Management Issues During Pregnancy in Women With Bipolar Disorder

To the Editor: We read with interest the article by Clark et al. (1) on lamotrigine dosing in pregnant patients with bipolar I disorder. The authors report on the use of lamotrigine in eight patients with bipolar disorder, six of whom received concomitant psychotropic drugs including four women who were taking antidepressant drugs. Dosage adjustments of lamotrigine were made in response to hypomanic, manic, or depressive symptoms. It is not clear whether the dosages of concomitant psychotropic drugs remained the same during pregnancy. Of the three women requiring a dosage increase to manage symptoms, two were also taking antidepressants that can increase the recurrence of bipolar mood episodes both during and after pregnancy (2). There are no data suggesting that monitoring serum levels with corresponding adjustments to lamotrigine dosing will protect against antidepressant-led mood instability. Interestingly, the authors did not report a correlation between lamotrigine concentration and scores on rating scales for depression and mania. Thus, the conclusion that women with bipolar disorder who are treated with lamotrigine experience an increase in symptoms as a result of declining concentrations of this drug is not justified.

While lamotrigine has a role in the management of bipolar disorder during pregnancy, no data on its effectiveness in the prevention of postpartum mood episodes are currently available. Moreover, lamotrigine is generally not recommended for the acute treatment of mania (3).

Finally, the statement that pregnancy is a vulnerable period for recurrence of mood episodes is true for women treated at tertiary care centers with complex and often comorbid disorders and women who discontinue mood-stabilizing drugs. However, evidence from studies using nonclinical samples, retrospective studies, and studies on psychiatric hospitalization rates is suggestive of a positive effect of pregnancy on bipolar disorder (4).