[Editor’s Note: A small segment of my readers who were initially diagnosed with postpartum depression have learned down the road that they have bipolar disorder. Other readers who have been treated for a year or more for postpartum depression but feel the treatment isn’t working have also inquired whether it may be that they were misdiagnosed with PPD and could actually have bipolar disorder. I reached out to perinatal mood and anxiety expert Karen Kleiman, MSW, LCSW, to help shed some light on the differences between postpartum depression and bipolar disorder. -Katherine]

I’m sharing this information for both postpartum moms and clinicians in response to Katherine, who reached out to me because she’s received a number of inquiries about the relationship between postpartum depression and bipolar illness. I’m hoping this can offer some clarification.

To date, research on bipolar disorder and postpartum depression and related illnesses typically focuses on bipolar I and psychosis. According to the research, bipolar depression is often misdiagnosed as major depressive disorder during the postpartum period. [Editor’s note: For the readers, major depressive disorder during the postpartum period is a diagnostic term for what you know as postpartum depression.] What does this mean? For one thing, it certainly can delay appropriate treatment.

It also raises the following clinical questions for therapists:

1) Are we overlooking hypomanic symptoms during the postpartum period because they overlap with the “normal” elation of new motherhood?

2) Are we being particularly vigilant during the early postpartum weeks when the peak prevalence of hypomania occurs?

3) Are we forgetting to include a bipolar screen when we are assessing postpartum women?

And it raises questions for postpartum moms:

1) Does your provider know if you have a history of bipolar illness?

2) Are you familiar with the symptoms of bipolar illness so you and your family can be informed consumers?

3) Are you satisfied with the course of your treatment or do you need another opinion or discussion with your provider?

4) Are you reporting symptoms of hypomania or are you only concerned with symptoms of depression?

Let’s start with some definitions.

Bipolar spectrum disorder includes Bipolar I, Bipolar II, and Bipolar NOS (not otherwise specified). Bipolar I is defined by recurrent episodes of mania and depression, while bipolar II is characterized by recurrent episodes of depression and hypomania. [Editor’s note: See below for an explanation of the different between mania and hypomania.] Bipolar NOS is the presence of mania and depressive symptoms but does not meet diagnostic criteria for bipolar I.

Bipolar Disorder NOS is diagnosed when symptoms do not meet diagnostic criteria (in the DSM-IV) for either bipolar I or bipolar II. Although the symptoms are beyond the normal range of behavior for a particular person, the symptoms may not last long enough, be severe enough, or there may be too few to be diagnosed with bipolar I or II.

Mania is a mood state most commonly characterized by excessive energy—it can feel as though you have an endless supply of energy—and a decreased need to sleep. This is NOT an inability to sleep because of a wakeful baby or anxious thoughts; rather, it refers to a decrease in sleep requirement. Other symptoms include: rapid speech (and changing topics frequently), grandiose (extremely boastful) thinking, abnormally elevated mood with impaired judgment, rash or reckless spending and hypersexuality. Psychotic symptoms, such as hallucinations, may also be present. Symptoms are persistent and interfere substantially with one’s ability to function.

Hypomania literally means “below mania,” in other words, less severe mania symptoms. Most mania symptoms are present in hypomania, but are less intense. It is characterized by a distinct period of persistently elevated or irritable mood for at least four days. Symptoms may interfere with functioning to some degree but the impairment may not be noticeable. No symptoms of psychosis (for example, hallucinations, delusions, or paranoia) are present in hypomania.

Regarding diagnoses, an important marker is the time frame. For instance, even though there is some degree of euphoria considered to be normal during baby blues (the first couple weeks after baby is born), symptoms of postpartum hypomania are usually present at day one, as opposed to day three or four. Hypomania is clinically significant because it can be a precursor to bipolar manifestations later.

Screening for bipolar symptoms is essential. At the Postpartum Stress Center, we use the MDQ (Mood Disorder Questionnaire). It may feel heavy-handed to both the clinician and the postpartum mom, but it’s important to rule out hypomania, especially during the very early postpartum days and weeks.

