To BD or Not to Diagnose BD: That's the Question

CONFERENCE REPORTER

“You may stand on either side of the fence when it comes to misdiagnosis in bipolar disorder: Is it underdiagnosed? Is it overdiagnosed?” Joseph F. Goldberg, MD, said to attendees of the 2023 Psychiatric Times World CME Conference. “The overarching message I hope to send to you today is that bipolar disorder is within the differential diagnosis of mood disorders, it’s an important element in that differential diagnosis, and you don’t want to miss it.”

One of the issues in making the differential diagnosis are the tools available to clinicians, he explained. “There’s no biopsy, there’s no definite test when we talk about accurate diagnoses,” said Goldberg, clinical professor in the Department of Psychiatry at Icahn School of Medicine at Mount Sinai. “What we’re really talking about is reliable diagnoses, where you and I can both agree that we see corresponds to an image we have in our mind of a clinical entity that’s got some predictable phenomenology and, of course, outcomes.” Perhaps that’s why over time there have been estimates that bipolar disorder has been over- and underdiagnosed. In an early study, researchers found about 40% of patients were misidentified as having a unipolar disorder when, after a thorough diagnostic assessment, they actually met criteria for bipolar disorder.¹ A later study found about half of those individuals who had been diagnosed with bipolar disorder did not meet the DSM criteria.² The fault may partially fall on the screeners, Goldberg said, as the bipolar disorder inter-rater reliability is 0.56, which is considered “good,” but not “very good.”

Further complicating the differential diagnosis is the high degree of comorbidity. “Psychiatric comorbidity is the rule, not the exception, in people with bipolar disorder,” Goldberg explained. “Most people with bipolar disorder have a second psychiatric diagnosis—about three-quarters [of patients with bipolar disorder]. About 1 out of 2 will have 2 psychiatric comorbidities, and a quarter will have 3 or more psychiatric comorbidities.”

With that in mind, on what should clinicians focus when conducting differential diagnosis? Goldberg shared a number of helpful considerations. If a patient presents with a depressive disorder, for example, he said clinicians should investigate for a history of mania and hypomania. When deciding between schizoaffective disorder and bipolar disorder with psychotic features, the latter is the case if the psychotic symptoms occur exclusively during manic or depressive episodes. Similarly, anxiety disorder may mimic mania or hypomania, like when patients say they are up all night long with racing thoughts, he explained. Here it is important to differentiate ruminations versus racing thoughts and compulsions to manage anxiety versus impulsive behaviors.

Distinguishing between bipolar disorder and borderline personality disorder also can be challenging, especially since there is quite a bit of comorbidity. In a 4-year study, for example, 19% of patients with borderline personality disorder also met DSM-IV criteria for a manic or hypomanic episode,⁴ and another study found 17% of patients with bipolar also met DSM-IV criteria for borderline personality disorder.⁵ That’s why Goldberg focuses on those symptoms that don’t overlap in conducting a differential diagnosis.

He posed the following scenario: “You tell me, ‘I’m seeing this patient who’s got mood instability and irritability, and they’re impulsive and agitated and risk-taking.’ And I will say to you, ‘That doesn’t help me. Tell me about the non-overlapping symptoms,” he told attendees.

Some key indicators include the length of time of mood episodes. If they are short, lasting minutes to hours, and if they are triggered by interpersonal disputes, Goldberg told attendees borderline personality disorder should be considered. But if they the mood lasts days to week and is triggered by chronobiological events, then he would consider bipolar disorder. Euphoria, depression, euthymia are indicative of bipolar disorder, he added, while anger depression, and feeling empty is indicative of borderline personality disorder. Similarly, nonsuicidal injury is rare in patients with bipolar disorder, but this behavior is common in borderline personality disorder and can also assist in the differential diagnosis.

The same process can be leveraged when considering attention-deficit/hyperactivity disorder (ADHD), Goldberg explained. Comorbidity is likewise high with these disorders, he said, with about 10% to 20% of adults with bipolar disorder also having comorbid ADHD. Similarly, symptoms like mood instability, inattention, and impulsivity occur both in ADHD and bipolar, so clinicians should focus on the non-overlapping symptoms. Definable and discrete episodes, prominent depression, suicidality, grandiosity, and hypersexuality are more indicative of bipolar disorder, Goldberg explained. Meanwhile, onset in childhood, chronic symptoms, and fatigue resulting from diminished sleep indicate ADHD. 

Ultimately, Goldberg told attendees “diagnostic accuracy depends on careful symptom assessment, longitudinal course, recognition of confounding factors and comorbidities, awareness of epidemiological benchmarks, family history, and response to treatment.” With that in mind, he recommended considering a working/provisional diagnoses that can be re-assessed as longitudinal data becomes available. “We can certainly come back and confirm over time if bipolar disorder is or isn’t the right name for this ailment.”

Attending a conference? Share your thoughts and clinical pearls, and your summary may be featured in an upcoming issue of Psychiatric Times. Email us at PTEditor@mmhgroup.com.

References

1. Ghaemi SN, Sachs GS, Chiou AM, Pandurangi AK, Goodwin K. Is bipolar disorder still underdiagnosed? Are antidepressants overutilized? J Affect Disord. 1999;52(1-3):135-144.

2. Zimmerman M, Ruggero CJ, Chelminski I, Young D. Is bipolar disorder overdiagnosed? J Clin Psychiatry. 2008;69(6):935-940.

3. Krishnan KR. Psychiatric and medical comorbidities of bipolar disorder. Psychosom Med. 2005;67(1):1-8.

4. Gunderson JG, Weinberg I, Daversa MT, et al. Descriptive and longitudinal observations on the relationship of borderline personality disorder and bipolar disorder. Am J Psychiatry. 2006;163(7):1173-1178.

5. Garno JL, Goldberg JF, Ramirez PM, Ritzler BA. Impact of childhood abuse on the clinical course of bipolar disorder. Br J Psychiatry. 2005;186:121-125.