorder during pregnancy has been hotly contended among the research community. Now, a new study from Lawson Health Research Institute and Western University is sorting out the debate and calling for more targeted, prospective research.
Bipolar disorder is characterized by depression, hypomania, or mania. It is most common among women, and its episodes are often concentrated during the height of the reproductive years.
Bipolar disorder can lead to suicide, infanticide, and increased risk for psychiatric hospitalization during the postpartum period. During pregnancy, though, the impact is unclear. Through a comprehensive literature review, Dr. Verinder Sharma and his team sought to clearly define what scientists already knew about bipolar disorder during pregnancy, and where they should look next.
Despite contradictory findings, their review suggests pregnancy could have a positive impact on bipolar disorder. Throughout the literature, bipolar II disorder was either uncommon or in remission during pregnancy. Women already diagnosed with bipolar disorder had fewer and shorter episodes while pregnant. Pregnant women also had a lower risk of any other mood disorder than non-pregnant women.
However, the impact of mood stabilizer medications has complicated much of the existing data. In the literature, bipolar disorder is often misdiagnosed as depression, and antidepressants are prescribed as treatment. These medications are known to make bipolar symptoms worse. Similarly, many women taking mood stabilizers discontinue their prescriptions to avoid potential side effects on their unborn babies. This rapid break appears to provoke bipolar episodes.
These circumstances have made it challenging for scientists to separate the impact of the drugs from the impact of the disorder. To make a clear judgment, Dr. Sharma is calling for large, multicenter, prospective studies that specifically address the natural course of the disorder.
"There is no period in a woman's life when the risk of relapse of bipolar disorder is as high as in the postpartum period. This is in sharp contrast to pregnancy, when women may experience an improvement in their symptoms," he says. "If we fail to understand the effect of pregnancy on bipolar disorder, we will fail to understand bipolar disorder."
The study was funded by the Ontario Mental Health Foundation, and will be published online tomorrow in The Journal of Clinical Psychiatry.