Diagnosis of Bipolar Illness

So, how do you know if you’ve been misdiagnosed with postpartum depression and may actually have bipolar illness?

To be diagnosed with Bipolar I, you must have at least one manic episode lasting for at least a week. Usually, there is also the presence of depressive episodes, typically lasting at least two weeks.

For a diagnosis of Bipolar II, you must have had at least one hypomanic episode and at least one depressive episode. There can be a pattern of depressive episodes shifting with hypomanic episodes, with no history of a manic episode.

Misdiagnosis of Bipolar Illness

Misdiagnosis of bipolar illness can occur in two ways. It can occur by failure to recognize the symptoms, leading some experts to believe it is under diagnosed. Other times, it can be over diagnosed, particularly in some hospital in-patient settings, where doctors see a high proportion of severely distressed or suicidal women. People who present with extreme anxiety and restlessness might be misdiagnosed with bipolar disorder. Although anxiety and restlessness could be present with bipolar disorder, these symptoms would also need to be associated with additional specific criteria, such as feeling energetic in spite of sleeplessness, or inflated self-esteem for example.

During the postpartum period, a healthcare provider might confuse early euphoria as consistent with the joy of new motherhood, and perhaps may not ask the right questions to make a differential diagnosis, thereby missing the diagnosis. Other times the opposite is the case; women with postpartum depression may be extremely agitated and risk being misdiagnosed as bipolar to the untrained eye. Although this may sound ambiguous, be clear about this: There are very distinct, discernible criteria that must be met in order for a bipolar diagnosis to be made. This is why appropriate screening is essential.

It is understandable that there is a subset of women who may wonder about their own diagnoses, perhaps because the course of their treatment has not been what they expected or perhaps they are not responding to treatment the way they had hoped. Women may wonder if their PPD has “turned into” bipolar disorder, especially if they are treated with a mood stabilizer further along in their treatment.

Can someone who has been treated for postpartum depression for some time be misdiagnosed? Certainly, that’s possible. Perhaps early hypomanic symptoms were disregarded. Or perhaps there was a family history of mood disorders and the postpartum period created the perfect storm for bipolar disorder to emerge. Whatever the circumstance, be clear about this: Bipolar symptoms don’t hide for too long. If hypomanic symptoms are missed in the early postpartum period, they are likely to emerge in full force later in the postpartum year.

Other potential scenarios for women with enduring or worsening postpartum depression symptoms are:

1) characterologic variables (those pertaining to personality traits), or

2) extenuating environmental circumstances (such as unstable marriage, multiple losses, trauma, to name only a few things that could underlie a sustaining depression)

It should also be noted, in instances where a mood stabilizing medication (often used in the treatment of bipolar illness) is added after months of postpartum depression treatment, it may not necessarily be because there is a new diagnosis of bipolar illness. Rather, there are cases when a mood stabilizer is useful to treat sub-clinical mood changes that are problematic but do not meet the diagnostic criteria for bipolar disorder. If someone came to the Postpartum Stress Center with a long-standing depression that was not responding to medication or psychotherapy, we would not conclude that there is an untreated bipolar illness unless we saw evidence of symptoms that met the DSM-IV criteria. [Editor’s note: The DSM-IV is the book healthcare providers refer to when they diagnose a mental illness.]

The relationship between postpartum depression and bipolar illness is the subject of ongoing research, although thus far research on bipolar II has been lacking. As always, clinicians must be vigilant about screening questions and thorough assessments, and postpartum moms need to advocate for their own best healthcare. If we can maximize our attention to this matter from both angles, we will reduce the likelihood of under- or over-diagnoses.

~ Karen Kleiman, MSW, LCSW

For more on this topic from Postpartum Progress, you might also like:

• The Enticing Euphoria of Hypomania
• The Difference Between Mania & Hypomania 
• How Mania Feels