About 15% of women experience a depressive episode after the birth of a child. While most women who show symptoms of depression have unipolar depression, some women actually do bipolar depression. At this juncture, the correct diagnosis is crucial, as the treatment of bipolar depression differs from the treatments commonly used for unipolar depression in this setting. Using antidepressants in a woman with bipolar disorder may not be effective and may actually make symptoms worse.
While women with bipolar disorder before birth may experience maternal or postpartum psychosis after giving birth, it is important to remember that it is more common for women to experience depressive symptoms in this setting.
First, a thorough review of the psychiatric history
The first step in making this distinction is a careful review of past psychiatric symptoms. The following questions will help clinicians identify individuals with a history of bipolar disorder or symptoms suggestive of bipolar disorder:
- Has the patient previously received a diagnosis of bipolar disorder?
- Has the patient been previously treated with mood stabilizers such as lithium, lamotrigine, or atypical antipsychotic agents?
- Does the patient have a history of mania or hypomania? The Mood Disorders Questionnaire or MDQ is a standardized questionnaire that may be useful in screening for manic or mixed symptoms. Here is one printable version of the MDQ.
- Is there a family history of bipolar disorder? If one parent has bipolar disorder, there is a 10% to 25% chance that they will have bipolar disorder. The risk is higher if several family members are affected.
In people who show symptoms of postpartum depression, the correct diagnosis can be difficult. It is not difficult to recognize a full manic episode. However, most women with bipolar disorder do not experience classic manic symptoms. In fact, for many women with bipolar disorder, depressive episodes are more common than manic episodes. It is quite common for the first episode of bipolar disorder to be depressive in nature, and this episode may occur before the onset of a hypomanic or manic episode.
Making the diagnosis in women without a history of bipolar disorder
When there is no history of bipolar disorder, is it possible to distinguish unipolar from bipolar depression? In a large cohort study of patients with bipolar disorder, researchers sought to identify clinical and demographic characteristics that might help clinicians distinguish bipolar from unipolar depression in postpartum individuals.
Using data from FACE-BD (FondaMental Academic Centers of Expertise for Bipolar Disorders), a French multicenter cohort of patients with bipolar disorder, researchers identified all women who reported a major depressive episode as their first episode of bipolar disorder and had at least one child . They compared two groups of women, depending on whether the onset of bipolar disease occurred during or outside the postpartum period.
Among the 759 women in this cohort, 93 (12.2%) had postpartum onset of bipolar illness and 666 (87.8%) had onset outside of the postpartum period. Women who had a postpartum episode of bipolar disorder had more stable family lives, more children, and were older at onset. They were more likely to have Bipolar Disorder Type 2, less likely to have a history of suicide attempts, and had fewer depressive episodes.
Although this is one of the few studies examining features that may help clinicians distinguish unipolar from bipolar postpartum depression, the information is of limited clinical utility. However, it can provide some reassurance. onset of bipolar disorder (with depression) in the postpartum period is less common than non-postpartum onset. In addition, it appears that women who experience bipolar depression in the postpartum period tend to have less severe illness (fewer depressive episodes, fewer suicide attempts, lower risk of mania) and have higher levels of family support.
Use of the Mood Disorder Questionnaire to identify bipolar depression
Vigilance is required in screening women who present with symptoms of depression during the postpartum period. Women with bipolar depression, as well as unipolar depression, typically have elevated scores on the Edinburgh Postnatal Depression Scale. In a study where the EPDS was used to screen postpartum women, approximately one-third of women with a positive screen on the EPDS did not have unipolar depression but actually had bipolar disorder. In other words, if we used the EPDS as our only tool to guide diagnosis and treatment, we would be wrong about 30% of the time.
A recent study evaluated the ability of the Mood Disorder Questionnaire (MDQ) to identify bipolar disorder in perinatal subjects who screened positive for depression on the Patient Health Questionnaire-9, a screening tool commonly used to identify depression in perinatal populations. (Millan et al. 2023).
Between January 2017 and April 2021, 1510 pregnant or postpartum subjects were included in this study. In this group of perinatal individuals who scored positive on the PHQ-9 (cutoff 10 or greater), 62 (4.1%) were diagnosed with bipolar disorder confirmed by clinical assessment using the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, diagnostic criteria.
The first question of the MDQ includes 13 yes or no items about current and past bipolar symptoms. While a score of 7 or greater on Question 1 of the MDQ is typically used to identify individuals with bipolar disorder in the general population, this cutoff when used in the perinatal population had a sensitivity of 60% and a specificity of 88%. This means that if we used a cut-off score of 7, approximately 40% of subjects who screened positive on the PHQ-9 would be misdiagnosed with unipolar depression when in fact they had bipolar depression.
Lowering the MDQ cutoff score to 4 or greater resulted in increased sensitivity (81%), at the expense of specificity (69%). This modification may lead to a higher number of false positives (patients who actually have unipolar depression). However, it reduces the chance of misidentifying people with bipolar disorder.
This study suggests that as an adjunct to routine screening with the EPDS or PHQ-9, administration of the Mood Disorder Questionnaire during the perinatal period may help identify individuals who are more likely to have bipolar or unipolar disorder. In this context, the researchers observed that lowering the cut-off score for the MDQ to 4 or more reduces the risk of not being diagnosed with bipolar disorder.
Some Final Thoughts
Diagnosing bipolar depression in the postpartum period can be extremely difficult, and even the most experienced clinicians may struggle to accurately distinguish unipolar from bipolar depression in this setting. While the use of standardized screening tools may help identify a greater number of women with psychiatric illness in the perinatal period, it is important to recognize that screening tools are not a substitute for clinical diagnosis. They simply identify those who need a more thorough assessment.
Using screening tools such as the EPDS or PHQ-9 recognize women with a wide range of psychiatric disorders, including major depressive disorder, bipolar disorder, PTSD, generalized anxiety disorder. Further evaluation is required to confirm the diagnosis. In situations where there is limited access to mental health resources, the use of additional screening tools such as the Mood Disorder Questionnaire can help clinicians identify women with bipolar disorder and ensure that these individuals receive appropriate care.
Ruta Nonacs, MD PhD
BIBLIOGRAPHICAL REFERENCES
Millan DM, Clark CT, Sakowicz A, Grobman WA, Miller ES. Optimization of the mood disorder questionnaire in the identification of perinatal bipolar disorder. Am J Obstet Gynecol MFM. 2023 Jan. 5(1):100777.
Tebeka S, Godin O, Mazer N, Bellivier F, et al. Clinical features of bipolar disorders with postpartum depression. Prog Neuropsychopharmacol Biol Psychiatry. 2020 December 18.
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