A new test screens for bipolar disorder with respectable accuracy
Bipolar disorder is difficult to diagnose, but missing it can steer treatment in the wrong direction. Common psychiatric medications like antidepressants and stimulants can cause mania, mixed states, and worsen the overall course of the illness, especially when used without a mood stabilizer.1,2
Researchers led by Roger McIntyre, MD, at the University of Toronto developed a screening tool for bipolar I disorder that patients can complete in 2 minutes: The Rapid Mood Screener (RMS). It was designed to detect bipolar I disorder in primary care, but it is useful as a first step toward clarifying the diagnosis in psychiatric settings as well.
To develop the scale, 6 experts identified 72 items that separate unipolar from bipolar disorder. Those 72 were combined and simplified to yield 10 potential items. Patient interviews helped make the wording more patient-friendly. The 10 items were then reduced to a final 6 that had the best balance of specificity and sensitivity after testing them in 139 patients with bipolar I or major depression. The diagnoses were confirmed by structured interviews with the DSM-IV based MINI Neuropsychiatric Interview.3
The final scale had better predictive properties than most of the currently available self-rated tests for bipolar disorder, with a sensitivity of 0.88 and a specificity of 0.80. By comparison, the Mood Disorder Questionnaire (MDQ) had a sensitivity of 0.76 and a specificity of 0.81 when it was used to separate bipolar and unipolar depression.4
To put that in practical terms, both the RMS and the MDQ have similar rates of false positives. They will incorrectly identify a patient with bipolar disorder 1 out of 5 times. Where the RMS shines is in it sensitivity to detect the illness. The RMS will only miss about 1 in 10 true cases of bipolar disorder, while the MDQ will miss 1 in 4.
However, the RMS was only tested in bipolar I disorder, and rating scales that do a good job of identifying bipolar I are not always as successful at detecting the subtle hypomania of bipolar II. For that work, I recommend the Hypomanic Check List-32 or the Bipolarity Index, or removing the final severity criteria from the MDQ (this last idea has been tested, and makes intuitive sense: Hypomania does not cause severe problems).5
The final 6 items of the RMS are:
1. Have there been at least 6 different periods of time (at least 2 weeks) when you felt deeply depressed?
2. Did you have problems with depression before the age of 18?
3. Have you ever had to stop or change your antidepressant because it made you highly irritable or hyper?
4. Have you ever had a period of at least 1 week during which you were more talkative than normal with thoughts racing in your head?
5. Have you ever had a period of at least 1 week during which you felt any of the following: unusually happy; unusually outgoing; or unusually energetic?
6. Have you ever had a period of at least 1 week during which you needed much less sleep than usual?
The optimal cut-off when testing this scale in patients with mood disorders is at least 4 positive items.
These 4 “runners-up” did not make the final cut. They are useful items, particularly the family history one, but they ultimately did not enhance the sensitivity and specificity enough in this study.
1. Has anyone in your family ever been diagnosed with or treated for any of the following: bipolar disorder; problems with drugs or alcohol; or “nervous breakdown”?
2. Have you ever been diagnosed with or treated for any of the following: an anxiety-related condition; ADD/ADHD; or problems with drugs or alcohol?
3. Have you ever been admitted to the hospital for reasons related to your mood, emotions, or behavior?
4. Have you tried at least 3 different antidepressants to treat your depression?
1. Viktorin A, Rydén E, Thase ME, et al. The risk of treatment-emergent mania with methylphenidate in bipolar disorder.Am J Psychiatry. 2017;174(4):341-348.
2. Viktorin A, Lichtenstein P, Thase ME, et al. The risk of switch to mania in patients with bipolar disorder during treatment with an antidepressant alone and in combination with a mood stabilizer.Am J Psychiatry. 2014;171(10):1067-1073.
3. McIntyre RS, Patel MD, Masand PS, et al. The Rapid Mood Screener (RMS): a novel and pragmatic screener for bipolar I disorder. Curr Med Res Opin. 2021;1-17.
4. Wang HR, Woo YS, Ahn HS, Ahn IM, Kim HJ, Bahk WM. The validity of the mood disorder questionnaire for screening bipolar disorder: A meta-analysis.Depress Anxiety. 2015;32(7):527-538.
5. Benazzi F. Improving the Mood Disorder Questionnaire to detect bipolar II disorder.Can J Psychiatry. 2003;48(11):770-771.